Chain slipping on cassette under load

[Dec66]

On my BTwin, following a recent cassette & chain replacement, the chain is slipping on the cassette when put under load (so, for example, if I'm in too high a gear pulling away from a junction). It's as if the chain is trying to rip itself off.

LBS have adjusted grearing, cable tension etc., to no avail. He reckons it's a freehub issue, which would be annoying as the wheels and hubs (Shimano R501) don't have that many miles in them.

Would a freehub body replacement do the trick, or is it a new wheel for me?

 

[Threevok]

Last time I had this problem after replacing both the chain and cassette, it was a worn chainring causing the problem

Is it happening on every chainring ? (assuming you have a double or triple chainset)

 

[Dec66]

It's a triple, but I rarely use the inner and middle rings.

I'll try it on those and see what happens.

 

[Rooster1]

Chainring most likely

 

[Yellow Saddle]

Cassette, most likely. But lets have a good side-on picture of that chainring. Chainrings do slip if they are very, very, very worn. Cassettes slip if a new chain is fitted to an old cassette or, if you have had a significant change in terrain where you are suddenly using a gear you have not used in many hundreds of miles. In other words, the used gears wear with the chain but when you suddenly use an unused one, the chain doesn't mesh with it.

It could of course be the freehub, but they don't fail like you've described. They slip before power is applied, now during applied power.

 

[Dec66]

Cassette, most likely. But lets have a good side-on picture of that chainring. Chainrings do slip if they are very, very, very worn. Cassettes slip if a new chain is fitted to an old cassette or, if you have had a significant change in terrain where you are suddenly using a gear you have not used in many hundreds of miles. In other words, the used gears wear with the chain but when you suddenly use an unused one, the chain doesn't mesh with it.

It could of course be the freehub, but they don't fail like you've described. They slip before power is applied, now during applied power.

New chain, new cassette.

Pics later.

 

[I like Skol]

Is it the right chain for the cassette? No chance a 6/7/8 speed chain has been fitted to a 10 speed bike is there?

Chainrings do slip if they are very, very, very worn.

I have witnessed this 1st hand on a ride with @dan_bo when his drivetrain started slipping. After the 2nd or 3rd incident I had a look and spotted the shark fin teeth on the chainring. Once it happens the first time it doesn't take much to do it again.

 

[dan_bo]

Is it the right chain for the cassette? No chance a 6/7/8 speed chain has been fitted to a 10 speed bike is there?


I have witnessed this 1st hand on a ride with @dan_bo when his drivetrain started slipping. After the 2nd or 3rd incident I had a look and spotted the shark fin teeth on the chainring. Once it happens the first time it doesn't take much to do it again.

A season of cross'll do that.

 

[Dec66]

Is it the right chain for the cassette? No chance a 6/7/8 speed chain has been fitted to a 10 speed bike is there?


I have witnessed this 1st hand on a ride with @dan_bo when his drivetrain started slipping. After the 2nd or 3rd incident I had a look and spotted the shark fin teeth on the chainring. Once it happens the first time it doesn't take much to do it again.

8 speed cassette, suitable chain.

 

[I like Skol]

A lifetime of neglect'll do that.

FTFY

 

[davidphilips]

Could there be a tight link on your new chain? Lots of pictures please and i am sure Yellow saddle will find the solution for you.

 

[dan_bo]

FTFY

Oh go and polish yer headset

 

[Dec66]

Outer chainring, looking more "peaky" than "shark finny"


Cassette

 

[gbb]

Big chainring definitely wants replacing.

 

[I like Skol]

I thought you said new cassette? Cassette looks decidedly used to me, look at the burrs at the working edge of each tooth. Chainrings are dead! Big ring and small ring should have been changed long ago. Strangely the middle chainring doesn't look as bad, maybe you should use it more.