Bicycle chain rings with ramps
Embodiments of the present invention include bicycle chain rings for bicycles having specially shaped ramps, tapers and profiled teeth for improved shifting performance. Additional embodiments of the bicycle chain rings of the present invention may be configured with one or more additional features formed within the chain rings including a transition slide, a tapered ramp face, a ramp bridge, a ramp lead, a trailing transition slide and a wear pin.
1. A bicycle chain ring, comprising:
ramps disposed about an inner surface of the bicycle chain ring for engaging one or more outer chain links of a bicycle chain during an up-shift, each ramp configured with a lifting surface and a ramp face; and
at least one of the ramps further comprising a transition slide disposed along a leading edge of each ramp, the transition slide forming a bevel tapering the lifting surface back to the ramp face at an inner periphery of an inner opening of the chain ring.
2. The bicycle chain ring according to claim 1 , further comprising a ramp bridge between two adjacent ramps, the bridge configured to prevent chain snags between ramps.
3. The bicycle chain ring according to claim 2 , wherein the ramp bridge is located adjacent to the inner periphery.
4. The bicycle chain ring according to claim 1 , wherein each of the ramps further comprises a ramp lead disposed between adjacent ramps, the ramp lead comprising an angled transition from a flat plane region to the ramp face.
5. The bicycle chain ring according to claim 4 , wherein the angled transition tapers in thickness from nearest the inner periphery to an outer periphery adjacent a tooth of the chain ring.
6. The bicycle chain ring according to claim 5 , further comprising a trailing transition slide disposed on a ramp bridge opposite the transition slide, the trailing transition slide tapering down to the ramp face.
7. The bicycle chain ring according to claim 1 , further comprising wear pins embedded in each of the ramps to minimize wearing of the lifting surface.
8. The bicycle chain ring according to claim 1 , wherein the lifting surface is planar.
9. A bicycle chain ring, comprising:
a ramp formed on an inner surface of the bicycle chain ring, the ramp comprising a raised structure with a lifting surface perpendicular to a plane of the inner surface;
a ramp face adjacent to the lifting surface, the ramp face forming a planar surface tapering a thickness of the bicycle chain ring in a radial direction;
the lifting surface and ramp face configured for engaging one or more outer chain links of a bicycle chain during an up-shift; and
a wear pin embedded within the raised structure and adjacent the lifting surface for minimizing wear to the lifting surface.
10. The bicycle chain ring according to claim 9 , further comprising a ramp lead disposed between the ramp and a second ramp face, the ramp lead tapered up from a flat plane region to the radially tapered ramp face.
11. The bicycle chain ring according to claim 10 , further comprising a smoothed ramp bridge extending from a leading edge of the ramp along an inner periphery of an inner opening of the chain ring to the ramp lead.
12. The bicycle chain ring according to claim 11 , further comprising a transition slide disposed along a leading edge of the ramp and the ramp bridge, the transition slide forming a bevel tapering the lifting surface back to the ramp face at the inner periphery of the inner opening of the chain ring.
13. The bicycle chain ring according to claim 11 , further comprising a trailing transition slide disposed along a trailing edge of the ramp bridge, the trailing transition slide forming a bevel tapering the trailing edge of the ramp bridge to a second ramp face at the inner periphery of the inner opening of the chain ring.
14. The bicycle chain ring according to claim 9 , comprising a large mountain bike chain ring further comprising 44 teeth along an outer periphery and four mounting bolt holes.
15. The bicycle chain ring according to claim 9 , comprising a medium mountain bike chain ring further comprising 32 teeth along an outer periphery and four mounting bolt holes.
16. The bicycle chain ring according to claim 9 , comprising a large cyclocross chain ring further comprising 44 teeth along an outer periphery and five mounting bolt holes.
17. The bicycle chain ring according to claim 9 , comprising a large road bike chain ring further comprising 53 teeth along an outer periphery and five mounting bolt holes.
18. The bicycle chain ring according to claim 9 , comprising a medium road bike chain ring further comprising 39 teeth along an outer periphery and five mounting bolt holes.