Road Cycling - 2004 Dura Ace

Has anyone yet used a new 10 speed rear derailer on a 9 speed bike, Shimano.com says it will work fine. I am i nthe process of upgrading components and dont know if should just buy the best for now or go for the ultegra rear. Where does the difference in shifting come from 9 to 10 speed, is the diffrence in the shifter or the adjusting screws?

The clicks are in the shifter, so theoretically your old ones should work. The difference between 9 and 10 speed setups is in the width and spacing of the cogs and the width of the chain. There is probably enough play built into the chainrings and the jockey wheels of the derailleur to accomodate either chain.

DEMON

I was under the impression that the Shimano 9 speed chain was going to be used in the new 10 speed.

The derailleur will work fine-I'm using an 8 speed derailleur on my 9 speed road setup (Dura Ace shifters/XTR derailleur). The chain is entirely new. 280 grams now, allegedly just as strong.
www.duraace.com has some good info. Expect substantial price increases, along the lines of what happened with new XTR.

The 10speed chan is the smae as the 9speed.
The 10s derailleur will work just fine with the 9 speed set up

Though the rollers are the same size, the profile is narrower. As far as whether the two chains are incompatible, I haven't gotten to play with that yet. From Shimano's site: The new 10-speed Dura-Ace chain is lighter by an astonishing 24g, yet maintains the same durability as the 9-speed predecessor. The chain also adds a new fluid-smooth feel to the performance of the overall system. The rollers are the same width as 9-speed, insuring the important strength and durability. Weight reduction and the narrower 10-speed profile were achieved by minimizing the contour of the side plates. The super-flush surface of the new plates glides more smoothly across the entire cog set, netting a lighter, smoother, and yet remarkably more durable drive train.