MTB Bent Cog...

[akb]

So.. 1030pm, having a leisurely ride on the MTB on the road enjoying the use of the Hope 1 in the dark, changed down a gear to start the gradual uphill climb when the chain came off. Not a prob, put it back on and then tried to continue. But I couldnt. Somehow, the chaing coming off has caused one of the front cogs to bend....thus limiting the rotation of said cog, causing it to stop spinning against the frame. Phone the missus (who is 8 months pregnant!) get a mouthful and she comes and picks me up. Not a problem.
The cogs should be able to withstand the occasional chain slip shouldnt it? I brought the bike last April )2012). Suntour cogs. Is this a user error or product failure? I.e, could I take it back to the shop and ask them to fix it without charge!

Obsolutely gutted to not have the MTB; recently changed jobs which is too far to commute so have been going out twice a week on the MTB for fitness. No I cant and I miss my rides.

Will post a photo this evening to show the damage. Actually...it looks like the whole cassette (i assume this is what it is called) has deformed.

Thanks in advance.

 

[Cubist]

It sounds like you have bent one of your chainrings. It should be able to withstand quite an amount of force before it deforms like you describe.

What sort of bike? How long have you had it? Did you buy it new?

 

[akb]

Thanks for the response cubist. It's a 2012 Spesh Rockhopper, brought new April 2012. Ridden less times than my cheap commuter which has never had problems so truly peeved. I know not the top end bike, but for 600 quid I thought it should last a bit longer.

 

[Cubist]

Give it a go back at the shop. If they won't entertain it there are some Shimano chainsets out there in internetworld for £25 or so,probably cheaper than replacing the Suntour (which is probably going to bend again...)

 

[actonblue]

If it is just a single tooth try bending it back into position using an adjustable spanner.
Not a disaster, I think there is a howto on the Park Tools website.

 

[akb]

More than a single tooth, at least 3. Have tried allsorts of ways to bend it back into place using various tool but no luck.

 

[fossyant]

Just get another chain ring/chain set

 

[akb]

Not a problem getting one, but should I really need to on a 16month old bike?

 

[fossyant]

It's a MTB. Who knows how its used.

Way out of warranty. I don't know how you service your bikes, but any off road stuff, mine get a good service, ride it hard, then go about cleaning the crap out. It doesn't take much to smash some bits off. We don't know what is your experience of bikes is.

Some information might help you.

 

[akb]

Bike is well looked after, always lubed before and after a ride. The riding itself is no more than 10 miles a couple of times a week on the local bridal ways. Bike always cleaned if extra dirty.

 

[fossyant]

To be frank, a chain coming off can cause damage if you continue to pedal. It's one of those things, and cheap chain rings won't be as durable. Any photos

 

[akb]

To be frank, a chain coming off can cause damage if you continue to pedal. It's one of those things, and cheap chain rings won't be as durable. Any photos

Finally got round to taking some photos!

Do I have a case for Not Fit For Purpose or should I accept as wear and tear?

 

[akb]

Looking at the photos I have just taken, would I be better of replacing the cassette as it looks worn to my untrained eye.

 

[RecordAceFromNew]

I must say I can't think of any reason why the teeth of the innermost ring could be bent inwards by the chain coming off...

 

[RecordAceFromNew]

Looking at the photos I have just taken, would I be better of replacing the cassette as it looks worn to my untrained eye.

If you mean the chainrings, the teeth are not meant to be uniform, so the fact they look irregular doesn't mean they are worn out.