Shimano 9 and 10 speed compatability

[mercianman]

I have a bike that has been running on a Tiagra 9 speed set up, but I need to replace the front and rear derailleur. Would it be ok to use a new 10 speed version of each of these components, or would I need to look for a used or NOS 9 speed version

[Brucey]

the only 4700 series 10s derailleur that might be backwards compatible to 9s is the front derailleur meant for triple chainsets. Everything else is different.


Which bits do you need to change? Would you want to have different gear ratios? -if so there are plenty of other choices that might allow you to change the gear ratios; for example any MTB 9s rear derailleur will work with your shifters.

cheers

[mercianman]

I take it the MTB is compatible with a road bike set up?

[Polisman]

Most 9 speed parts will run with ten, and vice versa, with a little bit of fettling.

[cycleruk]

This will give you a pointer to what is interchangeable :-
https://en.wikibooks.org/wiki/Bicycles/ ... Dimensions

9 speed RD's from Road and MTB are interchangeable. 10 speed road RD's will also work but not 10 speed MTB mech's.
MTB front mech's are not interchangeable with road versions.. MTB front mech's need a larger cable pull than road front mech's.

The new Tiagra 10 speed looks to be compatible with 11 speed.

[Brucey]

Most 9 speed parts will run with ten, and vice versa, with a little bit of fettling.

10 speed road RD's will also work ...

Just to be clear, Shimano road 10s rear derailleurs will work in a 9s system except for Tiagra 4700

cheers

[Redvee]

This Shimano compatability chart might be of use.

https://productinfo.shimano.com/#/com?a ... &cid=C-453

[mcshroom]

Advice on the rear is explained better than i would above, but I would choose a 9sp front derailleur. I've found with a 9sp front on an 8sp system it is very difficult to avoid chain rub at the cassette extremes.

The current Sora 9sp has the same cable pull as 9sp Tiagra.