I have a 9 speed shimano set up and want to upgrade my shifters to Ultegra level. Will the Ultegra 6600 10 speed shifters work or should I search out the non-series 6500s? On the left side, it is often claimed that the shifter is compatable for both triple and double set ups. Does the same logic apply to the rear i.e. that a 10 speed shifter will work with a 9 speed cassette?

No, a 10sp shifter and 9sp cassette won't work. You can still use the 9sp rear derailleur, though. Just add a 10sp cassette to complete the conversion.

I use a wheel with a 9-speed cassette on my trainer. It works fine with my Ultegra 6600 shifters.

Good advice above.

You do realise that the "Ultegra" name was around way before 6600 came out. i.e. 6500 is also called Ultegra. It even had Ultegra SL-style "Ultegra" on the actual silver lever bit of the STI.

Actually, yes.

The 10 speed shifters will work on an otherwise 9 speed setup. There is a certain way you are supposed to anchor the cable to the rear der. to make this work. You'll have an extra click but the indexing will work properly if the cable is routed properly.

This is what you need to know:
https://sheldonbrown.com/dura-ace.html

I couldn't resist the deal Nashbar had on 10 speed Ultegra brifters this weekend, but I also have a 9 speed setup.

it'll work fine. just a little tinkering needed. usually a double-shift is needed to shift gears. just do not expect perfect shifts.

https://jtekengineering.com/shiftmate.htm

Shiftmate Model #2

I looked at the link. How does it work? Is the pulley not round?

If you look on ebay you can get a good deal on 10 spd brifters and derailleurs

I got Ultegra shifters, Dura-Ace rear derailleur, 105 cassette, and a Dura-Ace chain for just over 300 shipped, seems like a pretty good deal to me... Though I'm coming from Sora 8 spd, so anything is better.

I've wondered that myself.

Oh good, I thought I must be nuts. If the pulley is round I don't see how it could do anything, but it must, right?

I've never seen one in person, but my understanding is that there are two pulleys of slightly different sizes. The cable wraps around one pulley, through a groove, and then around the other pulley.

See https://jtekengineering.com/Images/Sh...structions.pdf

I have set one of these up and that is the correct explanation.

Thanks for the input everyone. What I am hearing is that it can be done, but with some modification and that smoothness may be sacraficed. I have decided to go with the ST 6510 for the 9 speed set up.

If you're going to spend the coin on Ultegra brifters, why not go 10speed? To get it to work well, you'd want a 10 speed cassette and chain.

However, you can get a new 105 cassette, and chain for a fraction of what you'll spend on the brifters. And those things have to be replaced on a regular basis anyway.

That would probably make sense but all my current stuff is 9 speed, including a brand new cassette and chain plus the cassette on my spare wheel set.