Pearson Touche: Chain jumping off rear cog

Had this Touche for about four months and love it however this is a problem that may get me killed. Soon after purchase the chain jumped off the rear cog, jammed between it and the wheel causing it to lock.

I thought this was because the chain was too slack so tightened it up. Unfortunately it seems to keep happening no matter how I tension the chain. The last time (last week) it happened at speed and I barely kepy control of the bike and it left two scratches in the chain stays.

Am taking it to the Pearson shop (who seem puzzled) on Saturday to see what they make of it). Also met a guy outside Condor after the Rapha sample sale who said he had the same problem and took it back to Pearsons who changed the rear cog and that solved the problem - Pearson when I spoke to them say they have never had this problem before.

Anyone any ideas? Oh...running free wheel if that matters.

I'd change your sprocket and chain, and check and set alignments properly with the new kit.

Is it running singlespeed (freewheel)? Mine does this too - current thinking is that my problem is a combination of the chainring being out of round, the freewheel being wide and pushing the chainline out, and a shit set of track nuts that can't be tightened hard enough to stop the wheel slipping under pressure. Going to try a chain tug on mine, see if it helps...

the cog may have a bent/damaged tooth causing it to jump. change it right away and you should be ok

It's God, punishing you for coasting. Ride fixed...ALL the time. Will sort the problem right out ;O)

Wow - guys, thanks for your advice, this means when I go to Pearson's Saturday I have some ideas up my sleeve. Whatever the outcome at £600 new I hope they take it on the Chin and sort it for free...

And MARIE...yes I am running freewheel so you make three people with the same problem...

Thanks again everyone.

It's God, punishing you for coasting. Ride fixed...ALL the time. Will sort the problem right out ;O)

Ha ha...was planning on getting a third bike fixed, about time I gave it a shot...

Ha ha...was planning on getting a third bike fixed, about time I gave it a shot...

THAT'S THE SPIRIT!! And my teachers said using humour to mask my ignorance would never get me anywhere. Pah!

Sorry when I said mine I meant my singlespeed (a Bob Jackson), not a Pearson. Same problem though...

Is the rear wheel staying in position? Like it's not creeping forward slowly due to the axel bolt not gripping the drop outs tight enough?

Wow - guys, thanks for your advice, this means when I go to Pearson's Saturday I have some ideas up my sleeve. Whatever the outcome at £600 new I hope they take it on the Chin and sort it for free...

And MARIE...yes I am running freewheel so you make three people with the same problem...

Thanks again everyone.

They're good people in there, they've done plenty of little jobs for me for nominal fees. Just don't purchase one of their fixed cogs, they're shit.

That's the same as what happened with the genesis fixie innit? The chainline was correct for the fixed sprocket but not the freewheel (or vice versa, I can't remember - theres a thread on here about it)