FD Change on Modern Tourer

[RobMac]

Heres the set-up, FD4503 (Tiagra Triple), RD771 (XT), chain set 48,38,28, (3x9).
Can I fit a FD771 XT to replace the Tiagra?
Will it cope?
:?

 

[cce]

Why would you want to?

and for what it's worth, road front derailleurs have a different curvature to suit the larger chainrings. I've got a sneaking suspicion they have slightly different cable pull too.

 

[hamster]

I depends on the front shifters, as CCE says the cable pull is different for the front mech between road and MTB. If you are using bar-ends, swap away and good luck.
The CTC shimergo pages also show a mod to an MTB front where you clamp the cable on the wrong side of the bolt to correct the pull ratio. As modern MTB stuff is designed for a bigger front chainset again, it would say give it a try.

 

[RobMac]

To answer CCE's question, "Why would you want to?"
OCD .................. the FD has been bugging me since I got the bike in '09'


And Hamster the bike has STI levers (brake/shifter combined) I don't particularly like droop bars either.

 

[hamster]

IIRC all the later MTB FDs are designed for 44T outers. The inner will work fine as it's a larger ring. I know that they say the curvature has to be matched, but normally it doesn't seem to matter. I think Shimano play cautious as it also depends on the seat tube angle. I wouldn't try it with a 52, but with 48 I reckon you will get away with it.

 

[stewlewis]

The problems are with the 48/38/28, the best Shimano FD within spec. to work with those is the Nexave FD-T401, it what I use on my hybrid.

http://techdocs.shimano.com/media/techd ... 605628.pdf

I found modern MTB mechs don't like to play with a 48t ring. They work as has been said but the setting up tolerance is fine to get right and stay right.

Whereas road mechs don't like only a 10 tooth difference from the top ring to the middle but the cage does have a larger curve to clear the 48t.

 

[RobMac]

OK you've convinced me I'll stick with the Tiagra :?
Anybody got a XT sticker?


Thanks for taking the times guys.

 

[stewlewis]

Yeah I was like that when experimenting; Nexave! with XT at the back good god!!
I tried a lot of MTB and Road FDs and went back to the Nexave. But then I rode the bike, and it shifted and it didn't make noise and didn't need constant trimming, and I kinda forgot it was Nexave and then you know it didn't matter at all.