Originally Posted by
dddd
For the skipping freewheel sprockets, this picture shows one tooth having been given "the treatment", a very small bevel that is preferably at about 30 degrees to the driven side or "edge" of the tooth rather than at purely a 45 degree angle. The angle is not really that critical, only that the bevel can be very small and yet still effective at preventing the chain's rollers from hitting the sharp corner and "failing to engage" between the teeth (what actually causes the skipping under load).
A thousand thank yous, dddd! I took apart the freewheel to clean and lubricate it, and I used my bench grinder to bevel the 14t/15t sprockets (perhaps a bit too aggressively). The 14t now engages under the greatest torque I can produce, and the 15t is almost as good but one to two teeth still skip when I hammer on it. It may be too far gone but I could try again or leave well enough alone as it works under normal load. Interestingly, I tried using a newer 9 speed chain but the skipping was much worse. Not sure why? Anyway, I'm now extremely happy with the drivetrain, so thanks all for the advice, especially dddd!
