Rear mech broken off?

chuckcork

Anyone ever had this happen to them? Taking off at a set of lights, suddenly clunk and all goes stuck, coast to the side of the road and the rear mech had snapped off. It was a Shimano 105 10-speed.

The bike, a Dawes Audax Supreme 2008, was only about 3 weeks or so old, in which time I'd done about 650km on it, and while I hadn't had a first service to take care of cable stretch (the indexing needed some seeing to) the chain was well lubed with Finish Line Pro Road and I had given it a clean in that time as well.

The response to the warranty claim for it came back from the UK distributor thus:

"We regret that we are unable to accept this claim in such a case as where the derailleur has been visibly forced.

We have come to this conclusion as this is not a defect in the manufacture, but has been caused by the derailleur being dragged upward and back until it has hit the dropout. When at the contact point, the derailleur twists the chain causing severe sideways pressure and usually bending (or breaking) of the chain. This happens when the derailleur is caught by debris, or in the wheel itself, and dragged round by the wheel. We can tell this from marks on the derailleur body where it made contact with the frame"

This response seems to say a set of circumstances happened which cause it to break, and throws up a set of spurious things that might have (but didn't) cause it to happen, therefore tough luck.

Only problem is I was I the middle of the gear range, and I don't really know how something woudl have *suddenly* got stuck in the chain or derailleur to cause it to stick that way, unless a chain link went suddenly and seriously stiff. I had already ridden the bike in that day to work and was on my way home again. If it went into the wheel it was when it was failing and after the problem had occured, so they're telling me nothing new there.

Any suggestions other than don't bother with a Shimano 105 groupset in the future?

The shop unfortunately has just said its nothing to do with them or the bike manufacturer (Dawes, I use the term manufacturer advisedly) so I'm out of pocket for a new gear changer and a chain after only a few weeks of having a bike.

bendertherobot

Well, the marks on the derailluer could easily be caused as it becomes damaged so that "proof" as far as they are concerned is a red herring.

The new Sale of Goods Act states that faults occuring within 6 months of sale are taken to be faults exisitng at the point of sale. The onus is on them to disprove this. They've tried to do that, and, IMO, failed.

Write to them and state again clearly that no such collision occurred and that the gear sheared as you pulled off.

Monty Dog

Your claim is with the shop - don't let them fob you off with the manufacturer. There's quite rightly no warranty claim if there's no problem with the frame - but the shop could be liable if the bike wasn't set-up correctly. Difficult to concur with your claim without seeing the parts e.g. was the gear hanger bent or the mech stop screws set incorrectly? Equally, I have seen a jammed chain cause the mech to twist into the wheel wrecking the wheel, frame and drivetrain into the process.