[TheDon]

I'm looking to replace my 9 speed tiagra sti levers with ultegra 10 speed levers. Do I need to upgrade my whole drive train or can I just add a 10 speed cassette and chain?

 

[TurboTurtle]

I'm looking to replace my 9 speed tiagra sti levers with ultegra 10 speed levers. Do I need to upgrade my whole drive train or can I just add a 10 speed cassette and chain?

Correct - shifters, cassette and chain. Be aware that Ultegra-10 levers are double or triple specific, so get the right ones. Also there will be a spacer that comes with the cassette that should be used. - TF

 

[vitin]

Correct - shifters, cassette and chain. Be aware that Ultegra-10 levers are double or triple specific, so get the right ones. Also there will be a spacer that comes with the cassette that should be used. - TF

running this setup more 8 mos no issues in shifting and works good with 9 speed drivetrain and completed 1 century aprox 95 miles 152 km in this setup fajardo to ponce in puerto rico in 6'02 hours avg mph 15.5 25.2 km in variouios terrain includes hilly passes and flat lands

 

[grayfox2014]

hey, I just finished changing all of my tiagra drivetrain over to ultegra 10 speed. I'm Sorry to say it but you have to switch it all over.

If you go to this link then you can find some compatibilty charts

http://bike.shimano.com/publish/con.../compatibility_charts/road_compatibility.html