Originally Posted by
Chris_W
Chainring thickness is not a problem at all. On dedicated 10-speed cranks, the rings are placed slightly closer together (put each ring is the same thickness as 9-speed
AFAIK), but the difference in spacing is marginal and normally insignificant. I'd say stick with the 6500 crank and chainrings.
I would first see if you can find a right-hand shifter that will work with the 9-speed stuff. Tiagra would be the best new stuff, or you might get lucky and find a 6500 or 5500 on ebay. Then use whichever of the 2 left-hand levers you have matches the ergonomics/feel of the mis-matched RH lever the best.
OK, so it sounds like 10 speed chainrings alone will not alter the shifting characteristics because the spacing is established by the cranks. I hear people talking about the chain "floating" over the small ring when downshifting the FD. Having to get a 10 speed crank to complete the 10s drivetrain is too much.