Tricross Front Derailleur Issues

Octopus1

I have a 2011 Tricross Sport Triple - Tiagra shifters and triple chainset.

My problem is with the front derailleur, it constantly seems to fall out of alignment and prevent shifting to the 50 ring. It's been back to the shop 4 times over the last two months. Used daily, 3 x a week for 25 mile cycle to work, the problem occurs when too much stress on the FD appears to pull it out of alignment. Bike shop advised that they cannot tighten it too much or will strip the threads. Paint has just fallen off the FD braze on so I don't want to play about with it too much. The current fix is to bend the FD into alignment with the chainset big ring. I have to do this every other day.

Whilst I like the tricross, the unreliability of the FD means I am tempted to get rid of it or swap out the groupset to a compact APEX like my other bikes which don't have these sort of problems.

Anybody got the same sort of problem ? Or a more permant fix ?

thanks

slowbike

I've got the same bike - but not the problem.

What on earth is stressing the FD? other than when shifting it should only be stressed by the springs in the mech and the cable. The stress when shifting should only be minor.

So - what is being adjusted? Is it the cable slipping through the clamp? Perhaps the cable has got greasy and slippery or just flattened too much for the clamp to grip - change the cable is a quick fix.
If the whole mech is slipping on the fixing to the bike then that's really odd - is it up/down or left/right rotation?

Octopus1

The angle of the FD changes, I think its the actually mount itself i.e. the braze on.

With a sharp gear change the angle changes and the FD cage is no longer parallel to the bigh ring. This means that the cage can't act as a guide to move the chain to the correct ring. Effectively it doesn't pick up the gear change. Only way to solve it is to "bend" the cage back to parallel.

I've been using a specialized concept store to try to fix this, its where i bought the bike but no luck in a long term fix.

slowbike

So what's going out of alignment - the cage or the whole derallieur ...

if the former then get a replacement derallieur, if the later then the mount to the braze on needs investigating - I think you said that the paint is coming off the braze mount - so is the braze mount bending out of shape?
Metal will fatigue and if you're constantly having to straighten it then it will weaken and eventually snap - possibly change to a band-on mount.

I'm not sure which Specialized Concept store you're using, but it sounds like they don't really know what they're doing - or are stalling you ... it's simple mechanics ...

Out of interest - how old is the bike and how many miles have you covered? Mine is 2011 but bought beginning of 2013 (new) and it's done >1000 miles so far. The only issue I had was with the front wheel having dry bearings which Specialized sorted with a replacement wheel.

onbike 1939

The problem as I read it is that the FD is twisting around on the curved surface of the braze-on mounting. I've had a similar issue. I'd try some Loctite (blue) on the clamping bolt and on the inner curved surface of the FD.

friedpizzainbatter

I had a similar problem with a Tricross, not sure if it's the same but here goes.

The front derailleur could not get the chain onto the big ring without a struggle, if I put it on a stand it seemed to shift fine, it was only when I was riding it.

I'd had the crankset replaced by my LBS a year before this and it turned out the BB was the incorrect width for the new crankset, I'd had it into three different bike shops before someone worked out what the problem was. I got it replaced and the problem went away.

desweller

Braze-one derailleurs use a bolt that passes through the mounting plate, right?

If the plate is not splitting away from the frame it sounds like your friendly bicycle mechanic is just a bit scared of tightening that screw up. I'd give it a bit of stick; they're pretty strong.