Chain and cassette wear

markhewitt1978

Back in September I fitted a new chain and cassette and I've ridden them through the winter, clocking 1,300 miles on the chain. At the start of March I changed back to my summer wheels and put a new cassette on, but didn't change the chain as I'd intended the bike shop to do it when I got it serviced.

Well I got it serviced last weekend and they've told me that the cassette (Ultegra 6700) which has done no more than 250 miles, is badly worn and will need replacing soon. I've no doubt that's accurate so I suppose it's down to wear from the chain which apparently was well worn?

So is the lesson here don't put on a new cassette without a new chain? But putting on a new chain on an existing cassette is probably less of an issue?

slowbike

yup - if you're replacing a worn cassette then replace the chain at the same time. You can go through a few chains with one cassette if you replace them before they're too worn.

DiscoBoy

You (they) have hit the nail on the head. If you put a new cassette on and your chain is worn, it'll wear your cassette very fast.

A chain wear checking tool is a good investment.

markhewitt1978

The new chain was skipping about a bit, I think because of the worn cassette, I shall suck it up and replace the cassette and do things the correct way around next time!

Moonbiker

Well I got it serviced last weekend and they've told me that the cassette (Ultegra 6700) which has done no more than 250 miles, is badly worn

Are you sure they aren't just trying to sell more stuff?


Hard to believe something is bady worn in 250 miles.

So teeth look abit like this pic?

mattv

The higher spec cassettes are lighter so materials can sometimes be softer or more prone to wear, so chances are if it wasa tiagra or 105 ccassette it'd have been ok. You get some obvious, nearly unrideable, signs of a badly mis matched cassette and chain normally. 1000 miles difference of mileage isn't that great in my opinion, unless you pour engine oil on as lube or stomp everywhere in a 53/11 gear.

markhewitt1978

mattv wrote:

1000 miles difference of mileage isn't that great in my opinion, unless you pour engine oil on as lube or stomp everywhere in a 53/11 gear.

I do but I change down to 53/12 if it's above 20%

To be fair, the chain was run all through the winter often in poor conditions so I was entirely unsurprised to learn it was worn, but didn't think 250 miles with the new cassette would have done the damage. Although I do have a tendency to cross chain which doesn't help I suppose.

iron-clover

I would personally put your new chain onto the old cassette and see what happens- if you find it skips or jumps and can't stop it through adjustment, then yes, your cassette needs to go.
I am also skeptical as to whether 250miles could wreck a cassette, but I guess it is a fairly long time for a very worn chain to work it's mischief.

I always had the problem of letting the chain become too worn which in turn eats into the cassette and ended up having to replace both at the same time as the cassette doesn't take the new chain properly. I've invested £8 in a chain checker tool from ChainReaction and haven't worn out another Cassette since (two chains down).

markhewitt1978

iron-clover wrote:

I would personally put your new chain onto the old cassette and see what happens- if you find it skips or jumps and can't stop it through adjustment, then yes, your cassette needs to go.
.

That's what they did, new chain on 'old' cassette. When under load going up hill or putting in some power on the flat it was ok, but putting in little effort down hill it was skipping around all over the place, sometimes having to shift 3 or 4 times before it found a gear it was happy with.