icyclist 

Dave Mayer

Yes, as long as the cog spacing is reduced to 3.94 mm. You would have to fiddle with spacers, and likely having to grind some metal off the back of the #1 cog.

It may be possible to run Shimano 11-speed shifters with a 10-speed era rear derailleur to produce the correct amount of derailleur travel. You'd have to run the math. In my experience in operating all kinds of franken-drivetrains, if the numbers work, then it works perfectly in the real world.

What are you trying to achieve here? You know that since Shimano put their shift cables under the bar wrap, introducing tight friction-causing bends, that their shifting is not as crisp as it was in the older shifters with the exposed housing? My 8-speed Shimano 600, and my 9-speed Tiagra shifters produce clearer, faster and less fussy shifting than my two new 11-speed setups.

If you have problems with your current 9-speed shifters, then get them lubed/serviced. And replace the housings and cables yearly - of course.

fietsbob

OR, Just buy a new 9 speed brifter , Bike Shops still can get them for repairs , from their suppliers ..

dedhed

You may try, but 11 speed Shimano uses a different cable pull from 9 speed.

Bike Gremlin

No - indexing will be off.

"11 speed ROAD shifters
They work with Shimano 11 speed road RDs and with Shimano Tiagra 4700 10 speed road RDs.

By data, they should also work with old Campagnolo RDs, but I haven’t tested this. Old Campagnolo RDs come in 8, 9 and 10 speed variants. They should work with 8 and 9 speed old Campagnolo RDs, as long as the cassette used is Shimano 11 speed road one."

https://bike.bikegremlin.com/1339/bi...compatibility/

CliffordK

Here is a table with cable pulls & etc.
https://en.wikibooks.org/wiki/Bicycl...ive_Components

Unfortunately They seem to have left off a few shifter/cable combinations, including the Shimano 11 shifter.

Ok, so I've uploaded the data from that page into OpenCalc.

My numbers seem to be off slightly. Perhaps due to some of the reported values being calculated, then rounded.

The Shimano 9 cassette has a pitch of about 4.35mm.
The Campagnolo 9 speed cassette has a pitch of about 4.55mm.

Looking at the Shimano 11 speed shifters,

The closest pitch I can get to calculated is using older Shimano 9/10 derailleurs with a 1.7 pull ratio.

This gives one a pitch of about 4.59, or about 0.2mm greater than stock (4.35).

If one uses "Hubbub" cable routing outside of the clamp, I think, then one gets closer with about 4.32 pitch, in theory.

The Campagnolo 9-speed cassette has a pull ratio of about 4.55mm, and would be quite close, especially if one begins in the middle.

CliffordK

My question is why you wish to use 11s shifters with a 9s cassette.

If wheels are the issue, a few solutions are possible.

1) You may be able to do a cut-down cassette, so using 10 speeds on a 11 speed cassette (plus spacers as needed).

2) Some people have successfully machined the inner sprocket group to overhang to the inside, and fit the 11s cassette on an 8/9/10 freeehub. This is especially relevant with the larger rear sprocket sizes. This maybe especially easy to do for flat rear discs (zipp).

Retro Grouch 

What are you ultimately trying to accomplish?

If you are trying to fix the shifting on a bike with a 9-speed cassette, it will always be easier and more reliable using matching parts.
If you are planning to update a 9-speed bike to 11-speed, that too will always be easier and more reliable using all matching parts.