New chains/cassettes? (worth it or not?)

bobgfish

So, just cleaned the gunk of the bike for the umpteen time this winter...

I've done 1 KMC chain, 1 Shimano and now on the third Shimano all on one cassette with about 6000Km's gone by. Only use the 39 tooth front chain ring for 95% of the time

I swapped the first two when the chain gauge said time to replace. It's at that time again and I've got a new cassette and new chain. It got me thinking that even though the chain is worn it's not really slipping at all. The third chain did slip a little for the first few rides on this cassette but then bedded in without issue. It's also really only the 15th,16th tooth cogs that are worn.

Got me thinking that maybe I should just leave the thing on and see what happens. I can't see the new chain working well with the old cassette this time so what have I got to loose?

PhilofCas

I've done that on my (old) MTB, just left them both to wear out together, not had a problem so far, though I realise the chain is getting weaker and weaker and at some point it will break, so that's a concern, but I don't do anything serious on it these days, it's more of a bike to ride very locally on, just pottering about with the kids.

So not sure whether to recommend doing on a road bike on safety grounds???, pretty sure it'll work but for how long? and with reducing reliability/safety.

Hope that helps

keef66

You could just leave them on to wear out together. The chain breaking won't be a problem, but at some stage it will start to skip on the sprockets you use less frequently, then you'll have to replace the lot. I'm not sure how often you could do that before you'd have worn the chainrings too. Mind you, it sounds as if you ride like me, most of the time on the middle ring of a triple? Not too expensive or difficult to replace the middle chainring.

Coincidentally I fitted my 3rd chain last night. Replacing once I get to 0.75% on the chain wear checker. Original chain was 105, but have since gone for whatever 10sp chain CRC are selling cheapest. Last nights was a Mavic which cost a tenner; it seemed very quiet on the workstand, but occasionally reluctant to shift up the cassette. I'll see tonight if the shifting is acceptable on the road.
I might be shopping for a 105 chain tomorrow. Anyone know who does them cheapest at the mo?

CarlosDSanchez

A bit of a faff maybe, but I buy 3 chains together and swap them over every 2 or 3 weeks and run the whole drivetrain until it starts slipping. I do quite a high milage though (200 or so per week) so it might not be worth the bother for you.

bobgfish

How much milage do you get from three chains when swapping? I've done 6000Km on the three used one after the other but not swapped in between. I do about 300KM a week (actually a lot more recently) Seems like KMC chains last longer than the shimano's (my one sample) but are a bit noisy. Got a new KMC to try after this set and a 105 cassette block is only about 35 euros. Wondering if's it's cheaper to ignore the chain measurement devices and when it starts slipping fit a new chain and a new cassttte. When I was a kid I recall having a 5 or 6 speed and chain and basically only every getting a new chain when the old snapped. Times have changed.

rake

bobgfish wrote:

How much milage do you get from three chains when swapping? I've done 6000Km on the three used one after the other but not swapped in between. I do about 300KM a week (actually a lot more recently) Seems like KMC chains last longer than the shimano's (my one sample) but are a bit noisy. Got a new KMC to try after this set and a 105 cassette block is only about 35 euros. Wondering if's it's cheaper to ignore the chain measurement devices and when it starts slipping fit a new chain and a new cassttte. When I was a kid I recall having a 5 or 6 speed and chain and basically only every getting a new chain when the old snapped. Times have changed.

use a ruler to measure the chain. it will give a better indication. use 2 or 3 per cassette and then let it wear out.

CarlosDSanchez

Am up to 6000 miles on the commuter and 1000 on the road bike.

I also have issues with shimano chains, no quick link and the ultegra one fitted to the road bike broke at only 50 miles leaving my arse in the breeze in the middle of a 3 lane roundabout.

I bulk buy the mavic 10spd chains off crc, come with a quick link, seem pretty hardy and at £9.50 a pop they're a bargain. I'm hoping to get 10000 miles or so out of the drivetrain doing this and seem to be on track at the moment.

TuckerUK

If you use a chain gauge other than the £40-50 Shimano one, you are measuring roller wear too, which is pretty inconsequential.

Use a ruler instead.

Here's a link to a page which explains it fairly well:

http://pardo.net/bike/pic/fail-004/000.html

keef66

well I can now report back favourably on my 10 sp Mavic chain with my otherwise 105 drivechain. Pretty quiet, and shifts as well as the Shimano original. Think I'll be shopping for them in bulk to save even more!