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Whilst pedalling my bike has suddenly started dropping the chain in any of the 3 lowest gears
The DUB bottom bracket had play so I replaced it but that didn’t help
Further info’
I can easily recreate the problem with the bike upside down. A narrow tooth on the chain ring misses the gap between the plates and the chain falls inside the chain ring. It doesn’t seem to happen at a particular point on the ring or chain. The chain and ring appear undamaged. It’s all a bit sticky with old Squirt. It’s the Second chain on the bike worn between 0.5% and 0.75%.
I assume a new ring and chain will solve it. But I’d like to understand what has gone wrong and be sure that all I need is a new chain and ring.
What happens when you properly degrease the chain?
Is the mech moving smoothly and providing enough tension at that point? Might be worth degreasing the pivots on that too.
Bent or out of align tooth on chainring will do this, give it a spin without chain and visually check they are all straight.
The mech has lots of tension and I couldn’t see a bent tooth with no chain on
I think I might have to clean the chain😔
My bet is on a singular tooth being slightly bent. Try and locate it and sraigten out
My currrent thinking i that the tooth has gone on to damage the chain in places. It is't always coming off on the same tooth. I think i have to replace the ring as that could go on to damage the new chain. Lucky those steel rings are a sensible price, although of course they hace still nearly doubled in price. I'll also check spacers to make sure I haven't mucked up the chain line
Thanks folks