gone
03-04-2006, 12:28 PM
OK, I know this topic has been done to death but here's a wrinkle that I've not seen discussed anywhere. Here's the setup:
Two bikes, both with 10 speed rear derailleurs and cassettes and D/A ten speed chains.
Bike 1 has indexed 10 speed D/A downtube shifters and D/A 53/39 9 speed chainrings and a D/A 10 speed front derailleur.
Bike 2 has D/A brifters and an FSA compact crank and an FSA compact front derailleur, 50/36 chainrings.
Problem: when on any cog to the right (smaller) of the center of the cassette, shifting down from the big ring to the small results in the chain landing "between" the chainrings, against the big ring and not engaging the teeth on the small ring resulting in the cranks (me) spinning frantically. It will stay this way i.e., it will not just do it for a few turns of the crank and then engage, and the only "on the road" fix is to shift the rear cassette to a larger cog.
All components basically new, chainlength on both bikes is correct, chainline on both bikes is good. I've tried adjusting the limit screw on the FD to the point where it nearly throws off the chain to the inside to make the derailleur come over farther with no change in behavior.
It appears that the spacing between the chainrings is slightly too large for the 10 speed chain. It's narrow enough that the chain doesn't get wedged between them but too wide so the chain doesn't naturally fall onto the small ring. Is there a difference between 9 & 10 speed chainrings (spacing, pins or ramps) and is the only solution to buy new chainrings?
Anybody else seen or experienced this? Thanks in advance for any thoughts and suggestions.
Two bikes, both with 10 speed rear derailleurs and cassettes and D/A ten speed chains.
Bike 1 has indexed 10 speed D/A downtube shifters and D/A 53/39 9 speed chainrings and a D/A 10 speed front derailleur.
Bike 2 has D/A brifters and an FSA compact crank and an FSA compact front derailleur, 50/36 chainrings.
Problem: when on any cog to the right (smaller) of the center of the cassette, shifting down from the big ring to the small results in the chain landing "between" the chainrings, against the big ring and not engaging the teeth on the small ring resulting in the cranks (me) spinning frantically. It will stay this way i.e., it will not just do it for a few turns of the crank and then engage, and the only "on the road" fix is to shift the rear cassette to a larger cog.
All components basically new, chainlength on both bikes is correct, chainline on both bikes is good. I've tried adjusting the limit screw on the FD to the point where it nearly throws off the chain to the inside to make the derailleur come over farther with no change in behavior.
It appears that the spacing between the chainrings is slightly too large for the 10 speed chain. It's narrow enough that the chain doesn't get wedged between them but too wide so the chain doesn't naturally fall onto the small ring. Is there a difference between 9 & 10 speed chainrings (spacing, pins or ramps) and is the only solution to buy new chainrings?
Anybody else seen or experienced this? Thanks in advance for any thoughts and suggestions.