Shimano 9/10 compatability

Dan H said:

Can I use an Utegra RD6500 (9speed)in place of a RD6600(10 speed)?
I installed the 6500 and it seems to work ok except it takes 2 clicks to go from smallest cog to the next and 2 clicks to off the largest cog. All the rest line up great. The controls are 6600.

The 9s RD should work perfectly well with a 10s drivetrain. There should not be any of shifting compromises that you describe. I suspect that your cable tension needs adjustment and possibly the inner and outer limit screws.

Thanks for the tip!
I replaced the dirty housing and that took care of it. The system shifts pretty well now but not perfect. I suspect the top tube routing adds friction to the system so if there is any drag at all, performance is affected. I think a Rollamajig might help.

John M said:

The 9s RD should work perfectly well with a 10s drivetrain. There should not be any of shifting compromises that you describe. I suspect that your cable tension needs adjustment and possibly the inner and outer limit screws.