Cycle trainer having a load applying device

A roller 26 for applying a load to a tire 44 of a rear wheel as a drive wheel is rotatably supported by support frames 30 through a roller shaft 24. The support frames 30 are rotatable about a fixing shaft 28 penetrating their ends. A support portion 29 supporting the fixing shaft 28 is fixed to a load applying device stand 2 to be inserted in a rear frame 22. A coil spring 34 is provided between a fixing plate 32 fixed to the load applying device stand 2 and a transverse plate 31 of the support frames 30. A pedal clamp 38 to be engaged with the plate 31 in a state of the coil spring 34 being compressed is rotatably provided on the load applying device stand 2. When a load applying device is to be used, the position of the load applying device stand 2 is adjusted so that the roller 26 slightly contacts the rear wheel tire 44 with the pedal clamp 38 being engaged with the plate 31. Then, the pedal clamp 38 is disengaged therefrom and the roller 26 applies a predetermined contact force as a load to the rear wheel tire 44.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to cycle trainers and particularly to a cycle 
trainer by which training can be done indoors, simulating real outdoor 
riding. 
2. Description of the Background Art 
There have been developed various cycle trainers used for cycle training in 
a room, simulating real outdoor running, in which a bicycle not having a 
front wheel is fixed and the rear wheel of the bicycle is rotatably in 
contact with a rotating roller to which load is applied. 
FIG. 17 is a schematic side view of such a cycle trainer disclosed in U.S. 
Pat. No. 4,441,705, and FIG. 18 is a sectional view taken along the line 
XVIII--XVIII of FIG. 17. 
Referring to those figures, the structure and functions of the cycle 
trainer will be described. 
A bicycle from which the front wheel is removed is fixedly supported by a 
front frame 152 and a stay 156 by means of a front fork 16 and a bracket 
lug 154. The front frame 152 is connected to a support 150 which is a main 
body of the trainer, and a height adjusting portion 158 into which the 
stay 156 is inserted for adjustment of the height is attached to a central 
portion of the support 150. A stable setting member 151 in the form of a 
pipe perpendicular to the support 150, for stably setting the trainer is 
connected to an end of the support 150. A load applying device 1 on which 
a rear wheel 10 is mounted is attached to a portion of the support 150 
near the stable setting member 151 through an adjusting bolt-nut set 164. 
The load applying device 1 comprises a roller 26 having a high friction 
coefficient to be in contact with a tire 44 of the rear wheel 10, a 
rotating shaft 162 inserted integrally in the roller 26 and rotatably 
supported by a support frame 30, a fan 50 attached to an end of the 
rotating shaft 162, and an inertial wheel adjuster 166 attached to the 
other end of the rotating shaft 162. The fan 50 is covered with a casing 
51, which has an opening connected with an air tube 160 having a top end 
near a handle portion of the bicycle. 
When the trainer is to be used, the height of the stay 156 is adjusted by 
the height adjusting portion 158 according to the size of the bicycle to 
be fixed and the bracket lug 154 is attached to the stay 156. Then, the 
adjusting bolt-nut set 164 is adjusted to move the support frame 30 
forward or backward so that the tire 44 is in contact with the roller 26, 
and then the load applying device 1 is fixed by fastening the adjusting 
bolt-nut set 164. After the adjustment and fixation of the bicycle, the 
user rides on the bicycle and practices cycle training by means of pedals 
14 in the same manner as in real riding of a bicycle. The pedal movement 
rotates the rear wheel 10 and rotates the roller 26 through the tire 44. 
The rotation of the roller 26 rotates simultaneously the fan 50 and the 
inertial wheel adjuster 166 through the rotating shaft 162. The inertial 
wheel adjuster 166 serves to apply a riding resistance in real riding to 
the user and the inertial wheel can be replaced at any time with other 
inertial wheel of a different size or weight. The fan 50 serves to apply 
an air resistance in real riding to the user and it gives a resistance to 
the rotating shaft 162 according to rotation of the roller 26, that is, a 
real riding speed. A quantity of air generated by the rotation of the fan 
50 is made to blow from the front side to the user of the trainer through 
the air tube 160 so as to produce an effect as if in outdoor riding of a 
bicycle. 
In the above described conventional cycle trainer, it is difficult to 
precisely simulate a real riding resistance. 
More specifically, although the inertial wheel adjuster 166 and the fan 50 
are provided to simulate the riding resistance and the air resistance in 
real riding of a bicycle, those devices exhibit their functions only on 
the basis of accurate contact between the tire 44 and the roller 26. 
However, the adjustment of the contact depends on adjustment by using the 
height adjusting portion 158 and the adjusting bolt-nut set 164 and 
therefore accurate adjustment of contact force cannot be expected. Thus, 
the resistance applied to the rotating shaft 162 by means of the inertial 
wheel adjuster 166 and the fan 50 cannot be accurately transmitted to the 
crank of the pedals 14 through the roller 26 under the tire 44 and 
accurate stable workload cannot be given to the user in a satisfactory 
manner. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide a useful cycle trainer. 
Another object of the present invention is to provide a cycle trainer 
capable of accurately simulating real riding of a bicycle. 
A further object of the present invention is to provide a cycle trainer 
which is capable of accurately simulating power based on a rolling 
resistance in real riding. 
In order to accomplish the above described objects, a cycle trainer 
according to the present invention comprises: a rotatable roller; 
energizing means for constantly energizing the roller in a direction of 
contact with a drive wheel; movement blocking means to be engaged with the 
energizing means, for blocking movement of the roller toward the direction 
of the drive wheel; position adjusting means for adjusting the roller at a 
predetermined position with respect to the drive wheel while the movement 
of the roller is blocked by the movement blocking means; and disengaging 
means for disengaging the movement blocking means from the energizing 
means, the disengaging means being enabled to release the movement 
blocking means from the energizing means so that the roller is rotatably 
in contact with the drive wheel. 
In the cycle trainer thus structured, the roller is brought into contact 
with the drive wheel by the energizing means after it has been adjusted at 
the predetermined position with respect to the drive wheel and accordingly 
it is possible to assure a constantly accurate contact force between the 
drive wheel and the roller. 
The foregoing and other objects, features, aspects and advantages of the 
present invention will become more apparent from the following detailed 
description of the present invention when taken in conjunction with the 
accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
First, the concept and the theory of a cycle trainer according to the 
present invention will be described and then structure and operation of an 
embodiment of the present invention will be described. 
In the cycle trainer according to the present invention, a load which 
accurately simulates a riding resistance on a flat ground or a climbing 
resistance on a slope based on a rolling resistance and an air resistance 
in real riding is applied to a drive wheel of a bicycle attached to the 
cycle trainer so that the user can practice training indoors corresponding 
to that in real riding of a bicycle. 
In general, a total riding resistance (R) of a bicycle in real riding is 
expressed as follows. 
R=Rr+Ra+Rs 
Rr: rolling resistance 
Ra: air resistance 
Rs: climbing resistance on slope 
Practically, an acceleration resistance is further added but it is 
difficult to approximate a resistance for increasing inertia energy based 
on speed changes of the acceleration. 
The rolling resistance (Rr) is a resistance on a contact face between the 
bicycle and the ground and it is expressed as follows: 
Rr=W.times..mu.(kgf) 
W: weight of user + weight of bicycle (kgf) 
.mu.: rolling resistance coefficient of tire 
The air resistance (Ra) is a resistance caused by air with respect to the 
user and the bicycle at the time of riding and it is expressed as follows: 
Ra=Cd.times.A.times..rho.v.sup.2 /2 (kgf) 
Cd: resistance coefficient 
A: forward projected area of user and bicycle (m.sup.2) 
.rho.: air density (0.125kg..multidot..sup.-4 .multidot.S.sup.2) 
v: riding speed (v.multidot.s.sup.-1) 
Consequently, power P against riding resistance on a flat ground is 
expressed as follows: 
P =(Rr+Ra).times.g.times.v (watt) 
g: gravitational acceleration speed (9.multidot.8m.S.sup.-2) 
FIG. 13 is a graph showing a relation between the power P and a riding 
speed v. In this graph, the solid lines represent values of power against 
rolling resistance, power against air resistance and power against riding 
resistance on a flat ground, calculated by the above indicated equation on 
the assumptions as follows: a rolling resistance coefficient on a flat 
ground is .mu.=0.012; the total weight as an average value of a general 
sports type bicycle and a user is W=81.multidot.6kgf. (180 bf); a 
projected area in a forward inclined posture is A=0.36m.sup.2 ; and an air 
resistance coefficient in this posture is Cd=0.88. 
The dots represent measured values of the power based on rolling 
resistance of a roller; the dots o represent measured values of the power 
based on wind resistance; and the dots represent values obtained by 
addition of the measured values of the power based on windwill resistance 
to the measured values of the power based on rolling resistance. 
The total resistance (R) in running on a slope is expressed as follows: 
R=Rr+Ra 
Rr+Ra: riding resistance on flat ground 
Rs: climbing resistance 
Rs=W.times.sin .theta.(kgf) 
.theta.: angle of gradient of slope 
Therefore, power Ps in opposition to the climbing resistance is as follows: 
Ps=Rs.times.g.times.v (watt) 
FIG. 14 is a graph showing a relation between the power Ps and the riding 
speed v of the bicycle for each specified gradient. In this graph, the 
solid lines represent calculated values of power in opposition to climbing 
resistance with W=81.6 kgf. for the respective gradient angles. 
The dots represent measured values which simulate the power for the 
respective gradient angles by changing a magnet position to simulate the 
above indicated calculated values. 
Each of the measured values thus represented is a value obtained by 
subtraction of the power in opposition to rolling resistance of the roller 
from the power in opposition to rotating resistance of the roller under 
action of the magnet. 
Accordingly, total power Pa in running on a slope is expressed as follows: 
Pa=(Rr+Ra+Rs).times.g.times.v (watt) 
In order to accurately simulate the total riding resistance in real riding 
as described above, the cycle trainer according to the present invention 
is constructed in the following manner. Rolling resistance is given by a 
rotating roller in contact with a rear wheel. Air resistance is given by a 
first load applying device, that is, a fan attached to one end of the 
shaft of the rotating roller and climbing resistance is given by a second 
load applying device provided on the other end of the roller shaft, that 
is, a disc-shaped conductor as an eddy current load applying device and a 
magnet located to face opposite surfaces of the conductor. The fan has a 
shape which makes it possible for power based on a torque value 
transmitted from the rear wheel to a crank shaft by rotation of the rear 
wheel in contact with the roller to attain the measured value shown in 
FIG. 13, equal to a calculated value. In addition, control of a flux 
amount caused by the magnet and applied to the conductor makes it possible 
for power measured in the same manner to be equal to a calculated value 
simulated as shown in FIG. 14, corresponding to a slope gradient. 
Further, in order to calculate a corresponding speed in real riding of a 
bicycle, it is necessary to take account of slip caused between the rear 
wheel and the roller. 
FIG. 15 is a graph showing a relation between the slip ratio and virtual 
roller shaft torque. 
In this graph, the virtual roller shaft torque (TQ) is calculated by the 
following equation. 
TQ=crank shaft torque x number of revolutions of crank shaft/number of 
revolutions of roller shaft. 
Enforced force N applied to the roller in this case is 24 kgf. 
Since the rolling resistance is given by the rotating roller in contact 
with the rear wheel as described above, it is important to determine the 
enforced force applied to the roller, namely, pressing force applied to 
the tire for accurate simulation of the resistance as well as other 
resistance. 
FIG. 16 is a graph showing the pressing force applied to the tire and power 
in opposition to roller resistance between the roller and the tire, in 
which air pressure of the tire is 6 atm. 
In this graph, the abscissa represents pressing force applied to the tire 
and the ordinate represents power, whereby correlation for each specified 
speed of the bicycle is shown. The pressing force applied to the tire in 
this trainer is set to 24 kgf. so that power against the rolling 
resistance in real riding shown in FIG. 13 is given by the rotating 
roller. Accordingly, although the rolling resistance is expected to differ 
dependent on the condition of the ground surface, it is always possible to 
simulate power with an equal value by setting the pressing force of the 
roller to the tire constantly to a predetermined value, assuming the power 
to be based on a predetermined rolling resistance in real riding. 
Now, the structure of an embodiment of the present invention will be 
specifically described. 
FIG. 1 is a perspective appearance view of a main body of a cycle trainer 
according to the embodiment and FIG. 2 is a schematic side view in which a 
bicycle is mounted on the cycle trainer. 
Referring to those figures, a front frame 20 and a rear frame 22 are 
connected through a wheel base adjusting pipe 5 for adjustment according 
to the length of a wheel base of a bicycle by means of adjusting screws 
18. A front stand 6 for stably setting the cycle trainer is attached to 
the front frame 20 and this stand 6 is placed on a floor 11. Further, a 
front fork fixing holder 7 for fixing a front fork 16 of the bicycle and a 
display support 8 for fixing a display 9 are attached to the front frame 
20. On the other hand, a rear stand 4 having at its top end a rear wheel 
hub axle fixing holder 3 for fixing a hub axle of the rear wheel 10 is 
attached to the rear frame 22. A load applying device 1 on which the rear 
wheel 10 is placed is connected to an end portion of the rear frame 22 
through a load applying device stand 2. By using the cycle trainer thus 
structured, the user can practice training indoors, simulating real 
riding, by rotating the rear wheel 10 through a crank arm 12 using pedals 
14. 
FIGS. 3A and 3B are sectional views taken along the line III--III in FIG. 
1, in which a bicycle is mounted. FIG. 3A shows a state before the roller 
presses the tire of the rear wheel, and FIG. 3B shows a state after the 
roller presses the tire. 
The structure shown in those figures will be described in the following. 
The load applying device stand 2 has a shape freely inserted in the rear 
frame 22 and an adjusting bolt boss 46 for fixing the load applying device 
stand 2 at an arbitrary inserted position is attached to the rear frame 2. 
Spacers 42a and 42b for stable contact with the floor 11 are inserted in 
the rear frame 22 and the load applying device stand 2, respectively. A 
fixing plate 32 to which a coil spring 34 is attached is provided on the 
load applying device stand 2. A support portion 29 for rotatably 
supporting a fixing shaft 28 is attached to one end of the plate 32 and a 
support portion 41 for rotatably supporting a fixing shaft 40 is attached 
to the other end thereof. A roller shaft 24 integrally formed with the 
roller 26 in contact with a rear wheel tire 44 is supported rotatably on a 
pair of support frames 30 provided on both sides of the rear wheel tire 
44. The pair of support frames 30 are rotatable around the fixing shaft 28 
and the coil spring 34 contacts a lower surface of a transverse plate 31 
which connects the pair of support frames 30. An engaging portion 37 fixed 
to the plate 31 and having an end connected to a pedal 36 engages with a 
pedal clamp 38 rotatable about the fixing shaft 40. 
Referring now to FIGS. 1 to 3A and 3B, mounting operation for a bicycle and 
adjusting operation for the load applying device will be described. 
First, the adjusting screws 18 are loosened according to the length of the 
wheel base of the bicycle so that the length of the wheel base adjusting 
pipe 5 is adjusted. Then the adjusting screws 18 are tightened and the 
front fork 16 and the rear wheel hub of the bicycle are fixed by means of 
the front fork fixing holder 7 and the rear wheel hub shaft fixing holder 
3. After the bicycle has been mounted, the bolt applied to the adjusting 
bolt boss 46 is loosened to enable the load applying device stand 2 to be 
movable with respect to the rear frame 22, in a state in which the coil 
spring 34 is compressed, that is, in a state in which a hook portion of 
the pedal clamp 38 is engaged with the engaging portion 37 as a result of 
depressing the pedal 36. Then, the roller shaft 24 is moved together with 
the load applying device stand 2 toward a direction of contact with the 
rear wheel tire 44 and the roller shaft 24 is set at a position in which 
the roller 26 contacts the rear wheel tire 44. In this position, the 
adjusting screw of the adjusting bolt boss 46 is tightened so that the 
load applying device stand 2 is fixed to the rear frame 22. After that, 
when the pedal clamp 38 is disengaged from the engaging portion 37 by 
using the pedal clamp 38, elastic force of the compressed coil spring 34 
energizes the plate 31, so that the roller 26 presses the rear wheel tire 
44 through the support frames 30 and the roller shaft 24. 
This state is shown in FIG. 3B, in which the elastic force of the coil 
spring is set to cause the depression of the rear wheel tire 44 in the 
pressing portion 48 due to the contact with the roller 26 to be 6mm., that 
is, to cause the pressing force applied to the tire to be 24 kgf. 
FIG. 4 is a side view of the load applying device taken from the side 
IV--IV in FIG. 1, in which a cover is removed form the device. 
In FIG. 4, a fan 50 is provided on an end of the roller shaft 24 and it has 
a shape corresponding to power in opposition to air resistance as 
described previously. 
FIG. 5 is a side view of the load applying device taken from the side V--V 
in FIG. 1, in which the cover is also removed from the device. FIG. 6 is a 
sectional view taken along the line VI--VI in FIG. 5. 
Referring to those figures, a copper disc 52 is provided on an end opposite 
to the end on which the fan 50 of the roller shaft 24 is provided, through 
a copper disc fixing hub 76 where cooling fins 54 are formed. A permanent 
magnet 56 of a depressed form where part of the disc 52 is interposed is 
attached to a fixing plate 62. The plate 62 is rotatable about a shaft 58 
to which a torsion coil spring 64 is attached. On the other hand, a wire 
66 introduced through a wire tube 72 is slidably inserted in a set screw 
70 fixed to a support frame 60 and a top end of the wire 66 is fixed by a 
set screw 68 fixed to the plate 62. The wire tube 72 together with the 
wire 66 extends to a load selector (to be described later) provided near 
the display 9 shown in FIG. 2, where the wire 66 is pulled or pushed back 
so that the movement of the wire 66 is transmitted to the top end of the 
wire 66. The plate 62 is rotated around the shaft 58 through the set screw 
68 so that the permanent magnet 56 moves from the position shown by the 
broken lines to the position shown by the solid lines. Since the permanent 
magnet 56 constantly generates a magnetic field in a direction penetrating 
the copper disc 52, eddy current is generated in the copper disc 52. This 
eddy current acts as a force for blocking rotating movement of the copper 
disc 52 and therefore the blocking force, namely, rotation resistance can 
be changed by change of the position of the permanent magnet 56. The area 
of the magnetic field caused by the permanent magnet, namely, an area of 
overlap with the copper disc is set so that the rotation resistance 
corresponds to the above described climbing resistance. 
Further, a slitted disc 80 is attached to the copper disc fixing hub 76 on 
the side of the roller 26 and a pulse generator 78 is fixed to the support 
frames 30, facing opposite surfaces of the slit disc 80. Since the roller 
26 rotates together with the roller shaft 24 by means of a bolt in a 
roller fixing screw hole 74, the rotation of the roller 26 gives rise to 
simultaneous rotation of the slitted disc 80 through the roller shaft 24 
and the copper disc fixing hub 76. 
FIG. 7 is a schematic sectional view specifically showing the above 
mentioned pulse generator and slit disc, and FIG. 8 is a sectional view 
taken along the line VIII--VIII in FIG. 7. 
Referring to these figures, the slit disc 80 is a disc having two different 
radii R1 and R2, and the pulse generator comprises a light emitting diode 
86 and a phototransistor 84 which are located to face only an external 
peripheral portion of the larger radius R1 and contained in a sensor case 
82. Accordingly, each time the slit disc 80 makes a revolution, reception 
and interception of light in the phototransistor 84 with respect to light 
emitted from the light emitting diode 86 are effected alternately once. 
Consequently, the revolution of the slit disc 80, namely, the revolution 
of the roller 26 can be detected based on a light reception signal of the 
phototransistor 84. 
FIG. 9 is a side view of a display and a load selector, and FIG. 10 is a 
sectional view taken along the line X--X in FIG. 9, particularly showing a 
section of the load selector. 
Referring to those figures, a change lever 90 projecting outward is fixedly 
connected to a slit plate 92, which is rotatable about a fixing shaft 98. 
The slit plate 92 has three slits 94 having different distances from the 
fixing shaft 98 or different opening positions. A sensor portion 96 
including three pairs of light emitting diodes 100 and phototransistors 98 
corresponding to the respective portions of the three slits 94 is 
contained in the load selector 88. The change lever 90 can be set to eight 
positions around the fixing shaft 97 and the wire (not shown) is connected 
to the slit plate 92 so that the wire 66 shown in FIG. 5 can be moved 
according to the set position of the change lever 90. A light receiving 
pattern of the three phototransistors 98 for the light emitted from the 
three light emitting diodes 100 changes through the three different slits 
94 dependent on the set position of the change lever 90. Accordingly, 
detection of the light receiving pattern of the phototransistors 98 makes 
it possible to determine the set position of the change lever 90, that is, 
to determine how a slope gradient is set by simulation of climbing 
resistance. 
FIG. 11 is a schematic block diagram showing an electric construction. 
Referring to FIG. 11, a buzzer 110 is connected between a power supply 102 
and a ground power supply through a transistor 108 and the transistor 108 
has its base connected to a CPU 104 through a resistor. Various set data, 
operation programs and the like are stored in the CPU 104 so that various 
arithmetic operations can be performed or various outputs can be provided 
according to the loading conditions of the load applying device. The 
buzzer 110 emits sound by conducting the transistor 108 in response to an 
output signal provided from the CPU 104 during various operations or at 
the end of a set period so that attention is given to the user. The light 
emitting diode 86 is connected to a node N1 and the CPU 104 through 
resistors, and the phototransistor 84 opposed to the light emitting diode 
86 with the slit disc 80 being placed therebetween is connected between 
the CPU 104 and the ground power supply. Light emitting diodes 100a to 
100c are connected between nodes N2 to N4 and the CPU 104, respectively, 
through resistors, and phototransistors 98a to 98c opposed to the light 
emitting diodes 100to 100c with the slit plated 92 having the slits 94 
being placed therebetween are connected between the CPU 104 and the ground 
power supply. The CPU 104 is connected with an LCD panel 106 for 
displaying training setting conditions, elapsed time or the like, and a 
button switch group 112 for entering various set data referring to the 
display on the LCD panel 106. 
In the present embodiment, the power supply 102, the buzzer 110, the CPU 
104, the LCD panel 106 and the button switch group 112 as described above 
are all incorporated in the display device 9. 
FIG. 12 is a schematic flow chart showing various processing operations 
based on the construction of FIG. 11. 
The processing operations will be described with reference to FIG. 12. 
First, when a specified switch of the button switch group 112 is turned on 
at the time of using the trainer, data are initialized and a reference 
time signal is generated (step S1). Then, training is started. The 
rotation speed N of the roller is evaluated (step S3) based on a pulse 
signal generated by the pulse generator 78 (step S2) and power Wf in 
opposition to load under pressure of the roller and load applied by the 
fan 50 is evaluated based on the rotation speed N (step S4). On the other 
hand, a signal based on the light receiving pattern of the three 
phototransistors 98 is generated in the load selector 88 (step S5) and an 
eddy current load level L is determined (step S6). Power Wc in opposition 
to an eddy current load is evaluated based on the rotation speed N of the 
roller and the eddy current load level L (step S7) and power W in 
opposition to total load is evaluated based on the power Wc and the 
previously evaluated power Wf (step S8). This power W is displayed as watt 
data on the LCD panel 106 of the display device 9 (step S9). Further, 
torque TQ of the roller is evaluated based on the roller rotation speed N 
and the total power W (step S10) and a slip radio S caused between the 
roller and the rear wheel tire is evaluated based on the torque TQ (step 
S11). On the other hand, a circumferential speed V of the roller is 
evaluated based on the roller rotation speed N (step S12) and a virtual 
riding speed Va taking account of slip is evaluated by correction of the 
slip radio S (step S13), whereby the virtual riding speed Va is displayed 
on the LCD panel 106 (step S14). 
Consequently, the user can practice cycle training indoors, accurately 
simulating real riding, by referring to the watt data and the virtual 
riding speed displayed on the LCD panel. 
Although the energizing force of the roller pressed by the tire is 
generated by the coil spring in the above described embodiment, it goes 
without saying that other means may be used to generate the energizing 
force insofar as it satisfies a given value. 
In addition, although wind generated by the fan is not specifically 
utilized in the above described embodiment, it may be useful to direct the 
wind to the user as in the prior art in simulating real riding. 
Further, although the clamp is disengaged at a position of contact between 
the roller and the tire as the position for energizing the roller to the 
rear wheel tire, it goes without saying that the clamp may be disengaged 
at other position insofar as the roller and the tire are in a fixed 
positional relation and the elastic force of the coil spring can be made 
to correspond to it. 
As described in the foregoing, according to the present invention, a 
constantly accurate contact force between the drive wheel and the roller 
can be ensured and accordingly it is easy to apply an accurate load for 
simulating real riding. Thus, a cycle trainer with a high precision of 
simulation can be provided. 
Although the present invention has been described and illustrated in 
detail, it is clearly understood that the same is by way of illustration 
and example only and is not to be taken by way of limitation, the spirit 
and scope of the present invention being limited only by the terms of the 
appended claims.