Bicycle rear suspension system

A bicycle may include a front triangle and a rear suspension system that couples the front triangle to a rear wheel and is dampened by at least one shock absorber. The rear suspension system includes a six-bar linkage having two ternary links separated from each other by one or more binary links, such that the two ternary links do not share a common joint. One of the ternary links may comprise a chain stay. In some examples, the other ternary link may comprise the front triangle. In some examples, the other ternary link may comprise a rocker arm coupling a seat stay link to the shock absorber.

FIELD

This disclosure relates to bicycle rear suspension systems. More specifically, the disclosed embodiments relate to bicycles having a rear suspension system comprising a six-bar linkage.

INTRODUCTION

A bicycle rear suspension system improves bicycle comfort and performance, particularly for mountain bicycles, by allowing the rear wheel of the bicycle to track the terrain to some extent. This improves rider comfort by reducing the jarring effects felt when passing over uneven terrain on a so-called “hard tail” mountain bicycle (i.e., one that lacks a rear suspension system), and improves performance by increasing traction between the bicycle and the terrain while pedaling, turning and braking.

Various bicycle rear suspension systems have previously been developed. For example, U.S. Pat. No. 5,628,524 to Klassen et al. describes a rear suspension system in which a pair of rotatable links connects the rear triangle of a bicycle to the front triangle and a shock absorber, in a manner resulting in an s-shaped travel path of the rear wheel as the shock absorber is compressed. U.S. Pat. No. 8,066,297 also describes a rear suspension system including a pair of rotatable links connecting the rear triangle to the front triangle and a shock absorber, in which one of the links changes its direction of rotation as the shock absorber is compressed, resulting in improved riding characteristics.

U.S. Pat. No. 8,998,235 to Beale describes a rear suspension system in which three rotatable linkage members connect the rear wheel of a bicycle to the front triangle and a shock absorber. Systems such as these may be referred to as “four-bar linkage systems,” with the three linkage members accounting for three of the “bars” and the front triangle accounting for the fourth bar. Four-bar linkage systems may have rear wheel and pedal-related variables which are dependent upon variables related to the shock absorber. It may be desirable to have these two sets of variables independent from one another. Systems such as described in U.S. Pat. No. 8,988,235 to Beale may also have acceleration anti-squat values which are related to braking anti-rise values. It may be advantageous to have anti-squat decoupled from anti-rise. These variables and values are described in greater detail below.

One goal of a rear suspension system such as those described above is to provide a relatively firm response to pedaling inputs, as when ascending or riding on smooth ground, but also to provide a relatively forgiving response to bumps or terrain inputs, as when descending or encountering rough terrain. This reduces the unwanted loss of pedaling energy due to unnecessary shock absorption, while preserving the desirable properties of the suspension system. There remains significant room for improvement in this regard.

SUMMARY

The present disclosure provides systems, apparatuses, and methods relating to rear suspension systems for bicycles.

In some embodiments, a bicycle may include: a frame including a rigid front triangle; and a rear suspension system having a shock absorber and coupling the front triangle to a rear wheel, the rear suspension in combination with the front triangle comprising a six-bar linkage having exactly two ternary links separated from each other by at least one binary link, such that the two ternary links have no joints in common; wherein a first ternary link of the two ternary links comprises a chain stay link.

In some embodiments, a bicycle may include: a bicycle frame; and a rear suspension system coupling the bicycle frame to a rear wheel, the rear suspension system in combination with the frame comprising a six-bar linkage, the six-bar linkage including: a chain stay link comprising a first ternary link coupled at a front end portion by a first joint to a first binary link and by a second joint to a second binary link, and coupled at a rear end portion by a third joint to a seat stay link comprising a third binary link; a fourth binary link coupled by a fourth joint to the seat stay link; wherein the first binary link is coupled to the bicycle frame by a fifth joint, the second binary link is coupled to the bicycle frame by a sixth joint, and the fourth binary link is coupled to the bicycle frame by a seventh joint, such that the bicycle frame is a second ternary link of the six-bar linkage; and a shock absorber coupling the fourth binary link to the bicycle frame.

In some embodiments, a bicycle may include: a bicycle frame; and a rear suspension system coupling the bicycle frame to a rear wheel, the rear suspension system in combination with the frame comprising a six-bar linkage, the six-bar linkage including: a chain stay link comprising a first ternary link coupled at a front end portion by a first joint to a first binary link and by a second joint to a second binary link, and coupled at a rear end portion by a third joint to a seat stay link comprising a third binary link; a rocker arm coupled by a fourth joint to the seat stay link; wherein the first binary link is coupled to the rocker arm by a fifth joint, the second binary link is coupled to the bicycle frame by a sixth joint, and the rocker arm is coupled to the bicycle frame by a seventh joint, such that the rocker arm comprises a second ternary link of the six-bar linkage and the bicycle frame comprises a fourth binary link of the six-bar linkage; and a shock absorber coupling the fourth binary link to the bicycle frame.

DESCRIPTION

Definitions

Furthermore, the present disclosure generally relates to a bicycle rear suspension system having particularly desirable riding characteristics. These characteristics result from a particular configuration of frame portions and linkage members that will be described using various terms that have standard meanings in the field of suspension systems. These terms include:

“Instant center” means the intersection point of two lines, each of which represents the linear extension of one of the linkage members in the suspension system. Note that a six-bar linkage system may have a plurality of instant centers.

“Center of curvature” means the center of a circle that intersects the axle of the rear wheel of the bicycle and has a radius determined from the instantaneous travel path of the rear wheel.

“Shock rate” means the ratio of shock compression distance to rear wheel travel distance.

“Sag” means the compression of the shock absorber when the shock absorber is compressed by the weight of the rider on the bike.

“Chainstay length” or “CSL” means the distance from the axis of the bicycle bottom bracket (i.e., the axis around which both pedals rotate) to the rear wheel axis.

“Chainstay lengthening” or “dCSL” means the rate of change of chainstay length as the shock is compressed, or alternatively as the rear wheel of the bicycle moves vertically upward. The rate of change of chainstay length may be computed relative to vertical wheel travel distance.

“d2CSL” means the rate of change of dCSL as the shock is compressed or as the rear wheel of the bicycle moves vertically upward. The rate of change of dCSL may be computed relative to vertical wheel travel distance.

“Braking anti-rise” is a measure of the suspension system's response to braking, and is defined as a ratio calculated as follows. First, a line is drawn between the point of contact of the rear wheel with the ground and the instant center (defined above). Then the intersection of this line with a vertical line passing through the front wheel axle is found. The height of this intersection point above the ground divided by the height of the center of gravity of the bicycle and the rider is the braking anti-rise value. It is frequently multiplied by 100 and expressed as a percentage.

“Acceleration anti-squat” is a measure of the suspension system's response to acceleration, and is defined as a ratio calculated as follows. First, a line is drawn between the rear wheel axis and the instant center (defined above). A second line is drawn as the chain force line between the front chainring and the rear cassette gear (for a given gear ratio). A third line is then drawn through the intersection of the first line (rear wheel point of contact to instant center) and the second line (chain drive force line) and the rear wheel point of contact. Then the intersection of the third line with a vertical line passing through the front wheel axle is found. The height of this intersection point above the ground divided by the height of the center of gravity of the bicycle and the rider is the acceleration anti-squat value. It is frequently multiplied by one hundred, and expressed as a percentage.

A “Stephenson chain” is a type of six-bar linkage having one four-bar loop and one five-bar loop, the linkage including two ternary (i.e., three-joint) links that are separated from each other by one or more binary (i.e., two-joint) links. Unlike the Watt type of six-bar linkage, the two ternary links of a Stephenson chain are not connected to each other by a shared joint (i.e., no joints in common).

Overview

In general, bicycle rear suspension systems of the present disclosure may include a six-bar linkage connecting a front triangle of the bike frame to the rear wheel. Links of the six-bar linkage may have varying lengths and arrangements. In general, a planar, one degree-of-freedom linkage in the general form known as a Stephenson chain may be utilized, with two ternary links separated by one or more binary links. For example, a so-called “Stephenson II” or “Stephenson III” topology may be utilized. Motion of the linkage may be dampened, e.g., by a shock absorber device coupled to one or more of the links.

Use of a six-bar linkage in accordance with aspects of the present disclosure may provide an improved rear suspension as compared to other topologies. Typical four-bar suspension systems have an inherent dependency characteristic present in all of the tuned variables of the system. Specifically, in four-bar suspension systems, if one of the performance variables changes significantly as the suspension moves from full extension to full compression, then other variables will as well. For example, there is a relationship between dCSL and the shock rate, and there is a relationship between pedaling anti-squat and shock rate.

Six-bar systems according to the present teachings allow for greater separation of pedal performance variables from shock performance variables, essentially giving the system one characteristic for pedaling performance and a separate characteristic for shock performance. Because of the increased number of links in the linkage, it is possible to have high rates of change in chain growth (dCSL and d2CSL)—a desirable goal for pedaling performance—while having very linear (or at least monotonic) changes in shock rate/leverage ratio—a desirable goal for shock tuning. Accordingly, the shock rate can be tuned independently from dCSL and independently from the anti-squat.

Because there is separation between pedal performance variables and shock tuning variables, it is possible to adjust the geometry of the bike (primarily by changing the position of the rear axle relative to the bottom bracket) without making changes to the shock rate. Geometry can be adjusted more easily for different sizes of bikes without changing key kinematic relationships of the suspension system.

The following sections describe selected aspects of exemplary rear suspension systems for bicycles, as well as related systems and/or methods. The examples in these sections are intended for illustration and should not be interpreted as limiting the entire scope of the present disclosure. Each section may include one or more distinct embodiments or examples, and/or contextual or related information, function, and/or structure.

A. First Illustrative Embodiment

This example describes an illustrative rear suspension bicycle; seeFIGS. 1-2.

FIGS. 1 through 3depict a schematic right side view of portions of an embodiment of a rear suspension bicycle, generally indicated at100. For simplicity,FIG. 1shows portions of the frame of the bicycle. Remaining portions of the bicycle, such as a seat, handlebars, wheels, gears, derailleurs, etc., are unrelated to the present teachings and are either not shown or are only shown schematically. These components are well known in the bicycle art.

Bicycle100includes a front triangle102, a rear wheel104having a rear wheel axis AW, and a rear triangle, generally indicated at106. Rear triangle106comprises a six-bar linkage having a Stephenson III topology, with five links that move relative to a stationary or ground link formed by the front triangle (i.e., the frame, in this case the seat tube). Accordingly, bicycle100includes a first link108, a second link110, a third link112, a fourth link114, and a fifth link116, each of which comprises a respective, single, substantially rigid member pivotably coupled to one or more of the other links as described below. Second link110may be described as a chain stay link, because it is in a frame position typical of a bicycle chain stay. Similarly, third link112may be described as a seat stay link, because it is in a frame position typical of a bicycle seat stay. Bicycle100further includes a shock absorber118, which is coupled to the linkage at a forward extension of link114as shown inFIG. 1. Generally, the first through fifth links (also referred to as linkage members) allow the rear wheel axis AWto move relative to the front triangle as the shock absorber is compressed. Said another way, the rear wheel pivots relative to the front triangle as a result of the linkage, and this motion is dampened and, in part, limited by shock absorber118.

In some examples, certain features of bicycle100may be symmetric with respect to the plane defined by the bicycle. For example, any of the first through fifth links108,110,112,114, and116may be right-hand links and bicycle100may further include corresponding left-hand links. The left-hand links may be mirror images of the right-hand links and may otherwise be identical. In some cases, a left-hand link and a right-hand link may form a substantially rigid, symmetric, link extending on both left and right sides of the bicycle. Accordingly, any description of a link should be understood to apply equally well to its symmetric counterpart or to one side of a single, symmetric link.

In some examples, certain features of bicycle100may be asymmetric with respect to the plane defined by the bicycle. In particular, a right-hand component and a left-hand component may have a same projection into the plane defined by the bicycle but may each be disposed a different distance away from the plane of the bicycle. That is, one side of the bicycle may have one or more components closer to or farther from the center line of the bicycle to accommodate, for example, the drivetrain which is usually disposed on only one side of the bicycle. In some examples, a component on one side of the bicycle may be curved while the corresponding component on the other side of the bicycle may be straight.

With continuing reference toFIGS. 1-3, an overview of the six links and seven joints of the six-bar linkage will now be provided. In general, any or all of the joints (also referred to as pivotal connections) may include suitable bearings, collets, and/or the like. In this example, second link110and the frame of front triangle102are each ternary links, i.e., having three pivoting joints connecting each of them to other links of the linkage. Specifically, second link110is coupled at a front end to first link108by a first rotating joint120and to fifth link116by a second rotating joint122, and further coupled at a rear end to third link112by a third rotating joint124. Front triangle102is coupled to fourth link114by a fourth rotating joint126, to fifth link116by a fifth rotating joint128, and to first link108by a sixth rotating joint130.

Accordingly, the four binary links are connected in the linkage as follows. Binary link108is coupled at a front end to the front triangle by joint130and at a rear end to the second link by joint120. Binary link116is coupled at a front end to the front triangle by joint128and at a rear end to the second link by joint122. Finally, binary link112is joined to binary link114by a seventh rotating joint132, and to ternary link110by joint124.

Due to the spacing of joints120and122, second link110has a generally triangular shape, as shown inFIGS. 1-3. However, link110may be shaped in any suitable manner that comports with the triangular relationship between its three joints. For example, link110may have a solid triangular shape, may be formed of three legs or members arranged in a triangle, or may include fewer or more legs arranged in a rigid formation facilitating the spacing of joints120,122, and124. For simplicity, link110is shown as a rigid, triangular structure.

In addition to the links and joints that comprise the overall six-bar linkage, other connections and features may be present to facilitate use of the linkage in a rear suspension system. For example, third link112is a binary link, but includes an additional rotational joint134at axis AWwhere rear wheel104is coupled to the suspension. Joint134is proximate to but offset from third rotating joint124by a selected distance, e.g., to avoid interference between the wheel axle/hub and the linkage. In some examples, this selected distance is less than approximately 200 mm.

In some examples, this selected distance is less than approximately 100 mm. The selected distance may be measured center-to-center on the joints. In some examples, rear wheel104may be connected to the chain stay link (i.e., second link110) instead of the seat stay link (i.e., third link112) in a similar fashion.

Accordingly, third link112is also shown as a rigid triangular arrangement of three members, but may include any suitable shape or number of structural members configured to maintain the relationship between the rotating joints. Additionally, fourth link114extends forward of fourth rotating joint126, creating a pivoting rocker arm having its fulcrum at joint126. At the forward end of the rocker arm, a pivotal connection136couples link114to shock absorber118, thereby providing a mechanical dampener for the linkage by affecting rotation of link114.

Front triangle102includes a bottom bracket shell140defining a pedaling axis AP, a seat tube142providing for attachment of a seat post (not shown), a down tube144, and a top tube146. Shock absorber118may be disposed in front of the seat tube and the shock absorber may have a substantially vertical orientation, e.g., generally parallel to the seat tube. A pivotal connection138couples the shock absorber and the front triangle, and is disposed on down tube144proximate bottom bracket shell140.

The depicted generally vertical disposition and orientation of the shock absorber inFIG. 1may have several advantages. In other existing rear suspension bicycles the shock absorber is often attached to the front triangle via the top tube. Coupling the shock absorber to the top tube imparts forces on the top tube that may require a reinforced structure, which may increase the weight of the front triangle. In contrast, as shown inFIG. 1, coupling the shock absorber to the down tube facilitates a lighter top tube.

Another advantage to orienting shock absorber118in a generally vertical orientation proximate the seat tube is the space afforded within the front triangle for other items, such as water bottles, battery packs, etc. That is, bicycle100may have an empty space148between top tube146and down tube144. Empty space148may accommodate a water bottle cage (not shown) which could be attached to the down tube (as is common in standard bicycles). Other existing rear suspension bicycles having a shock absorber coupled to the top tube typically do not have an empty space within the front triangle large enough to accommodate a water bottle cage.

Shock absorber118is configured to attach via pivotal connection138to front triangle102and via pivotal connection136to the fourth link (i.e., the front end portion of the rocker arm). The shock absorber may be coupled to the six-bar linkage of rear triangle106via the fourth link, and is therefore operatively connected to both the front triangle and the rear triangle. During operation of the bicycle, the shock absorber controls the rate and amount of compression of the suspension system due to inputs from bumps and uneven terrain, and thus controls movement of the rear wheel104relative to the front triangle102. The shock absorber typically includes a spring and a damper, or analogous components that function similarly.

Bicycle100may comprise a system, including the six-bar linkage defined by the five links and the front triangle, along with the shock absorber, having one degree of freedom. In other words, a single parameter is needed to specify the spatial pose of the linkage. That is, once a position and orientation any one of the first through fifth links (and/or the shock absorber) is known relative to the front triangle, then a position and orientation of the remainder of the first through fifth links (and/or the shock absorber) may be determined.

The six-bar linkage may be configured such that rear wheel rotation axis AWtraces a non-circular arc when the shock absorber moves between an uncompressed state and a compressed state. The center of curvature, defined above, for the non-circular arc may move generally forward as the shock absorber is compressed. As the center of curvature moves forward, an instantaneous radius of curvature of the trajectory of the rotation axis may increase. That is, the trajectory of the rotation axis may have relatively more curvature proximate a point of minimum compression and relatively less curvature proximate a point of maximum compression.

The center of curvature may move from a first location behind pedaling axis APto a second location behind, but closer to, the pedaling axis as the shock absorber moves between an uncompressed state and a compressed state. Along with any horizontal movement, the center of curvature may also have vertical movement as the shock absorber is compressed or uncompressed.

The shock rate, defined above, for rear suspension bicycle100may rise generally linearly with respect to vertical wheel travel distance as the shock absorber is compressed from as fully uncompressed state to a fully compressed state. A linearly rising shock rate may be desirable. In some examples, the shock rate may rise monotonically with vertical wheel travel distance, if not strictly linearly.

A rate of change of chainstay length, i.e. dCSL defined above, with respect to vertical wheel travel distance may be relatively high when the shock absorber is at sag and relatively low when the shock absorber is more deeply compressed. That is, dCSL may vary with compression in a manner that is independent of how shock rate varies with compression. The variation in dCSL with compression may be the opposite of the variation in shock rate with compression. This independence is illustrated for bicycle100in the charts ofFIGS. 4 and 5.FIG. 4is a chart illustrating the change in dCSL vs. rear wheel travel for bicycle100, andFIG. 5is a chart showing the corresponding change in leverage ratio vs. rear wheel travel. Leverage ratio is the mathematical inverse of shock rate.

The independence of changing shock rate with respect to changing chain stay length is one example of an advantage that six-bar linkage systems may have over linkage systems having fewer links. Namely, systems of the present disclosure may generally separate variables related to the rear wheel and pedaling axes from variables related to the shock absorber. Such rear wheel/pedal related variables may include CSL, dCSL, and d2CSL, among others, and shock absorber related variables may include quantities such as the shock rate and its inverse, the leverage ratio.

In contrast, in rear suspension systems having a four-bar linkage, rear wheel and pedal-related variables may be dependent upon shock-related variables. In particular, for a four-bar linkage suspension to have high levels of chain growth at sag and lower levels of chain growth deeper into travel, the shock rate may also need to be higher at sag and lower deeper into its travel.

FIG. 1shows rear suspension bicycle100where shock absorber118is in a substantially uncompressed state.FIG. 2shows rear suspension bicycle100where shock absorber118is in a partially compressed state. Finally,FIG. 3shows bicycle100where shock absorber118is in a substantially fully compressed state. In moving from the uncompressed state to the compressed state, first link108may first move in a counter clockwise (CCW) direction and then in a clockwise (CW) direction with respect to front joint130, when viewed from the right side as shown inFIGS. 1-3, with the overall movement being CW. Further, second link110may move in a CW direction, third link112may move in a CW direction, fourth link114may move in a CW direction, fifth link116may move in a CCW direction, all with respect to their front linkage joints. In addition to rotations of the links, a center of mass of each link may translate relative to the front triangle as the shock absorber compresses. As the shock absorber compresses, rear wheel axis AWmay move closer to seat tube142.

As described above, bicycle100may have a plurality of instant centers with respect to various arcuate paths, as each of the links may be extended via a line passing through a pair of pivotal joints of that member, and any two of those lines may cross. An example of an instant center is presently described with respect toFIG. 3. First link108may be extended via a line L1passing through its two pivotal connections at joint130and joint120. Fifth link116may be extended via a line L2passing through its two pivotal connections at joint128and joint122. Lines L1and L2cross at an instant center160. It will be appreciated that as the shock absorber is compressed and the first and fifth links rotate, instant center160may move correspondingly.

As mentioned, the first through fifth links may define a plurality of instant centers. Further, a single pair of links may define more than one instant center. For example, second link110has three associated joints (122,126, and128). Three lines may extend through a pair of any two of these pivotal connections and each of these three lines may intersect an extension of another link, say fourth link114, and define another instant center.

In some examples there may be three instant centers for a bicycle. In some examples, if one of the plurality of instant centers has a vertical location that is higher than a vertical location of the remainder of the plurality of instant centers, then the instant center having the highest vertical location may be used to determine such values as acceleration anti-squat and/or braking anti-rise, as described below. In some examples, an effective instant center may be determined based on one or more of the plurality of instant centers of the links.

In some examples, an instant center of bicycle100may move rearward from an initial location to a final location as the shock absorber is compressed from a substantially uncompressed state to a substantially fully compressed state. In some examples, the initial location of an instant center may be in front of pedaling axis AP. In some examples, the final location may be in front of the pedaling axis. An instant center may move in a vertical direction as the shock absorber is compressed.

As described above, an instant center may be used to define other quantities or variables associated with the rear suspension system, such as acceleration anti-squat and braking anti-rise. An example of determining acceleration anti-squat is presently described.

A force line F1may be drawn connecting rear wheel axis AWand instant center160. A chain force line F2may be drawn based on the front chainring and the rear cassette gear. Chain force line F2may be parallel to a top portion of the chain between a rear gear and a front gear. An intersection point162is defined where force line F1crosses chain force line F2. A point of contact164(i.e., a contact patch) is defined between rear wheel104and ground166. A line L3is drawn between point of contact164and intersection point162. A vertical line L4passes through an axle168of a front wheel170of the bicycle. An intersection172of line L3and line L4defines the acceleration anti-squat value as the height H1of intersection172above ground166. Height H1may be divided by a height H2of the combined center of gravity of the bicycle and the rider and multiplied by 100 in order to express the anti-squat value as a percentage. The acceleration anti-squat value may depend upon which instant center is being considered, which gears are engaged by the chain, the size of the rider, and the compression of shock absorber118.

In some examples, the acceleration anti-squat value may decrease as the shock absorber is compressed. In some examples, the acceleration anti-squat value may decrease form a value substantially equal to 100% to a value of substantially equal to zero as the shock absorber is compressed from a fully uncompressed state to a fully compressed state. In some examples, acceleration anti-squat values greater than 100% are possible if the height H1of intersection172is greater than the height H2of the center of gravity. In some examples, acceleration anti-squat values less than zero are possible if intersection172is below ground level.

An example of determining braking anti-rise is presently described. A line L5may be drawn between point of contact164and instant center160. An intersection174is where line L5crosses line L4. A height H3of intersection174above ground166is the braking anti-rise value. This value may be divided by the height H2of the center of gravity and multiplied by 100 in order to express the braking anti-rise as a percentage. The braking anti-rise value may depend upon which instant center is being considered, the size of the rider, and the compression of shock absorber118.

In some examples of bicycle100, the braking anti-rise value may have a period of decrease followed by a period of increase as the shock absorber is compressed from a fully uncompressed state to a fully compressed state. In some examples, the acceleration anti-squat value may be decoupled from the braking anti-rise value as the shock absorber is compressed. In particular, if the acceleration anti-squat value generally decreases, while the braking anti-rise value decreases and then increases as the shock absorber is compressed, then the acceleration anti-squat value may not depend upon the braking anti-rise value.

It may be advantageous to have the acceleration anti-squat value decoupled from the braking anti-rise value. In systems having only three pivotal links the acceleration anti-squat values are often related to the braking anti-rise values. In systems having five pivotal links as described herein, the acceleration anti-squat values may be unrelated to the braking anti-rise values for any particular configuration of the five movable links.

Based on the above, this embodiment may be described as a bicycle having a rear suspension system with a generally linear (or monotonically changing) shock rate, a higher rate of chain stay lengthening in the statically-loaded sag point, and a rear wheel axle disposed on the seat stay link, where the rotating joint between the seat stay link and the chain stay link is located within no more than approximately 100 mm (or in some examples no more than approximately 200 mm).

In this and other embodiments described herein, the seat stay link and the chain stay link are both significantly longer than the remaining movable links. In some examples, the lengths of the seat stay link and the chain stay link are a dominant or major contributing factor to the longitudinal position of the rear wheel relative to the frame and front wheel of the bike. Accordingly, the seat stay link and the chain stay link may be described as being coupled to the frame by the three other movable (in this case binary) links. However, various length combinations and relationships between the various links are possible and within the scope of the present disclosure.

This section describes various additional embodiments of rear suspensions for bicycles according to aspects of the present teachings; seeFIGS. 6-14. All of these additional embodiments may exhibit one or more of the characteristics described above, including (i) pedaling-related variables may be separate or decoupled from shock-related variables, (ii) a change in shock rate or leverage ratio may be independent of a rate of change of chainstay length (dCSL), (iii) generally linear or monotonic increasing shock rate with vertical wheel travel, (iv) decreasing chain growth with vertical wheel travel, and (v) a decreasing anti-squat value as the shock absorber is compressed.

FIGS. 6 and 7are schematic depictions of another illustrative rear suspension bicycle200, which is similar to bicycle100and also comprises an example of a Stephenson III topology. Similar components of bicycle200are named and numbered as their substantially similar counterparts in bicycle100. For example, front triangle202is similar to front triangle102, and is joined to rear wheel204by rear triangle206, corresponding to rear wheel104and rear triangle106. Other than as described below, correspondingly numbered components are substantially as described above.FIG. 6shows bicycle200with a shock absorber218in a substantially uncompressed state andFIG. 7shows bicycle200with shock absorber218in a substantially fully compressed state.

Bicycle200may differ from bicycle100in the exact disposition and orientation of the first through fifth links, here referred to as links208,210,212,214, and216. For example, first link208and fifth link216in this example are joined to the bike frame more closely together than in the example of bicycle100. Specifically, the forward joints are spaced closer together than are the rear joints of these links. In contrast, joints128and130are spaced farther apart than joints120and122(seeFIGS. 1-3). As with bicycle100, second link210may be described as a chain stay link, because it is in a frame position typical of a bicycle chain stay, and third link212may be described as a seat stay link, because it is in a frame position typical of a bicycle seat stay.

With continuing reference toFIGS. 6-7, an overview of the six links and seven joints of this six-bar linkage will now be provided. As described above, any or all of the pivotal connections may include suitable bearings, collets, and/or the like. In this example, second link210and the frame of front triangle202are each ternary links, i.e., having three pivoting joints connecting each of them to other links of the linkage. Specifically, second link210is coupled at a front end to first link208by a first rotating joint220and to fifth link216by a second rotating joint222, and further coupled at a rear end to third link212by a third rotating joint224. Front triangle202is coupled to fourth link214by a fourth rotating joint226, to fifth link216by a fifth rotating joint228, and to first link208by a sixth rotating joint230.

Accordingly, the four binary links are connected in the linkage as follows. Binary link208is coupled at a front end to the front triangle by joint230and at a rear end to the second link by joint220. Binary link216is coupled at a front end to the front triangle by joint228and at a rear end to the second link by joint222. Finally, binary link212is joined to binary link214by a seventh rotating joint232, and to ternary link210by joint224.

Due to the spacing of joints220and222, second link210has a generally triangular shape, as shown inFIGS. 6-7. However, link210may be shaped in any suitable manner that comports with the triangular relationship between its three joints. For example, link210may have a solid triangular shape, may be formed of three legs or members arranged in a triangle, or may include fewer or more legs arranged in a rigid formation facilitating the spacing of joints220,222, and224. For simplicity, link210is shown as a rigid, triangular structure.

In addition to the links and joints that comprise the overall six-bar linkage, other connections and features may be present to facilitate use of the linkage in a rear suspension system. For example, third link212is a binary link, but includes an additional rotational joint234at axis AWwhere rear wheel204is coupled to the suspension. Joint234is offset from third rotating joint224, e.g., to avoid interference between the wheel axle/hub and the linkage. Accordingly, third link212is also shown as a rigid triangular arrangement, but may include any suitable shape or number of structural members configured to maintain the relationship between the rotating joints. Additionally, fourth link214extends forward of fourth rotating joint226, creating a pivoting rocker arm having its fulcrum at joint226. At the forward end of the rocker arm, another rotating joint236couples link214to shock absorber218, thereby providing a mechanical dampener for the linkage by affecting rotation of link214.

As the shock absorber moves from the substantially uncompressed state (FIG. 6) to the substantially compressed state (FIG. 7), all five of the movable links rotate in a CW direction with respect to their respective forward joints. In general, because fifth link216is coupled to front triangle202at a position that is vertically lower than its rear joint222, upward motion of the rear wheel causes the rear end of link216to pivot upward as well. In contrast, fifth link116of bike100is coupled to front triangle102at a position that is vertically higher than its rear joint122, and upward motion of the rear wheel causes the rear end of link116to pivot downward.

In some examples, as shock absorber218is compressed from a fully uncompressed state to a fully compressed state a braking anti-rise value may have a period of increase followed by a period of decrease. This may generally be the opposite behavior of the braking anti-rise value of bicycle100. However, an acceleration anti-squat value for bicycle200may generally decrease with compression of the shock absorber, a behavior that may be substantially similar to bicycle100. Again, the difference between bicycle200and bicycle100illustrates how, in six-bar rear suspension systems having five movable links, the braking anti-rise value may be decoupled from the acceleration anti-rise value. In contrast, in four-bar rear suspension systems having three movable links, the braking anti-rise value is often coupled to the acceleration anti-rise value.

FIGS. 8 and 9are schematic depictions of another illustrative rear suspension bicycle300, which is similar to bicycles100and200, and also comprises an example of a Stephenson III topology. Similar components of bicycle300are named and numbered as their substantially similar counterparts in bicycle100. For example, front triangle302is similar to front triangle102, and is joined to rear wheel304by rear triangle306, corresponding to rear wheel104and rear triangle106. Other than as described below, correspondingly numbered components are substantially as described above.FIG. 8shows bicycle300with a shock absorber318in a substantially uncompressed state andFIG. 9shows bicycle300with shock absorber318in a substantially fully compressed state.

Bicycle300may differ from bicycle100and bicycle200in the exact disposition and orientation of the first through fifth links, here referred to as links308,310,312,314, and316. For example, the lower front joint of link310is generally configured to move into and out of the space between the forward joints of the first and fifth links. In contrast, for example, joint120is disposed rearward of joints128and130at all times. However, upper front joint122of link110in bicycle100does travel into and out of the space between joints128and130. Accordingly, this portion of the linkage of bicycle300may, in some respects, be regarded as an upside down version of the corresponding portion of the linkage of bicycle100. As with bicycle100, second link310may be described as a chain stay link, because it is in a frame position typical of a bicycle chain stay, and third link312may be described as a seat stay link, because it is in a frame position typical of a bicycle seat stay.

With continuing reference toFIGS. 8-9, an overview of the six links and seven joints of this six-bar linkage will now be provided. As described above, any or all of the pivotal connections may include suitable bearings, collets, and/or the like. In this example, second link310and the frame of front triangle302are each ternary links, i.e., having three pivoting joints connecting each of them to other links of the linkage. Specifically, second link310is coupled at a front end to first link308by a first rotating joint320and to fifth link316by a second rotating joint322, and further coupled at a rear end to third link312by a third rotating joint324. Front triangle302is coupled to fourth link314by a fourth rotating joint326, to fifth link316by a fifth rotating joint328, and to first link308by a sixth rotating joint330.

Accordingly, the four binary links are connected in the linkage as follows. Binary link308is coupled at a front end to the front triangle by joint330and at a rear end to the second link by joint320. Binary link316is coupled at a front end to the front triangle by joint328and at a rear end to the second link by joint322. Finally, binary link312is joined to binary link314by a seventh rotating joint332, and to ternary link310by joint324.

Due to the spacing of joints320and322, second link310has a generally triangular shape, as shown inFIGS. 8-9. However, link310may be shaped in any suitable manner that comports with the triangular relationship between its three joints. For example, link310may have a solid triangular shape, may be formed of three legs or members arranged in a triangle, or may include fewer or more legs arranged in a rigid formation facilitating the spacing of joints320,322, and324. For simplicity, link310is shown as a rigid, triangular structure.

In addition to the links and joints that comprise the overall six-bar linkage, other connections and features may be present to facilitate use of the linkage in a rear suspension system. For example, third link312is a binary link, but includes an additional rotational joint334at axis AWwhere rear wheel304is coupled to the suspension. Joint334is offset from third rotating joint324, e.g., to avoid interference between the wheel axle/hub and the linkage. Accordingly, third link312is also shown as a rigid triangular arrangement, but may include any suitable shape or number of structural members configured to maintain the relationship between the rotating joints. Additionally, fourth link314extends forward of fourth rotating joint326, creating a pivoting rocker arm having its fulcrum at joint326. At the forward end of the rocker arm, another rotating joint336couples link314to shock absorber318, thereby providing a mechanical dampener for the linkage by affecting rotation of link314.

As the shock absorber moves from the substantially uncompressed state (FIG. 8) to the substantially compressed state (FIG. 9), all of the movable links rotate in a CW direction with respect to their respective forward joints except first link308, which moves in a CCW direction. Upward motion of the rear wheel causes second link310to pivot upward, pulling its forward end rearward and pulling joint320of first link308to the rear as well. This is analogous to the movement of fifth link116of bike100, which is configured such that upward motion of the rear wheel causes the rear end of link116to pivot downward.

In some examples, as shock absorber318is compressed from a fully uncompressed state to a fully compressed state a braking anti-rise value may generally increase. This may generally be different behavior of the braking anti-rise values of bicycle100and/or bicycle200. However, an acceleration anti-squat value for bicycle300may generally decrease with compression of the shock absorber, a behavior that may be substantially similar to bicycle100.

FIGS. 10 and 11show respective charts of dCSL and leverage ratio vs. vertical wheel travel corresponding to the suspension of bicycle300.

FIGS. 12 and 13are schematic depictions of a rear suspension bicycle400, which is similar to bicycles100,200, and300, but which comprises a Stephenson II topology, as described below. Similar components of bicycle400are named and numbered as their substantially similar counterparts in bicycle100. For example, front triangle402is similar to front triangle102, and is joined to rear wheel404by rear triangle406, corresponding to rear wheel104and rear triangle106. Other than as described below, correspondingly numbered components are substantially as described above.FIG. 12shows bicycle400with a shock absorber418in a substantially uncompressed state andFIG. 13shows bicycle400with shock absorber418in a substantially fully compressed state.

Bicycle400may differ from bicycles100,200, and300in the exact disposition and orientation of the first through fifth links, here referred to as links408,410,412,414,416. Additionally, bicycle400may further differ with respect to which links are coupled to which. In particular, rather than being joined to front triangle402, fifth link416shares a floating, rotating joint428with fourth link414. Accordingly, links410and414are the ternary links in this example, as opposed to link410and the bike frame, and the overall topology is that of a Stephenson II chain as opposed to a Stephenson III chain. As with bicycle100, second link410may be described as a chain stay link, because it is in a frame position typical of a bicycle chain stay, and third link412may be described as a seat stay link, because it is in a frame position typical of a bicycle seat stay.

With continuing reference toFIGS. 12-13, an overview of the six links and seven joints of this six-bar linkage will now be provided. As described above, any or all of the pivotal connections may include suitable bearings, collets, and/or the like. In this example, second link410and fourth link414are each ternary links, i.e., having three pivoting joints connecting each of them to other links of the linkage. Specifically, second link410is coupled at a front end to first link408by a first rotating joint420and to fifth link416by a second rotating joint422, and further coupled at a rear end to third link412by a third rotating joint424. Fourth link414is coupled to front triangle402by a fourth rotating joint426, to third link412by a seventh rotating joint432, and to fifth link416by joint428as described above.

Accordingly, the four binary links are connected in the linkage as follows. Binary link408is coupled at a front end to the front triangle by joint430and at a rear end to the second link by joint420. Binary link416, which is longer than corresponding links116,216,316, is coupled at an upper/front end to the rocker arm (rearward of the main fulcrum) by joint428and at a lower/rear end to the second link by joint422. Finally, binary link412is joined to ternary link414by a seventh rotating joint432, and to ternary link410by joint424.

Due to the spacing of joints420and422, second link410has a generally triangular shape, as shown inFIGS. 12-13. However, link410may be shaped in any suitable manner that comports with the triangular relationship between its three joints. For example, link410may have a solid triangular shape, may be formed of three legs or members arranged in a triangle, or may include fewer or more legs arranged in a rigid formation facilitating the spacing of joints420,422, and424. For simplicity, link410is shown as a rigid, triangular structure.

In addition to the links and joints that comprise the overall six-bar linkage, other connections and features may be present to facilitate use of the linkage in a rear suspension system. For example, third link412is a binary link, but includes an additional rotational joint434at axis AWwhere rear wheel404is coupled to the suspension. Joint434is offset from third rotating joint424, e.g., to avoid interference between the wheel axle/hub and the linkage. Accordingly, third link412is also shown as a rigid triangular arrangement, but may include any suitable shape or number of structural members configured to maintain the relationship between the rotating joints. Additionally, fourth link414extends forward of fourth rotating joint426, creating a pivoting rocker arm having its fulcrum at joint426. At the forward end of the rocker arm, another rotating joint436couples link414to shock absorber418, thereby providing a mechanical dampener for the linkage by affecting rotation of link414.

As the shock absorber moves from the substantially uncompressed state (FIG. 12) to the substantially compressed state (FIG. 13), all five of the movable links rotate in a CW direction with respect to their respective forward joints, and may translate in a generally vertical direction. In some examples, as shock absorber418is compressed from a fully uncompressed state to a fully compressed state a braking anti-rise value may have a period of decrease followed by a period of increase. This may qualitatively be similar to behavior of the braking anti-rise values of bicycle100and qualitatively different from the behavior of the braking anti-rise values of bicycle200and/or bicycle300. However, an acceleration anti-squat value for bicycle400may generally decrease with compression of the shock absorber, a behavior that may be substantially similar to bicycle100.

FIG. 14is a schematic depiction of another rear suspension bicycle500, which is similar to bicycles100,200,300,400. Similar components of bicycle500are named and numbered as their substantially similar counterparts in bicycle100. For example, front triangle502is similar to front triangle102, and is joined to rear wheel504by rear triangle506, corresponding to rear wheel104and rear triangle106. Other than as described below, correspondingly numbered components are substantially as described above.FIG. 14shows bicycle500with a shock absorber518in a substantially uncompressed state.

Bicycle500may differ from bicycle100in the exact disposition and orientation of the first through fifth links, referred to here as links508,510,512,514,516, and shock absorber518. In particular, fourth link514may have a different configuration than fourth link114and shock absorber518may have a different disposition and orientation than shock absorber118. Additionally, third link512may have a greater length than third link112as a rotating joint532between third link512and fourth link514may be farther forward than rotating joint132. As with bicycle100, second link510may be described as a chain stay link, because it is in a frame position typical of a bicycle chain stay, and third link512may be described as a seat stay link, because it is in a frame position typical of a bicycle seat stay.

In this example, fourth link514is coupled to a top tube546of front triangle502and pivots or rocks on an upper rotating joint526. In contrast, fourth link114is coupled to front triangle102at rotating joint126on seat tube142. Shock absorber518is coupled to fourth link514at a rotating joint536, and to top tube546at a rotating joint538. In contrast, shock absorber118is coupled to the front triangle at joint138proximate bottom bracket shell140and/or down tube144.

As shock absorber518moves from the substantially uncompressed state shown inFIG. 14to a substantially compressed state, the rocker arm formed by fourth link514rotates in a CCW direction. In contrast, fourth link114rotates in a CW direction as shock absorber118is compressed.

It will be appreciated that the first, second, third, and fifth links of bicycle500are most similar to the first, second, third, and fifth links of bicycle100, respectively, and that the primary differences between bicycles500and100are (a) the CW rotation of the fourth link and (b) the shock absorber being coupled to the top tube. It will also be appreciated that any or all of bicycles200,300, and400may also be reconfigured to include a clockwise rotating fourth link and a shock absorber coupled to the top tube as shown inFIG. 14.

D. Additional Examples and Illustrative Combinations

a front triangle; and

a first linkage member, a second linkage member, a third linkage member, a fourth linkage member, a fifth linkage member, and a shock absorber;

wherein the first linkage member has a pivotal connection with the front triangle and a pivotal connection with the second linkage member;

wherein the second linkage member has a pivotal connection with the first linkage member, a pivotal connection with the third linkage member, and a pivotal connection with the fifth linkage member;

wherein the third linkage member has a pivotal connection with the second linkage member, a pivotal connection with a rear wheel rotation axis, and a pivotal connection with the fourth linkage member;

wherein the fourth linkage member has a pivotal connection with the third linkage member, a pivotal connection with the front triangle, and a pivotal connection with the shock absorber;

wherein the fifth linkage member has a pivotal connection with the second linkage member; and

wherein the shock absorber has a pivotal connection with the fourth linkage member and a pivotal connection with the front triangle, and is configured to control movement of the first through fifth linkage members relative to the front triangle.

A2. The rear suspension bicycle of paragraph A1, wherein the fifth linkage member has a pivotal connection with the front triangle.

A3. The rear suspension bicycle of paragraph A1, wherein the fifth linkage member has a pivotal connection with the fourth linkage member.

A4. The rear suspension bicycle of paragraph A1, wherein the front triangle includes a seat tube, the shock absorber is disposed in front of the seat tube, and the shock absorber has a substantially vertical orientation.

A5. The rear suspension bicycle of paragraph A1, wherein the first through fifth linkage members, along with the shock absorber, compose a system having one degree of freedom.

A6. The rear suspension bicycle of paragraph A1, wherein the first, second, third, fourth, and fifth linkage members and the shock absorber are configured so that the rear wheel rotation axis traces a non-circular arc when the shock absorber moves between an uncompressed state and a compressed state, and wherein an center of curvature for the non-circular arc moves forward as the shock absorber is compressed.

A7. The rear suspension bicycle of paragraph A1, wherein a shock rate rises generally linearly with respect to vertical wheel travel distance as the shock absorber is compressed from a fully uncompressed state to a fully compressed state.

A8. The rear suspension bicycle of paragraph A7, wherein a rate of change of chainstay length with respect to vertical wheel travel distance is relatively high when the shock absorber is at sag and relatively low when the shock absorber is more deeply compressed.

A9. The rear suspension bicycle of paragraph A8, wherein a change in the shock rate with respect to vertical wheel travel distance is independent of a rate of change of a chainstay length with respect to vertical wheel travel distance as the shock absorber is compressed.

A10. The rear suspension bicycle of paragraph A1, wherein an instant center moves rearward from an initial location in front of a pedaling axis as the shock absorber is compressed.

A11. The rear suspension bicycle of paragraph A1, wherein the first through fifth linkage members define a plurality of instant centers.

A12. The rear suspension bicycle of paragraph A1, wherein an acceleration anti-squat value decreases as the shock absorber is compressed.

A13. The rear suspension bicycle of paragraph A12, wherein the acceleration anti-squat value decreases from a value substantially equal to 100% to a value of substantially equal to zero as the shock absorber is compressed from a fully uncompressed state to a fully compressed state.

A14. The rear suspension bicycle of paragraph A1, wherein a braking anti-rise value has a period of decrease followed by a period of increase as the shock absorber is compressed from a fully uncompressed state to a fully compressed state.

A15. The rear suspension bicycle of paragraph A1, wherein a braking anti-rise value has a period of increase followed by a period of decrease as the shock absorber is compressed from a fully uncompressed state to a fully compressed state.

A16. The rear suspension bicycle of paragraph A1, wherein a braking anti-rise value generally increases as the shock absorber is compressed from a fully uncompressed state to a fully compressed state.

A17. The rear suspension bicycle of paragraph A1, wherein an acceleration anti-squat value is decoupled from a braking anti-rise value as the shock absorber is compressed.

a frame including a front triangle; and

a rear suspension system having a shock absorber and coupling the front triangle to a rear wheel, the rear suspension in combination with the front triangle comprising a six-bar linkage having a Stephenson topology.

B1. The bicycle of B0, wherein the six-bar linkage has a Stephenson III topology.

B2. The bicycle of B0, wherein the six-bar linkage has a Stephenson II topology.

a frame including a rigid front triangle; and

a rear suspension system having a shock absorber and coupling the front triangle to a rear wheel, the rear suspension in combination with the front triangle comprising a six-bar linkage having exactly two ternary links separated from each other by at least one binary link, such that the two ternary links have no joints in common;

wherein a first ternary link of the two ternary links comprises a chain stay link.

C1. The bicycle of C0, wherein a second ternary link of the two ternary links comprises a portion of the front triangle.

C2. The bicycle of C1, wherein the portion of the front triangle is a seat tube.

C2A. The bicycle of C1, wherein the portion of the front triangle is a top tube.

C3. The bicycle of C0, wherein the chain stay link is coupled at a rear end portion to a seat stay link by a first rotating joint, and coupled at a front end portion to a pair of binary links by a second rotating joint and a third rotating joint, respectively.

C4. The bicycle of C3, wherein the pair of binary links connect the chain stay link to a second ternary link.

C5. The bicycle of C4, wherein the second ternary link comprises a portion of the front triangle.

C6. The bicycle of C3, wherein one link of the pair of binary links connects the chain stay link to the front triangle and the other link of the pair of binary links connects the chain stay link to a second ternary link.

C7. The bicycle of C0, wherein a second ternary link of the two ternary links comprises a rocker arm coupling a seat stay link to the front triangle.

C8. The bicycle of C7, wherein the rocker arm is coupled to the front triangle by a rotating joint and by the shock absorber.

C9. The bicycle of C0, wherein the chain stay link is coupled to the second ternary link by a total of no more than two binary links.

C10. The bicycle of C9, wherein one of the no more than two binary links is a seat stay link.

C11. The bicycle of C0, wherein the shock absorber is coupled between a down tube of the front triangle and one of the links of the six-bar linkage.

C12. The bicycle of C11, wherein the one of the links comprises a rocker arm rotationally joined to a seat tube of the front triangle.

C13. The bicycle of C0, wherein the six-bar linkage comprises a seat stay link coupled to the chain stay link by a first rotating joint, and the rear tire is coupled to the seat stay link by a second rotating joint that is offset from the first rotating joint by a selected distance.

C14. The bicycle of C13, wherein the second rotating joint is disposed proximate and rearward of the first rotating joint.

C15. The bicycle of C13, wherein the selected distance is at most approximately 200 mm.

a bicycle frame; and

a rear suspension system coupling the bicycle frame to a rear wheel, the rear suspension system in combination with the frame comprising a six-bar linkage, the six-bar linkage including:

a chain stay link comprising a first ternary link coupled at a front end portion by a first joint to a first binary link and by a second joint to a second binary link, and coupled at a rear end portion by a third joint to a seat stay link comprising a third binary link;

a fourth binary link coupled by a fourth joint to the seat stay link;

wherein the first binary link is coupled to the bicycle frame by a fifth joint, the second binary link is coupled to the bicycle frame by a sixth joint, and the fourth binary link is coupled to the bicycle frame by a seventh joint, such that the bicycle frame is a second ternary link of the six-bar linkage; and

a shock absorber coupling the fourth binary link to the bicycle frame.

D1. The bicycle of D0, wherein the fourth binary link extends forward of the seventh joint, such that the fourth binary link comprises a rocker arm coupled on one side of the seventh joint to the seat stay link and on the other side of the seventh joint to the shock absorber.

D2. The bicycle of D1, wherein the shock absorber is connected between the fourth binary link and a down tube of the bicycle frame.

D3. The bicycle of D0, wherein the rear wheel is rotatably coupled to the seat stay link proximate the third joint.

D4. The bicycle of D3, wherein an axle of the rear wheel is spaced less than approximately 200 mm from the third joint.

D5. The bicycle of D0, wherein the seventh joint is on a top tube of the bicycle frame.

D6. The bicycle of D0, wherein the seventh joint is on a seat tube of the bicycle frame.

D7. The bicycle of D6, wherein the shock absorber has a generally vertical orientation.

D8. The bicycle of D6, wherein the shock absorber is generally parallel and adjacent to the seat tube.

D9. The bicycle of D0, wherein the first and second joints of the chain stay link are spaced farther apart from each other than are the fifth and sixth joints.

D10. The bicycle of D0, wherein the first and second joints of the chain stay link are spaced more closely together than are the fifth and sixth joints.

D11. The bicycle of D0, wherein the second joint of the chain stay link is disposed generally between the fifth joint and the sixth joint.

D12. The bicycle of D0, wherein the suspension is transitionable between an uncompressed configuration, in which the shock absorber is uncompressed and the four binary links and the chain stay link are in respective first positions, and a compressed configuration, in which the shock absorber is compressed and the four binary links and the chain stay link are in respective second positions, each of the second positions being oriented in a clockwise direction relative to the respective first positions when viewed from a right side of the bicycle.

a bicycle frame; and

a rear suspension system coupling the bicycle frame to a rear wheel, the rear suspension system in combination with the frame comprising a six-bar linkage, the six-bar linkage including:

a chain stay link comprising a first ternary link coupled at a front end portion by a first joint to a first binary link and by a second joint to a second binary link, and coupled at a rear end portion by a third joint to a seat stay link comprising a third binary link;

a rocker arm coupled by a fourth joint to the seat stay link;

wherein the first binary link is coupled to the rocker arm by a fifth joint, the second binary link is coupled to the bicycle frame by a sixth joint, and the rocker arm is coupled to the bicycle frame by a seventh joint, such that the rocker arm comprises a second ternary link of the six-bar linkage and the bicycle frame comprises a fourth binary link of the six-bar linkage; and

a shock absorber coupling the fourth binary link to the bicycle frame.

E1. The bicycle of E0, wherein the seventh joint defines a fulcrum of the rocker arm, the rocker arm extending forward of the fulcrum.

E2. The bicycle of E1, wherein the rocker arm is coupled on a rear side of the fulcrum to the seat stay link and to the chain stay link, and the rocker arm is coupled on a forward side of the fulcrum to the shock absorber.

E3. The bicycle of E2, wherein the shock absorber is connected between the fourth binary link and a down tube of the bicycle frame.

E4. The bicycle of E0, wherein the rear wheel is rotatably coupled to the seat stay link proximate the third joint.

E5. The bicycle of E4, wherein an axle of the rear wheel is spaced less than approximately 200 mm from the third joint.

E6. The bicycle of E0, wherein the seventh joint is on a top tube of the bicycle frame.

E7. The bicycle of E0, wherein the seventh joint is on a seat tube of the bicycle frame.

E8. The bicycle of E7, wherein the shock absorber has a generally vertical orientation.

E9. The bicycle of E7, wherein the shock absorber is generally parallel and adjacent to the seat tube.

E10. The bicycle of E0, wherein the first and second joints of the chain stay link are spaced more closely together than are the fifth and sixth joints.

E11. The bicycle of E0, wherein the second joint of the chain stay link is disposed generally lower than the sixth joint.

E12. The bicycle of E0, wherein the suspension is transitionable between an uncompressed configuration, in which the shock absorber is uncompressed and the four binary links and the chain stay link are in respective first positions, and a compressed configuration, in which the shock absorber is compressed and the four binary links and the chain stay link are in respective second positions, each of the second positions being oriented in a clockwise direction relative to the respective first positions when viewed from a right side of the bicycle.

The different embodiments of the bicycle rear suspension systems described herein provide several advantages over known solutions for providing rear suspension to a bicycle. For example, the illustrative embodiments of rear suspension bicycles described herein allow pedaling-related variables to be decoupled from shock absorber-related variables. Additionally, and among other benefits, illustrative embodiments of the rear suspension bicycles described herein allow for a linearly or monotonically rising shock rate. Additionally, and among other benefits, illustrative embodiments of the rear suspension bicycles described herein allow a change in the shock rate with respect to vertical wheel travel distance to be independent of a rate of change in chainstay length with respect to vertical wheel travel distance as the shock absorber is compressed. Additionally, and among other benefits, illustrative embodiments of the rear suspension bicycles described herein allow for an empty space between the top tube and the down tube of the front triangle for accommodating other bicycle equipment. No known system or device can perform these functions. However, not all embodiments described herein provide the same advantages or the same degree of advantage.

CONCLUSION