Multi-speed rear drive for a bicycle
A system and method for simple transmission of a multi-speed bicycle is provided. A bicycle can have a transmission that can be toggled by a kickback shifting mechanism. A rear wheel hub can support a freewheel having a high speed gear sprocket and a low speed gear sprocket with dedicated chains to create dedicated gear-shifting. Rotating the pedal shaft in the non-drive direction approximately one-quarter rotation can toggle the transmission between the first gear ratio and the second gear ratio with a shifting surface that alternately allows driving engagement of the high speed gear sprocket with the rear wheel driver.
1. A multi-speed transmission for a bicycle wheel hub, comprising:
a driver to be arranged on a longitudinal axis of the bicycle wheel hub, the driver including a groove and a plurality of drive teeth; and
a multi-speed freewheel arranged on the longitudinal axis of the bicycle wheel hub, the multi-speed freewheel comprising:
a first sprocket to be connected to a first pedal drive sprocket of a bicycle;
a second sprocket to be connected to a second pedal drive sprocket of the bicycle,
a plurality of pawls arranged radially on the second sprocket to engage with the drive teeth when a pedal shaft is rotated in a non-drive direction a non-drive direction for a predetermined rotation,
a plurality of bias elements arranged radially within an interior area of the second sprocket to bias the plurality of pawls toward the drive teeth, and
a shift ring arranged within the interior area of the second sprocket to selectively block engagement of the plurality of pawls with the drive teeth.
2. The multi-speed transmission of claim 1 , wherein the first sprocket has a first gear ratio and the second sprocket has a second gear ratio, and wherein the second gear ratio is different than the first gear ratio.
3. The multi-speed transmission of claim 2 , wherein the multi-speed freewheel is toggled between the first gear ratio and the second gear ratio by rotating the multi-speed freewheel in the non-drive direction.
4. The multi-speed transmission of claim 3 , wherein the multi-speed freewheel is toggled between the second gear ratio and the first gear ratio by rotating the multi-speed freewheel in the non-drive direction.
5. The multi-speed transmission of claim 2 , wherein the multi-speed freewheel is continually toggled between the first gear ratio and the second gear ratio by continually rotating the multi-speed freewheel in the non-drive direction.
6. The multi-speed transmission of claim 2 , wherein the second gear ratio is higher than the first gear ratio.
7. The multi-speed transmission of claim 2 , wherein the second gear ratio is lower than the first gear ratio.
8. The multi-speed transmission of claim 1 , wherein the shift ring further comprises a friction element.
9. The multi-speed transmission of claim 8 , wherein the friction element further has a diameter.
10. The multi-speed transmission of claim 9 , wherein the diameter of the friction element increases when the shift ring is rotated in the non-drive direction.
11. The multi-speed transmission of claim 9 , wherein the diameter of the friction element decreases when the shift ring is rotated in a drive direction.
12. A multi-speed transmission for a bicycle, comprising:
a driver having a groove and a plurality of drive teeth;
a first sprocket pawl arranged in the groove;
a first sprocket engaged with the first sprocket pawl, the first sprocket having a first gear ratio;
a second sprocket having a second gear ratio higher than the first gear ratio;
a second sprocket pawl arranged within the second sprocket to selectively drivingly engage one or more of the plurality of drive teeth; and
a shift ring to rotate with the first sprocket and extend within an interior area of the second sprocket, the shift ring including a notch to selectively engage the second sprocket pawl and prevent the second sprocket pawl from drivingly engaging the one or more of the plurality of drive teeth.
13. A multi-speed transmission for a bicycle, comprising:
a first sprocket pawl arranged in a groove of a driver,
a first sprocket engaged with the first sprocket pawl, the first sprocket having a first gear ratio;
a second sprocket having a second gear ratio higher than the first gear ratio;
a second sprocket pawl arranged within the second sprocket to selectively drivingly engage one or more of a plurality of drive teeth of the driver; and
a shift ring to rotate with the first sprocket and extend within an interior area of the second sprocket, the shift ring including a notch to selectively engage the second sprocket pawl and prevent the second sprocket pawl from drivingly engaging the one or more of the plurality of drive teeth.
14. The multi-speed transmission of claim 13 , wherein the multi-speed transmission is continually toggled between the first gear ratio and the second gear ratio by continually rotating the multi-speed transmission in a non-drive direction.
15. The multi-speed transmission of claim 13 , wherein the multi-speed transmission is toggled between the first gear ratio and the second gear ratio by rotating the multi-speed transmission in a non-drive direction.
16. The multi-speed transmission of claim 13 , wherein the multi-speed transmission is toggled between the second gear ratio and the first gear ratio by rotating the multi-speed transmission in a non-drive direction.
17. The multi-speed transmission of claim 13 , wherein the shift ring further comprises a friction element.
18. The multi-speed transmission of claim 17 , wherein the friction element has a diameter.
19. The multi-speed transmission of claim 18 , wherein the diameter of the friction element changes when the shift ring is rotated in a non-drive direction.