Occasional Chain slip

[Andy in Germany]

I've noticed an occasional slip of the chain on my commuter bike; it doesn't seem to be in any particular gear. I'm guessing it's because the chain and cassette are worn after a winter of daily commuting, and the only real solution is replacement, but is there another possible reason?
Also, how urgent is it, does this sort of thing deteriorate rapidly or can I put it off for a few weeks?

 

[Darius_Jedburgh]

Sounds like chain. Try just a new chain. You might be OK without a new cassette. Chains are cheap enough.

 

[boydj]

May need a new cassette as well if the worn chain has been on there too long.

 

[si_c]

I'd get it done sooner rather than later, don't want to faceplant if the chain slips when you're putting any significant power down, like at a traffic light or anything.

 

[Blue Hills]

I'd get to the bottom of it pronto - a slipping chain won't be doing anything any good.
Have you measured the chain for wear?
I'd first change the chain anyway (hanging on to the old one for a while if measurement seems to say that it's OK) and see if that makes any difference.
If not, get on a calm bit of road with some gradients, practice changing and try to isolate the issue.
I had what I thought was slipping on the cassette - turned out to be the middle chainring of a triple. Newish chainset so maybe a manufacturing fault. I changed the ring and all was sorted.

Please report back.

 

[Andy in Germany]

Thanks. I've ordered a new cassette and chain, as from experience a new chain tends to slip constantly on an old cassette.

It'll be a week or two before I can get bike and tools in the same place to change them though so I'll have to nurse the bike for a bit...

 

[Blue Hills]

You being in germany with excellent suppliers like rose,must admit to being a tad surprised that you don't have a few cassettes and chains laid by.

 

[Andy in Germany]

You being in germany with excellent suppliers like rose,must admit to being a tad surprised that you don't have a few cassettes and chains laid by.

Hehe. Being in Germany with excellent suppliers like Rose means I got out of the habit. Especially as I'm currently in a tiny flat.

 

[gbb]

As its occasional and in any gear, freehub is screaming out to me.

 

[Lee_M]

I'd get it done sooner rather than later, don't want to faceplant if the chain slips when you're putting any significant power down, like at a traffic light or anything.

This so much. You wouldn't want to have to have emergency dental work after face planting when your chain jumps and locks your bike.

It is (a) painful and (b) expensive

Yes I did do it.

 

[Andy in Germany]

As its occasional and in any gear, freehub is screaming out to me.

Which bit of the freehub? Internally or the connection to the wheel or cassette?

 

[gbb]

Internally, you'll likely ne er see anything, they effectively sealed units, the pawls may be either sticking or slipping inside.
It only generally happens as you apply load (IME)...unless it fails altogether, then your cranks just dont drive the wheel at all.

 

[Andy in Germany]

Internally, you'll likely ne er see anything, they effectively sealed units, the pawls may be either sticking or slipping inside.
It only generally happens as you apply load (IME)...unless it fails altogether, then your cranks just dont drive the wheel at all.

Hmm... I'll start with the chain + cassette as that's probably several years old so will need replacing anyway, but it's really good to have that extra knowledge if it doesn't work...

Also, I wasn't putting a lot of pressure on the pedals usually (because I'm far too lazy) so it wasn't generally "under load" when slipping.

 

[battered]

You can tell whether it's chain slip or the freehub letting go, because chain slip gives you an obvious grating noise whereas a slipping freehub just spins round but the chain obviously stays in engagement with the gears.

 

[Andy in Germany]

You can tell whether it's chain slip or the freehub letting go, because chain slip gives you an obvious grating noise whereas a slipping freehub just spins round but the chain obviously stays in engagement with the gears.

Trouble is it happens very occasionally and only slips slightly so by the time I've noticed it and stopped looking a the scenery, everything is normal again.