New chain skipping question

chuckcork

Just had a chain break on me last week, so thought that with minimal mileage done on bike, less than 4,500 km, I'd just put a new chain on rather than re-use the old one, which was pretty close to overstretched anyway, as the gears etc should still be good enough to not worry about skipping.

But out riding on Sunday on my first ride with the new chain, I was finding that while on my big chainring everything was meshing correctly, on the small ring for climbing hills it was skipping quite badly, pretty much useless in fact.

What is happening here?

Looking at the rear sprockets they don't seem to be that worn out (they are Shimano 105's), is it more likely the smaller chainring is more knackered than the big chainring and that is what is throwing things out?

Or less knackered?

I'm confused, but I don't really want to spend around £100 on a new cassette and chainrings if simply replacement of one part would be enough.

Any advice would be a big help, I'd take it to a LBS for advice but don't really expect to be told anything other than replace the lot!

bobtravers

Some questions:

Did you use the same length of chain than the old one?? If stretched, you might have put it a link or 2 too long?

Is it skipping on all positions of the crank or only in one position?

Does teeth on your small chainring looks damaged or not??

Good luck??

The Spiderman

Did you measure chain stretch on the old chain with a chain checker?
I recently replaced rings and chain on my mtb.The cassette was fairly new anyway,so it stayed put and chain stretch on the old chain was only 0.75 on a park chain checker, but I thought it best to replace the chain at same time as the rings.(Chains are cheap)
So new rings and chain maybe OK,with a slightly older cassette,assuming the old chain wasn`t overly stretched before replacement and causing premature wear to your cassette.........
Sounds like you may only need the inner ring........
Worth a go,I`d say,but check and rule out indexing and chain length problems first!

chuckcork

Checked out the old chain using a Park tool I have, the old chain (off the bike) was longer than the replace now index.

On the gears all of them feel fine on the large ring, but on the smaller ring every one of them can't handle any amount of load, I guess I should just replace that ring and that would do it? They actually all look ok and not too worn.

Any recommendations for a replacement though as that seems to be what I am working towards? The website I got it from, Spacycles, quotes it as being part of a "FSA CK-C6020 alloy 50/34t silver", I had thought of upgrading to Ultegra but they don't seem to make them that small? The one I've seen is this: http://www.chainreactioncycles.com/Mode ... elID=18486 , any advice on wether that would work with what I have? Extra leg strength may be required but I guess I'll just develop it!

The bike is a Dawes Audax Supreme if that makes any difference, details here: http://www.spacycles.co.uk/products.php ... _-_Tourers

John.T

First find out if the chain is slipping on the cassette or the chain ring. No point in throwing money at the problem until you know where the fault lies. At 4500km it is unlikely the ring will be badly worn. Even a worn cassette at this mileage is probably the result of poor maintainance. I would expect to get at least this on the winter bike which gets blathered every ride.
If it is the chainring you need a 34 tooth 110 BCD ring. Spa can supply these from both Stronglight and TA. Other makes are available but not as easy to find.

gandhi

If you use the same chain for a lot of miles, you'll wear the cassette and chain rings in line with chain stretch. You'll probably need to replace your cassette and maybe a chain ring (probably the small one, it wears more easily) or two.

I try to replace my chain more frequently than that, as it saves having to replace cassettes.

pbracing

Did you re-do the gear indexing on the rear derralier? It can sometimes need doing even if just the rear wheel is taken out as it's allowed to move right accross without using the shifters.

I've found that the chain then slips only on the inner chainring for some reason. Re-indexing then sorts it.

Could be a worn front ring or cassette though. If you pedal hard on big ring does it slip? Should do if i's the cassette. :?

chuckcork

John.T wrote:

First find out if the chain is slipping on the cassette or the chain ring. No point in throwing money at the problem until you know where the fault lies. At 4500km it is unlikely the ring will be badly worn. Even a worn cassette at this mileage is probably the result of poor maintainance. I would expect to get at least this on the winter bike which gets blathered every ride.
If it is the chainring you need a 34 tooth 110 BCD ring. Spa can supply these from both Stronglight and TA. Other makes are available but not as easy to find.

Actually John I use a reasonable lubricant and try and clean the chain every couple of weeks (if I have the time) to keep the crap level down, and do a minor mechanical checkover at the same time if not every week before a Sunday ride.

Since my rear mech broke off well before its time I've been a little paranoid about the setup and rarely take it to a shop and now try and do my own checks within the limits of my knowledge which is steadily extending in any case.

(You remember that rear mech, don't you? My other bike with its Sora shifter has done in excess of 13,000km in 18 months so far compared to the 650km in 6 weeks the one sold did. Has since cost the certain store in Harrogate ££££ in lost sales as I went elsewhere for rather a lot of gear after wards)

chuckcork

pbracing wrote:

Did you re-do the gear indexing on the rear derralier? It can sometimes need doing even if just the rear wheel is taken out as it's allowed to move right accross without using the shifters.

I've found that the chain then slips only on the inner chainring for some reason. Re-indexing then sorts it.

Could be a worn front ring or cassette though. If you pedal hard on big ring does it slip? Should do if i's the cassette. :?

Thanks for the suggestion, but the indexing seems OK as it is just slipping, riding last night reasonably hard for about 18 miles I think it maybe just slipped slightly when on the big ring maybe twice and not at all badly, and that could be indexing in any case.

If nothing else I could just order a new ring and see how it works, if I need to change the cassette as well then I guess these things happen.

John.T

Not getting at you. Sorry if it sounded that way.The mileage is low so there must be some reason.
The comment to check which end is actualy slipping is valid anyway. It is also very unusual for ALL cogs to be worn to the extent of slipping. It could well be indexing as only a small amount out will cause the chain to try to climb off the cog. It was happening to one of my riding group yesterday and he was on nearly new Ultegra SL. A quick tweak of the adjuster cured it. His slip was only on the big ring and 2 larger cogs. It is always cheaper to sort out all possible things that do not cost anything before spending any money.

fossyant

10p on new cassette !

ansbaradigeidfran

fossyant wrote:

10p on new cassette !

Is that a bet or a spend? :P

andy advanced

well as a chain stretches it starts to wear the cassette and chainrings so if you've done 4500km id say your chain was stretched past the point of safe replacement, there is a tool out thare that measures chain stretch, your looking at a new cassette at least i'd say
fingers crossed for you.

John.T

All you guys must be a chain manufacturers gift from heaven. I am still running my first 10sp chain from early 2005. It is an Ultegra one running on Ultegra cassette and is only used in summer. It has done around 9000+ miles and is still well within limits. It gets cleaned with car shampoo after any dirty rides and degreased and relubed about once a month.
My winter bike gets a new chain around October time and will be abused (I do clean and lub) until I think the bike can be rested for the summer. The whole bike then gets a thorough overhaul and a new chain. If there is any slip also a new cassette but using Ultegra cassettes I usually get it to run 2 winters. I have only had one chain failure in 12 years (about 36000 winter miles) and that was my fault for seeing if I could get 2 winters from one chain. It broke in January. Lesson learnt. Keep it clean and lubed, change it when it gets to its wear limits and you should have no problems.
Also we should not talk of chains stretching. They wear the pins and inside the rollers. They do not stretch.

jumbolugs

Maybe your new chain just needs time to bed in. I had this problem last time I replaced my chain - new one slipping a lot - problem went away after about 2 weeks (150-200 miles).

Have to say it is a cheap "Taya" chain from Halfords - with a supposedly "rust-proof" coating on it - which may have had something to do with the slippage.

chuckcork

John.T wrote:

All you guys must be a chain manufacturers gift from heaven. I am still running my first 10sp chain from early 2005. It is an Ultegra one running on Ultegra cassette and is only used in summer. It has done around 9000+ miles and is still well within limits. It gets cleaned with car shampoo after any dirty rides and degreased and relubed about once a month.
My winter bike gets a new chain around October time and will be abused (I do clean and lub) until I think the bike can be rested for the summer. The whole bike then gets a thorough overhaul and a new chain. If there is any slip also a new cassette but using Ultegra cassettes I usually get it to run 2 winters. I have only had one chain failure in 12 years (about 36000 winter miles) and that was my fault for seeing if I could get 2 winters from one chain. It broke in January. Lesson learnt. Keep it clean and lubed, change it when it gets to its wear limits and you should have no problems.
Also we should not talk of chains stretching. They wear the pins and inside the rollers. They do not stretch.

Possibly bicycle chains don't, but I remember the chain on the CB500 I had years ago certainly did, regular lubrication using a good lubricant could reduce it to nothing as opposed to a heck of a lot with a poor lubricant, both sitting on the same shelf in the motorbike dealers shop at the same price!

I have a Chain stretch indicator BTW, old chain (off the bike) now shows as being >1%, new one shows about .25<>.5%.

Guess I'll try the indexing first as suggested, cheaper than buying a new set of parts and throwing away barely used ones.

pbracing

What he meant was chains aren't elastic. They get longer because of increasing tolerances due to wear.

Let us know how it goes with the indexing. Be patient, even if it means doing it a few times to fine tune it. It's alway better than slipping gears out on the road.

Anonymous

I had this problem, after about 4000 miles I needed a new chain, and I got a new SRAM chain fitted and it was nothing but skipping, was a nightmare, a new Cassette solved the problem here.