Patent Description:
<CIT> discloses a bicycle frame according to the preamble of claim <NUM>.

A bicycle frame according to the invention includes a top tube that connects to a head tube at a front portion of the bicycle frame. The bicycle frame also includes a first seat stay that connects to the top tube at a first point of intersection and a second seat stay that connects to the top tube at a second point of intersection such that a back portion of the top tube extends beyond the first point of intersection and the second point of intersection so that the top tube is a cantilever. The bicycle frame also includes a seatmast sized to receive a seatpost. The seatmast extends from the back portion of the top tube that forms the cantilever.

According to the invention, the bicycle frame also includes a down tube that extends from the head tube to a bottom bracket and a seat tube that extends from the bottom bracket. The bicycle frame also includes a first support that extends from the seat tube to the first seat stay and a second support that extends from the seat tube to the second seat stay. The bicycle frame also includes an opening formed under the top tube and under the seat mast and configured to convey turbulent air from underneath the top tube to behind the bicycle frame. According to the invention, at least a portion of the opening is formed by a bottom portion of the top tube, at least a portion of the opening is formed by the first seat stay and the second seat stay, and at least a portion of the opening is formed by the first support and the second support.

The bicycle frame can also include a first chain stay that extends from the bottom bracket to the first seat stay and a second chain stay that extends from the bottom bracket to the second seat stay. In another embodiment, the bicycle frame includes a plurality of slots in a rear-facing portion of the seatmast. The seatpost can be mounted in the seatmast, and the seatpost includes a cavity configured to receive a seatpost securing assembly. The seatpost securing assembly includes a compression bolt, and the seatpost can include a plurality of openings sized to receive the compression bolt. In an illustrative embodiment, the plurality of openings are adjacent to the cavity of the seatpost that includes the seatpost securing assembly. The plurality of openings are also aligned with the plurality of slots in the rear-facing portion of the seatmast.

The seatpost securing assembly can include a cam lever and a wedge. The cam lever is configured to press the wedge against an interior surface of the seatmast to secure the seatpost to the seatmast. A retaining clip of the seatpost securing assembly is configured to secure the wedge to the cam lever. In another embodiment, the cam lever includes a first opening configured to receive a barrel nut, where the barrel nut includes a threaded opening configured to receive the compression bolt. In an illustrative embodiment, responsive to being rotated, the compression bolt pushes the barrel nut and at least a portion of the cam lever toward the wedge and causes the wedge to contact the interior surface of the seatmast. The cam lever can also include a second opening configured to receive the barrel nut.

In another illustrative embodiment, the cam lever controls a height of the seatpost based at least in part on an orientation of the cam lever within the seatpost. The cam lever includes a first portion and a second portion. In a first orientation of the cam lever the first portion is positioned toward a top of the cavity in the seatpost and the second portion is positioned toward a bottom of the cavity in the seatpost. In a second orientation of the cam lever the first portion is positioned toward a bottom of the cavity in the seatpost and the second portion is positioned toward a top of the cavity in the seatpost.

Other principal features and advantages of the invention will become apparent to those skilled in the art upon review of the following drawings, the detailed description, and the appended claims.

Illustrative embodiments will hereafter be described with reference to the accompanying drawings, wherein like numerals denote like elements. The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings.

Described herein is a bicycle frame with a cantilevered seatpost that is designed to reduce resistance due to airflow, improve rider comfort, and lower the overall weight of the bicycle frame. More specifically, a seatmast of the bicycle frame, which is designed to receive the seatpost, is formed as a cantilever by the seat stays and the top tube of the bicycle frame. This cantilever design allows for inclusion of an opening formed between the seat tube (or supports that extend from the seat tube), the seat stays, and the top tube of the bicycle frame. As discussed in more detail below, this opening acts to divert turbulent air through the bicycle frame to reduce overall air resistance for the rider. In other words, the opening acts to energize the wake typically seen behind the seat stay/seatmast region of the bicycle. Also described herein is a seatpost securing assembly that is positioned within the seatmast and used to secure and adjust a seatpost of the bicycle.

<FIG> depicts a bicycle <NUM> with a frame <NUM> that includes a cantilevered seatmast <NUM> in accordance with a first illustrative embodiment. <FIG> depicts a bicycle frame <NUM> that includes a cantilevered seatmast <NUM> in accordance with a second illustrative embodiment. Referring to <FIG>, the bicycle <NUM> includes a saddle assembly <NUM> and handlebars <NUM> attached to the frame <NUM>. A saddle (or seat) <NUM> is part of the saddle assembly <NUM>. A saddle clamp <NUM> is engaged with an underside <NUM> of saddle assembly <NUM> and cooperates with a seatpost <NUM> that slidably engages the seatmast <NUM> of frame <NUM>. As such, the position of the saddle <NUM> is adjustable relative to the frame <NUM> to accommodate different riders. A top tube <NUM> and a down tube <NUM> of the frame <NUM> are connected to a seat (or saddle) tube <NUM> and to a head tube <NUM> of the frame <NUM>.

Handlebars <NUM> of the bicycle <NUM> are connected to a steerer tube <NUM> that passes through head tube <NUM> and engages a fork crown <NUM>. A pair of fork blades <NUM>, <NUM> extend from generally opposite ends of fork crown <NUM> and are constructed to support a front wheel assembly <NUM> at an end thereof or fork tip <NUM>. The fork blades <NUM>, <NUM> can be part of a suspension bicycle fork or a rigid bicycle fork. As also shown in <FIG>, fork tips <NUM> engage generally opposite sides of an axle <NUM> that is constructed to engage a hub <NUM> of front wheel assembly <NUM>. A number of spokes <NUM> extend from hub <NUM> to a rim <NUM> of front wheel assembly <NUM>. A tire <NUM> is engaged with rim <NUM> such that rotation of tire <NUM>, relative to forks <NUM>, rotates rim <NUM> and hub <NUM>.

A rear wheel assembly <NUM> is positioned generally concentrically about a rear axle <NUM>. A seat stay <NUM> and a chain stay <NUM> offset rear axle <NUM> from a crankset <NUM>. The crankset <NUM> includes pedals <NUM> that are operationally connected to a flexible drive such as a chain <NUM> via a chain ring or sprocket <NUM>. Rotation of the chain <NUM> communicates a drive force to a rear section <NUM> of the bicycle <NUM> having a gear cluster <NUM> positioned thereat. The gear cluster <NUM> is generally concentrically orientated with respect to the rear axle <NUM> and includes a number of variable diameter gears. The gear cluster <NUM> is operationally connected to a hub <NUM> associated with a rear tire <NUM> of rear wheel assembly <NUM>. A number of spokes <NUM> extend radially between the hub <NUM> and a rim <NUM> that supports tire <NUM> of rear wheel assembly <NUM>. As is commonly understood, rider operation of the pedals <NUM> drives the chain <NUM> thereby driving the rear tire <NUM> which in turn propels the bicycle <NUM>.

<FIG> depict various views of the bicycle frame with a cantilevered seatmast. Specifically, <FIG> is a first side view of a bicycle frame <NUM> with a cantilevered seatmast <NUM> in accordance with an illustrative embodiment. <FIG> is a second side view of the bicycle frame <NUM> with the cantilevered seatmast <NUM> in accordance with an illustrative embodiment. <FIG> is a front view of the bicycle frame <NUM> with the cantilevered seatmast <NUM> in accordance with an illustrative embodiment. <FIG> is a rear view of the bicycle frame <NUM> with the cantilevered seatmast <NUM> in accordance with an illustrative embodiment. <FIG> is a bottom view of the bicycle frame <NUM> with the cantilevered seatmast <NUM> in accordance with an illustrative embodiment. <FIG> is a top view of the bicycle frame <NUM> with the cantilevered seatmast <NUM> in accordance with an illustrative embodiment.

The bicycle frame <NUM> also includes a top tube <NUM> from which the cantilevered seatmast <NUM> extends. The top tube <NUM> connects to a head tube <NUM> and to a down tube <NUM>. The down tube <NUM> extends to a bottom bracket <NUM>, which is connected to a seat tube <NUM> and a pair of chain stays <NUM>. The pair of chain stays <NUM> connect to a pair of seat stays <NUM>. As shown, the seatmast <NUM> extends in an upward direction (i.e., relative to a ground surface on which the bicycle frame <NUM> is positioned upright) from the top tube <NUM>. As also shown, a rear portion <NUM> of the top tube <NUM> extends to the rear of the bicycle frame, beyond the points of intersection between the seat stays <NUM> and the top tube <NUM> such that the top tube <NUM> acts as a cantilever. As a result, the seatmast <NUM> extends upward from the top tube <NUM> at a location on the top tube <NUM> that is to the rear of the points of intersection between the top tube <NUM> and the seat stays <NUM>.

As discussed in more detail below, the seatmast is designed to receive a seatpost (or saddle post) that mounts within the female cavity formed by the seatmast <NUM>. As a result, due to the cantilever configuration of the seatmast, the seat (or saddle) of the bicycle and the rider's weight are positioned on the cantilevered portion of the top tube <NUM> (i.e., the portion of the top tube that extends rearward from the points of intersection between the top tube and the seat stays). As the bicycle is ridden over bumps and other terrain, the mass of the rider pushing down on the cantilevered portion of the top tube <NUM> creates additional flex in the bicycle frame, and this added compliance acts as a built-in shock absorption system that improves rider comfort as compared to a traditional bicycle frame.

As shown in <FIG>, the seat stays <NUM>, the seat tube <NUM>, and the top tube <NUM> meet to form an opening <NUM>. More specifically, in the depicted embodiment, a first support <NUM> and a second support <NUM> extend from the seat tube <NUM> to the seat stays <NUM> to form a portion of the opening. The first support <NUM> connects to a first of the seat stays <NUM> and the second support <NUM> connects to a second of the seat stays <NUM>. As a result a circumference of the opening <NUM> is formed in part by an inward facing portion of a first of the seat stays <NUM>, a bottom (or downward facing) portion of the top tube <NUM>, an inward facing portion of a second of the seat stays <NUM>, an upper portion of the first support <NUM>, and an upper portion of the second support <NUM>.

The proposed bicycle frame configuration also increases the torsional rigidity of the frame as compared to traditional frames. Specifically, the more forward point of intersection between seat stays and the top tube that forms the cantilever results in a bicycle frame that is less likely to twist in response to applied pressure or impact. This increases the overall torsional rigidity of the bicycle frame, which makes it more robust. The specific configuration of the bicycle frame also reduces the amount of material used, and thus the overall weight, as compared to traditional bicycle frames. As one example, the seat tube <NUM> can be of shorter length because it connects to the seat stays <NUM> as opposed to directly connecting to the seatmast and/or top tube, as in traditional bicycle frames.

<FIG> is a rear perspective view of the bicycle frame <NUM> which more clearly shows the opening <NUM> formed below the seatmast <NUM> in accordance with an illustrative embodiment. In an illustrative embodiment, as the bicycle is ridden, turbulent air from the front triangle of the bicycle frame is conveyed toward and through the opening <NUM> to the rear of the bicycle frame such that the overall air resistance experienced by the rider is reduced. As the rider rides the bicycle, turbulent (i.e., high pressure) air is formed in and around the front triangle of the bicycle. The turbulent air forms as a result of air contacting the down tube, the head tube, the top tube, the handlebars, the rider's legs, etc. This high pressure turbulent air causes significant drag on the bicycle. Conversely, a low pressure (i.e., low turbulence) air zone or wake is formed behind the front triangle and the rider of the bicycle. The opening <NUM> formed by the present bicycle frame configuration acts as a conduit through which the turbulent air in the high pressure zone of the front triangle and the rider's legs is diverted to the rear of the bicycle and the rider into the low pressure zone. Removing this turbulent air from the front triangle of the bicycle frame reduces the friction/drag experienced by the bicycle and the rider and acts to energize (i.e., increase) the wake behind the seatmast region of the bicycle.

As discussed above, the seatmast includes a cavity that is sized to receive a seatpost, to which a saddle is mounted for the rider to sit on while cycling. Described below is a seatpost securing assembly which helps secure the seatpost within the seatmast, and which enables several different seatpost adjustment options for the rider. <FIG> is a close-up sectional view of a seatpost <NUM> mounted within the seatmast <NUM> in accordance with an illustrative embodiment. The seatpost <NUM> includes a clamp <NUM> configured to receive a saddle and a seatpost securing assembly <NUM> that is used to hold the seatpost <NUM> within the seatmast <NUM>. In the view of <FIG>, the seatmast <NUM> is illustrated as partially transparent such that the seatpost securing assembly <NUM> can be seen.

<FIG> is a cross-sectional view of the seatpost <NUM> included an exploded view of the seatpost securing assembly <NUM> in accordance with an illustrative embodiment. As shown the seatpost <NUM> includes a cavity <NUM> configured to receive the seatpost securing assembly <NUM>. The cavity <NUM> includes a pair of rounded indents configured to receive the seatpost securing assembly <NUM>. As shown, the cavity <NUM> is not enclosed. Rather, a frontmost portion of the cavity <NUM> is open such that the cavity <NUM> provides direct access to an interior of the seatmast in which the seatpost is to be positioned. The pair of rounded indents are positioned at a rearmost portion of the cavity <NUM>.

The seatpost securing assembly <NUM> includes a compression bolt <NUM>, a barrel nut <NUM>, a cam lever <NUM>, a retaining clip <NUM>, and a wedge <NUM>. In alternative implementations, the seatpost securing assembly <NUM> may include fewer, additional, and/or different components. In an illustrative embodiment, a rear-facing side of the seatmast <NUM> included one or more vertically-oriented elliptical slots (or openings) through which the compression bolt <NUM> is received. For example, the views of <FIG> and <FIG> depicts a slot <NUM> that receives the compression bolt <NUM>. Alternatively, instead of an elliptical (or ovular) slot, the rear-facing side of the seatmast <NUM> can include one or more circular openings, one or more square openings, etc. Insertion and use of the compression bolt <NUM> is described in more detail below.

The compression bolt <NUM> is threaded and designed to mate with a female threaded opening in the barrel nut <NUM>, and the barrel nut <NUM> is sized to fit within either of two openings in the cam lever <NUM>. Specifically, the cam lever <NUM> includes a first portion <NUM> (at the top of the cam lever <NUM> in the orientation of <FIG>) that includes a first opening <NUM> and a second portion <NUM> (at the bottom of the cam lever <NUM> in the orientation of <FIG>) that includes a second opening <NUM>. The cam lever <NUM> also includes a body <NUM> between the first portion <NUM> and the second portion <NUM> that is in the form a rounded bulge that is designed to press against the wedge <NUM>. In an illustrative embodiment, either the first opening <NUM> or the second opening <NUM> can receive the barrel nut <NUM>. As discussed in more detail below, the selection of which hole to place the barrel nut <NUM> into (in the cam lever <NUM>), along with the orientation of the cam lever <NUM> and the vertical length of the slot(s) in the seatmast, can be used to provide adjustment options for the height of the seatpost <NUM>. When the barrel nut <NUM> is seated in one of the first opening <NUM> or the second opening <NUM>, the female threaded opening located along the shaft of the barrel nut <NUM> is oriented to receive the compression bolt <NUM>.

As the compression bolt <NUM> is threaded into the barrel nut <NUM> (which is seated in an opening in the cam lever <NUM>), the cam lever <NUM> moves such that the wedge <NUM> is pressed against an interior surface of the seatmast into which the seatpost <NUM> is mounted. The retaining clip <NUM> is used to help ensure that the wedge <NUM> remains in contact with and secured to the cam lever <NUM>. <FIG> are cross-sectional partial views of an assembled seatpost securing assembly <NUM> depicting cam lever movement resulting from threading the compression bolt <NUM> into the barrel nut <NUM>.

Specifically, <FIG> depicts a first position of the seatpost securing assembly <NUM> in accordance with an illustrative embodiment. As the compression bolt <NUM> is threaded into the barrel nut <NUM>, the barrel nut <NUM> and hence the second portion <NUM> of the cam lever <NUM> is pushed toward the wedge <NUM> (i.e., toward a front of the seatpost). <FIG> depicts an initial position of the cam lever <NUM> relative to the wedge <NUM> as the compression bolt <NUM> begins to push the barrel nut <NUM> and the second portion <NUM> of the cam lever <NUM> forward. <FIG> depicts a second position of the seatpost securing assembly <NUM> in accordance with an illustrative embodiment. As the compression bolt <NUM> continues to be tightened, the body <NUM> of the cam lever <NUM> continues to press the wedge <NUM> up against an interior surface of the seatmast <NUM>. As the body <NUM> of the cam lever <NUM> presses against the wedge <NUM>, it can be seen in <FIG> (relative to <FIG>) that the first portion <NUM> of the cam lever <NUM> (i.e., the portion containing the second opening <NUM>) gains separation from an upper portion of the wedge <NUM>. <FIG> depicts a third position of the seatpost securing assembly <NUM> in accordance with an illustrative embodiment. It can be seen in <FIG> (relative to <FIG>) that the first portion <NUM> of the cam lever <NUM> (i.e., the portion containing the second opening <NUM>) gains more separation from the upper portion of the wedge <NUM> as the compression bolt <NUM> continues to be tightened. This configuration ensures that the seatpost <NUM> is securely mounted within the seatmast as a result of the friction between the wedge <NUM> and the interior surface of the seatmast <NUM>.

In an alternative embodiment, the threads of the compression bolt <NUM> and/or the barrel nut <NUM> can be reversed. In such an embodiment and referring to the configuration shown in <FIG>, threading the compression bolt <NUM> into the barrel nut <NUM> can cause the second portion <NUM> of the cam lever <NUM> to be drawn toward a rear of the seatmast <NUM>, which in turn causes the first portion <NUM> of the cam lever <NUM> to press against the upper portion of the wedge <NUM>.

In the orientation shown in <FIG>, the first portion <NUM> of the cam lever <NUM> and the first opening <NUM> are positioned toward the top of the seatpost securing assembly, and the second portion <NUM> of the cam lever <NUM> and the second opening <NUM> are positioned toward the bottom of the seatpost securing assembly. In an illustrative embodiment, the cam lever <NUM>, wedge <NUM>, barrel nut <NUM>, and clip <NUM> can be flipped (i.e., rotated <NUM> degrees) such that the first portion <NUM> of the cam lever is positioned toward the top of the seatpost and the second portion <NUM> is positioned toward the bottom of the seatpost. Such flipping of the cam lever <NUM> from a first orientation to a second orientation allows the rider to control the overall height of the seatpost relative to the top of the seatmast. In the embodiment shown, the seatpost also includes two openings, an upper opening <NUM> and a lower opening <NUM>, through which the compression bolt <NUM> can be inserted to provide different height options for the seatpost. As discussed herein, the use of dual slots in the seatpost allows the slots in the seatmast to be smaller as compared to traditional systems. In one alternative embodiment, a single opening in the seatpost <NUM> may be used. In another alternative embodiment, additional openings may be provided in the seatpost <NUM> to provide saddle height additional adjustment options. For example, the seatpost <NUM> may include <NUM> openings, <NUM> openings, <NUM> openings, etc..

<FIG> depicts a first orientation of the cam lever <NUM> in accordance with an illustrative embodiment. <FIG> depicts a second orientation (flipped) of the cam lever <NUM> in accordance with an illustrative embodiment. In the embodiment of <FIG>, the first portion <NUM> of the cam lever <NUM> is positioned at the top and the second portion <NUM> of the cam lever <NUM> is positioned at the bottom of the cavity <NUM> formed in the seatpost <NUM>. This is similar to the configuration shown in <FIG>. In the embodiment of <FIG>, the first portion <NUM> of the cam lever <NUM> is positioned at the bottom and the second portion <NUM> of the cam lever <NUM> is positioned at the top of the cavity <NUM> formed in the seatpost <NUM>. The cam lever <NUM> has thus been flipped (i.e., rotated <NUM> degrees) in the embodiment of <FIG>. In <FIG>, the compression bolt <NUM> is positioned in the lower opening <NUM> and in <FIG> the compression bolt <NUM> is positioned in the upper opening <NUM> of the seatpost <NUM>.

Additional height adjustment of the seatpost <NUM> can be performed by controlling the position (i.e., height) of the compression bolt <NUM> within the slot(s) formed in the rear side of the seatmast. <FIG> depicts the seatpost <NUM> mounted in a highest configuration in accordance with an illustrative embodiment. <FIG> depicts the seatpost <NUM> mounted in a lowest configuration in accordance with an illustrative embodiment. As shown, the seatpost <NUM> extends from a seatmast <NUM>, and a rear-facing portion of the seatmast <NUM> includes an upper slot <NUM> and a lower slot <NUM>, each of which is in the shape of a vertically-oriented ellipse/oval. In alternative embodiments, the seatmast <NUM> may include fewer or additional slots (e.g., <NUM>, <NUM>, <NUM>, <NUM>, etc.), and/or openings of a different shape such as circular, square, etc. The slots allow the rider or a bicycle mechanic to access the compression bolt <NUM> with a tool (e.g., M4 allen wrench or other tool) for easy removal and/or adjustment of the seatpost. Additionally, this slot design that involves the use of <NUM> separate slots with bicycle frame material (e.g., carbon, aluminum, etc.) in between the slots allows for a reduction of reinforcement to the frame since it allows for a shorter slot, and thus greater hoop strength for the seatmast. This benefit is achieved in part by the use of dual slots in the seatpost, which allows the slots in the seatmast to be smaller as compared to traditional systems.

In the embodiment of <FIG>, the compression bolt <NUM> of the seatpost securing assembly is positioned at a highest position in the upper slot <NUM> of the seatmast <NUM>. Additionally, the cam lever <NUM> is positioned such that the first portion <NUM> is on top and the second portion <NUM> is on the bottom, similar to the embodiment shown in <FIG>. Also in <FIG>, the compression bolt <NUM> is threaded into the lower opening <NUM>, which in turn maximizes the height of the seatpost <NUM>.

In the embodiment of <FIG>, the compression bolt <NUM> of the seatpost securing assembly is positioned in the lower slot <NUM> of the seatmast <NUM>. Additionally, the cam lever <NUM> is positioned such that the first portion <NUM> is on the bottom and the second portion <NUM> is on the top, similar to the embodiment shown in <FIG>. Also in <FIG>, the compression bolt <NUM> is threaded into the upper opening <NUM>, which in turn minimizes the height of the seatpost <NUM>. In addition to flipping the cam lever and wedge, intermediate height adjustments of the seatpost can be performed by adjusting the seatpost securing assembly within the slot(s) in the rear of the seatmast, by changing which opening in the seatpost receives the compression bolt, and/or by changing which opening in the cam lever receives the barrel nut.

The word "illustrative" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "illustrative" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Further, for the purposes of this disclosure and unless otherwise specified, "a" or "an" means "one or more".

Claim 1:
A bicycle frame comprising:
a top tube (<NUM>, <NUM>) that connects to a head tube (<NUM>, <NUM>) at a front portion of the bicycle frame;
a down tube (<NUM>, <NUM>) that extends from the head tube (<NUM>, <NUM>) to a bottom bracket (<NUM>);
a seat tube (<NUM>, <NUM>) that extends from the bottom bracket;
a first seat stay (<NUM>, <NUM>) that connects to the top tube at a first point of intersection and a second seat stay (<NUM>, <NUM>) that connects to the top tube at a second point of intersection such that a back portion of the top tube extends beyond the first point of intersection and the second point of intersection so that the top tube is a cantilever;
a seatmast (<NUM>, <NUM>, <NUM>, <NUM>) sized to receive a seatpost (<NUM>, <NUM>), wherein the seatmast extends from the back portion of the top tube that forms the cantilever; characterized by a first support (<NUM>) that extends from the seat tube (<NUM>, <NUM>) to the first seat stay (<NUM>, <NUM>) and a second support (<NUM>) that extends from the seat tube to the second seat stay (<NUM>, <NUM>); and
an opening (<NUM>) formed under the top tube (<NUM>, <NUM>) and under the seatmast (<NUM>, <NUM>, <NUM>, <NUM>) and configured to convey turbulent air from underneath the top tube to behind the bicycle frame, wherein at least a portion of the opening is formed by a bottom portion of the top tube, at least a portion of the opening is formed by the first seat stay (<NUM>, <NUM>) and the second seat stay (<NUM>, <NUM>), and at least a portion of the opening is formed by the first support (<NUM>) and the second support (<NUM>).