I assume I need a new cassette? Chain slip under load

holiver

I have been experiencing chain slip under load for a little while now so I purchased a KMC chain measuring device and a new KMC X10.93 chain for my Kinesis.

The measuring device confirmed the chain was worn so I replaced it. However, with the new chain fitted with what I believe is the same number of links as before, the chain slip is now much worse and happens under load in almost every gear. I'm assuming that the old chain and cassette (a BBB BCS-10C) wore together and now the new chain does not sit right upon the cassette?

Does the chain length look OK in these pictures? That is the only other variable I can think of...

k-dog

Yep, it'll be the old cassette/new chain combo. A new cassette will sort it. in the future changing the chain earlier makes the cassette last longer - you can get at least 3 chains to a cassette.

Spatulala

A new cassette will hopefully sort it. First time I ever replaced a chain it wasn't just the cassette that was ruined it was also one of my chainrings. The bill made me much more attentive to chain wear ever since!

holiver

Thanks guys, I will certainly pay more attention to chain wear in the future!

Here is a picture of the cassette teeth and what they look like direct from the factory, albeit not using the best angle.





In any case I think I will go for a Campagnolo Centaur 10 speed cassette instead of a cheaper alternative and treat it well.

sungod

btw the simplest way to measure a chain for wear is with a 12" ruler, 12 links of a new chain will have pins located 12" apart, as wear occurs this increases

no need to count links, you can just hold the ruler to the chain with the zero mark on one pin and see where the closest pin is to the 12" mark

rule of thumb is fit a new chain once the distance increases by 1/16", by the time it reaches 1/8" the cassette will probably skip with a new chain especially on the most used sprockets

keef66

Your chain looks a bit long; in the final pic in small / small combo the mech is folded back on itself. Try it a link shorter at least.

Cassette wear is frequently impossible to spot visually, and the first sign is a new chain skipping under load, especially if the old chain was allowed to wear significantly before replacement. Sometimes this will settle down as the components wear together; I generally try a new cassette and it solves the problem.

Some people just run the same chain and cassette until something breaks, then replace the lot, arguing that all this chain checking leads to perfectly good chains & cassettes being discarded...

dowtcha

How many miles on your first chain?

Guernsey Donkey

It's difficult to see from just a photo but to me those chainrings look more worn than the cassette (especially in pics 3 & 4).

keef66

Guernsey Donkey wrote:

It's difficult to see from just a photo but to me those chainrings look more worn than the cassette (especially in pics 3 & 4).

You're right; they do look a bit pointy. Could easily be the cause of the skipping...

Just how old and how worn was the chain??

itboffin

That cassette looks fine too me and others have said your chain is too long, take one full link out and perhaps even two if there's excess before buying a new cassette.

Bozman

I've had chain slip under load twice and on both occasions I think it was down to a stiff link. New KMC chains on low mileage cassettes, they tested fine until the drive chain was under load, I cleaned the chain, relubed and on both occasions this cured it.

itboffin

Oh I just noticed that's a BBB cassette as well, I'm 100% sure your chain is too long and that brand of cassette is in my experience crap, I broke two sprockets in half and several teeth off another, as much as I'd like to say its down to my awesome power, it's not.