's Forum Archives - Cyclo-Cross

Archive Home >> Cyclo-Cross(1 2 3 )

Are STI and XTR front deralier compatible?(5 posts)

Are STI and XTR front deralier compatible?Polar
Oct 27, 2002 7:36 AM
I have 8 speed 105 STI and FD-952 XTR FD, are they shifing at same ratio?
re: Are STI and XTR front deralier compatible?Max11
Oct 27, 2002 8:31 PM
I have a 9 spd ultegra sti with xtr front and it works fine for me.
re: Are STI and XTR front deralier compatible?OffRoadTourer
Oct 28, 2002 6:08 AM
I have 8 speed Sora STI and FD-M901 XTR front mech (earlier non-compact drive type). I have managed to get it working reliably after a lot of trouble. Because, to answer your question, no they do not shift at the same ratio, but it is damn close.

If you want proof, because some people argue this, go and look at the Shimano website. In among all the road groups is a mysterious set of MTB-like rapidfire shifters for people setting up sport bikes with flat bars. Lo and behold, they make a specific front derailler to work with these shifters. It would appear MTB Rapidfire and Road STI pull different amounts of cable.

My solution? Well the problem seemed to be getting enough cable tension to get the chain to reliably move up to higher chainrings while still allowing the chain to drop to granny (I have a Sora triple crankset). So (after many other failed attempts) I disconnected the cable, screwed the lower limit screw in about half a turn, pulled the cable as tight as I could and reconnected it, then let the limit screw out half a turn again which effectively leaves the cable tighter than you could ever pull it. I can't see why this worked when my barrel adjuster didn't help but it was the only thing that made all the difference. It still rubs ever-so-slightly in absolute top gear only, not enough to matter. (People get paranoid about chain rub, ever listen to a chain going through a downhill MTB chain guide? When gravity is your co-pilot you can afford to lose 0.0001% of your drivetrain efficiency).

Best of luck, hope you have less headaches than I did. Just keep telling yourself "It CAN be done!", that or go out and buy an eight speed road derailler, the Sora one looks like an old school XT.
re: Are STI and XTR front deralier compatible?atpjunkie
Oct 28, 2002 3:24 PM
ran Ultegra STI's with XTR top pull w/ no trouble. In fact it was stock spec on 2000 Specialized S-Works cx bikes. I don't think a company would spec if it didn't work. Run barends now.
Pretty sure your proof is relabelled Deore parts (nm)TFerguson
Oct 28, 2002 4:10 PM