Intermittent Chain slip

[Andy in Germany]

I'm starting to get intermittent chain slip on my tourer; it's just occasional at the moment and feels like when he chain jumps between gears. Is this the harbinger of a worn chain or something else?

 

[Cycleops]

Classic symptoms for a worn chain but check the cassette and chain ring too.

 

[wafter]

As above, check the chain with a proper tool (the Shimano one is good, most other designs are flawed in the way they measure), by hanging next to another new one and checking the difference in length of the same number of links, or by using a decent steel tape.

Checking cassette and rings is harder as there's no quantitative method I'm aware of - just have to look for obvious, visible wear (such as change in too shape) or fit a new chain and see how it behaves.

How many miles are on all the bits?

 

[Andy in Germany]

Thanks for that. I figured as much but I'm aware sometimes different problems show similar symptoms, and I wanted to be sure.

How many miles are on all the bits?

Now you come to mention it, a fair few. I'm estimating here, based on my commutes in recent years, but it's probably in the region of 8000 km or 5000 miles.

 

[Broadside]

My vote is for sticky freehub pawls. It’s hard to work out if it is that until it gets quite bad.

 

[Illaveago]

Is it in all the gears I'm assuming it's a derailleur?
It happened on a friend's bike in one gear. I found that the sprocket had very slight wear.

 

[Illaveago]

My vote is for sticky freehub pawls. It’s hard to work out if it is that until it gets quite bad.

And painful!

 

[Paulus]

I'd go for a worn chain, and/or sprockets. If you have a look at your most used, favourite gears at the back and check the profiles of the teeth.

 

[ebikeerwidnes]

I have had this a few times - and it has always ended up being worn stuff - chain and gears basically

But dirt and muck make it worse so a damn good clean of the chain and gears, followed by a good dose of clean oil can help put off changing the stuff

Works for my ebike anyway - and, of course, mid drive ebikes do create a lot fo wear on chan and, normally, one specific gear

 

[Chief Broom]

or it could be the derailleur
https://www.cyclechat.net/threads/the-slip.293577/

 

[roubaixtuesday]

it's probably in the region of 8000 km or 5000 miles.

That's a long way for a chain that's used in all weathers. Worth replacing regardless of symptoms IMV.

Assuming it's slipping on the same gear (rather than skipping to the next gear, it can be hard to differentiate) will definitely need to replace cassette and maybe chainring(s) too. Jockey wheels can make a big difference too.

The drivetrain on my commuter is totally borked after the winter, but will hold out a few weeks before replacing the lot as spring arrives.

 

[Cycleops]

Now you come to mention it, a fair few. I'm estimating here, based on my commutes in recent years, but it's probably in the region of 8000 km or 5000 miles.

You're living on borrowed time then Andy.

My vote is for sticky freehub pawls. It’s hard to work out if it is that until it gets quite bad.

That will sound like sharp 'crack' if it is. Chain slip will be more graunchy. The former can usually be sorted with a spray cleaner or maintenance oil. But given the mileage my money is on worn drive components.

 

[Ajax Bay]

You will need a new cassette/block too, remember.
Wrt comments above:
"sticky pawls" - negligible chance (symptoms)
"check the profiles of the teeth": waste of time
"could be derailleur" - this chain is slipping not skipping, so 'no'
OP is shifting into one of the less used* sprockets and applying (or maintaining) power: well elongated chain is felt slipping.

* I am assuming this chain and cassette have been allowed to age together (ie this is not the second or third chain on the cassette). The elongated chain has worn the well used sprockets 'to match' so they are OK: but the less used sprockets, not. Welcome discussion on this 'cos I'm not sure my assertion is valid.

 

[Alex321]

You will need a new cassette/block too, remember.
Wrt comments above:
"sticky pawls" - negligible chance (symptoms)
"check the profiles of the teeth": waste of time
"could be derailleur" - this chain is slipping not skipping, so 'no'
OP is shifting into one of the less used* sprockets and applying (or maintaining) power: well elongated chain is felt slipping.

* I am assuming this chain and cassette have been allowed to age together (ie this is not the second or third chain on the cassette). The elongated chain has worn the well used sprockets 'to match' so they are OK: but the less used sprockets, not. Welcome discussion on this 'cos I'm not sure my assertion is valid.

Well he doesn't actually mention that it is in the less well-used sprockets.

So it could just be the chain, if he is lucky. That is a lot of miles for a chain, from what he says.

 

[wafter]

Now you come to mention it, a fair few. I'm estimating here, based on my commutes in recent years, but it's probably in the region of 8000 km or 5000 miles.

Sounds like a pretty good innings really for a "typically" maintained chain.

For reference the chain in my old road bike started skipping at a similar mileage; that was when I didn't know any better about maintenance and it just got the odd oil top-up occasionally. Replaced the chain and the IIRC it continued to skip as this had also knackered the cassette so this was done too.

Safest route is probably to buy a replacement chain and cassette, clean it all up, fit the chain only to see how it goes; fit the cassette if necessary and if not keep it as a spare