Bent Big Ring

[Jezston]

Took my bike into the LBS over the weekend as I was hearing some weird scrapey noises in high gears. Turns out the large ring on my crankset is bent, and is scraping slightly against the chain which usually sits on the middle ring, when in higher gears.

I have absolutely no idea how it got bent, I've not had a single off on this bike nor ever dropped it so have no idea why it's bent. Took it in to Evans where I bought it and had it looked at and they say it's definitely been involved in an impact and they don't think it'll be covered by warranty, which sucks.

So I have two questions:

1. Any way I could hassle them into offering a warrantly replacement on this? Can I claim it must be defective, and even if they insist I've hit it do I have any recourse to say no I didn't and is the onus of proof on me or them to prove I haven't?

2. I never use the outer ring anyway, if I can't get it replaced for free, any harm in bashing it back into shape so it at least isn't scraping the chain when it's in its usual home of the middle ring?

 

[actonblue]

What sort of groupset is it? But you can bend the offending teeth back into place with a big adjustable spanner.
You could have bent it with a bad gear change or someone could have bashed your bike if you had locked up somewhere.
It is not difficult to resolve.

Cheers.

Colin.

 

[HJ]

When mine got bent, the LBS just hit it with a hammer, NB they didn't charge me for this service

 

[actonblue]

Molegrips not such a desperate solution.

 

[MartinC]

If you want to be really posh use one of these - http://www.parktool.com/products/detail.asp?cat=14&item=DT-2

Otherwise stilsons or a mole grip may do. Or take it off and hammer it on a flat surface. Try to bend it as little as possible (but if it's steel do what you like) i.e. try not to bend it to far so that you have to bend it back again. Hardened aluminium doesn't like being bent to often and will fatigue much sooner than steel.

 

[Jezston]

Cheers gents, hammering it on a flat surface, with a rubber ended hammer, sounds like a plan!

 

[HJ]

If you want to be really posh use one of these - http://www.parktool.com/products/detail.asp?cat=14&item=DT-2

Otherwise stilsons or a mole grip may do. Or take it off and hammer it on a flat surface. Try to bend it as little as possible (but if it's steel do what you like) i.e. try not to bend it to far so that you have to bend it back again. Hardened aluminium doesn't like being bent to often and will fatigue much sooner than steel.

The problem with aluminium is not only does it bend but stretches as well, you can't just bend it back into shape....

 

[HLaB]

I think I saw on one website once (it might of been bike tutor) where they used (tightened) an adjustable spanner to sort out the teeth of a chainring.

 

[Flying Dodo]

Many years ago, I've used a pair of mole grips to straighten a steel chain ring. As mentioned above, there could be a problem with aluminium, but provided you do it slowly, you've got nothing to lose. After all, it doesn't work now, so if you break off a tooth, it's no worse!

 

[Ticktockmy]

Give it a good bashing, show it who is boss..LOL you cannot beat a hammer to solve all our problems.seriously just use a pice of wood to protect the teeth and bash it backing shape

 

[Jezston]

I shall be seeking out a rubber hammer today.

I've realised this issue has also killed my chain. Wah.

 

[fossyant]

Adjustable Spanner is all you need......... lock onto bent section and ease straight a little. Check, then redo.

 

[battered]

I just use 2 hammers in opposition, works a treat.

 

[Tynan]

never use the big ring?