New Chain = New Cassette?!?

[Jezston]

I need a new chain. My current one is very worn and rattly through me riding in too high gears when I first started.

Popped round the local LBS's to see if anyone could sell me a chain and had a tech free to fit it that day. First two shops I went to said they could do it, but not today they were too busy. Fair enough, but I'll try the other shops if you don't mind as I'd quite like to get it fitted now if I can.

Last shop I went to, yep we can fit it right now - but we won't fit a new chain without a new cassette. It's dangerous, isn't that right colleague? Yeah if the chain is worn then the cassette is too so if you don't get a new cassette at the same time the chain'll keep coming off. That'll be £50 if you want that doing.

I said I'd think about it and I left.

Is this true? Or do I not go there again?

 

[PpPete]

Invest in a chain checking tool
if less than .75% stretch don't need new cassette
if more than 1% stretch then do need a new cassette
and most new chains come with instructions on how to fit them yourself (with a powerlink)
plenty of advice online about adjusting length

 

[numbnuts]

but we won't fit a new chain without a new cassette. It's dangerous

yeah right my bike has done over 20,000 on two cassettes and four chains.

 

[LizardEye]

If the chain has stretched beyond a certain point, it will still work with that cassette, as the cassette will have worn with it. But if you put a new chain on, the new, tighter links won't match the worn teeth on the cassette, and the chain will just slip, expecially on the smaller cogs.

If this is the case then you will need a new cassette to match the new chain. I can't see how it's dangerous, it's just either annoying, or makes the bike unrideable.

It's a very good reason for checking the chain wear regularly, as I have found to my cost.

Even six months fairly normal use can wear a chain out.

The other option is just to stay with what you've got until they wear out completely, or until you
find a cheap cassette on ebay

 

[amaferanga]

If your chain is indeed very worn then there's likely significant signs of wear on the cassette in which case a new cassette is probably required. If the cassette doesn't look very worn then fit a new chain and see if you have any problems.

I'm on the 3rd chain for a single cassette on my best bike which has done >5000 miles and I don't think I'll need a new cassette any time soon.

 

[rich p]

Is it advisable then to change the chain before it's worn out, in effect, to save having to replace the cassette?

 

[2Loose]

Is it advisable then to change the chain before it's worn out, in effect, to save having to replace the cassette?

Indeed. Preventative maintenance.
I ran a chain into the ground last year and it cost me new cassette, chain and chainset\rings.
Now I check the chain monthly because that experience really hurt my wallet.

 

[gbb]

Invest in a chain checking tool
if less than .75% stretch don't need new cassette
if more than 1% stretch then do need a new cassette
and most new chains come with instructions on how to fit them yourself (with a powerlink)
plenty of advice online about adjusting length

Even thats not guaranteed porkypete...
I fitted new chain and cassette earlier this year. Chains just done 1000 miles and the 1% indicator drops in the links. Replaced the chain, it all works fine. Yes, i probaby have worn the cassette somewhat, but its working perfectly.
It may be if someones cassette was already worn, it may not survive the 1% wear, but a new one can.

 

[Alien8]

I thought chain rotation was standard practice if you use anything but the cheapest parts.

Three chains, swap every 500miles, discard once up to 0.75% wear.

 

[Manonabike]

I thought chain rotation was standard practice if you use anything but the cheapest parts.

Three chains, swap every 500miles, discard once up to 0.75% wear.

I do something like but with only two chains and swap them every time I clean the bike, maybe once a week or fortnight

 

[Jezston]

Thanks guys, all good advice.

The guy at this LBS only briefly checked the chain. Stuck some metal device into the chain with prongs at each end - said if the prongs went all the way through it was done, but it wasn't that bad.

He didn't seem to inspect the cassette AT ALL, but him and a colleague who didn't even see my bike let alone inspect it both stated I needed to buy a new cassette, and there was no discussion about it.

I don't think I'll be using them again, as I've always felt a little uncomfortable there, and advice they've given has often been highly contradictory to what I've heard everywhere else. There is a guy who I get on with who works there, and most of them are pretty friendly, but I feel there is some kind of 'mindset' amongst the more techy people at that shop which I find disagreeable.

So what do I do next?

 

[Davidc]

Depends how deep the Jezston wallet is! The lbs advice sounds like an answer that is just safe in all cases.

My experience is the same as that of others above. I replace chains just before they're worn out (used to measure them, now use a guage with prongs either end made by Park Tools) Check them occasionally until they're worse than 75% then every week when I clean and oil them. When they're just below 100% spend £10 or so on a new one.

When the new one's on I check that it's fitting the cassette with no visible gaps (using a magnifying glass but you're younger so won't need that). If the cassette has worn I put a new one on. Next time it's going to cost me for a new chain whip and lockring tool as well - never lend tools to someone else....

I'd reckon you need to invest in a chain measurer.

The life of chains varies between people - we all ride differently. That said I used to get 1500 mi to a chain and 4500 to a cassette, but having 2 bikes I've never worn 'em out on, I'm expecting that to change.

Edit:

If you have an original chain without a removable link you'll need a splitter, or of course a hacksaw, when you come to change it.

The advantage of a splitter is that it also lets you remove links from the new chain if it's too long. (On my last bike chains were always 4 links too long.)

 

[MacB]

if it's high end kit then chain rotation and regular checking is worth it, if not I wouldn't bother. I just let chain and cassette wear out together and replace them, plus middle ring, at the same time. By my calcs it worked out the same cost as using multiple chains, but this is with mid range 9 speed stuff. Even better if you keep your eyes peeled for sale offers and stock up. I have 3 cassettes, 4 chains and 2 middle rings in the garage, all bought for less than 60% of regular price. This is only for the weekend bike so probably got 3-4 years of spares there(allowing 3k miles a year). My training, shopping, pootling miles are all done on hub gear bikes, lot less wear and tear on rings, cogs and chains with those. Same with tyres, I use M+ for general stuff, they seem to take for ever to wear out and I've never had a puncture on them.

How you ride matters as well, if you're constantly flicking through the cassette, and up and down the rings, then any wear is more noticeable. I tend to use few gears and rarely leave the middle ring so it has to get pretty worn/slippy to bother me.

 

[LizardEye]

I would fit a new chain, it's dead easy, and see how you get on. If it runs ok then you've got away with it this time, and either by a park chain checker or just measure the chain every month or so.

If the chain slips, then you'll have to fork out for a cassette as well .

IIRC to measure the chain you take a 12 inch ruler, put zero against one of the pins, and the 12 inch point should line up exactly with another pin. If it's out by an eighth of an inch or more, then the chain and cassette are probably toast. Ideally you want to change the chain when it's just more than 1/16 of an inch stretched, which roughly equates to 75%

 

[soulful dog]

Indeed.  Preventative maintenance.
I ran a chain into the ground last year and it cost me new cassette, chain and chainset\rings.
Now I check the chain monthly because that experience really hurt my wallet.  

I've just discovered this the hard way too - it was a lot more expensive to fix than I thought it would be! I did  (I did wonder why the teeth on the cassette were so much more pointy than I'd seen on other bikes    ). Which means my next bike purchase will be one of those tools to check the chain wear, as a new chain when needed seems the far more sensible way to do it!