Old chain replaced but now new one skipping here and there ?

[deano69]

Does this mean I need a new front 3 ring crank set and new 8 speed cassette or would I get away with something easier baring in mind the bike 7 yrs old and has the original 3 ring crank set on which i was told was ok last week by bike shop but dont seem to be ??

The 1 on bike is a cheap non branded one I think with fixed and non replacable rings and runs on a tapered square drive bottom bracket the rear cassette is only a year old and a shimano 8 speed and rear derailleur is shimano Altus with oversized jockey wheels.

New chain is 8 speed KMC z narrow same as original but up until last week was running a very worn but stetched shimano HG40 with no skipping as obviously worn and bedded to old chain rings but new one skips now and then in certain gears....very annoying....

I only changed it thinking a new one will be fine and old one is worn and very tatty and looking worse for wear with a tiny amount of rust...

Anyway would very much appreciate any help and advice on this problem,

Cheers, Deano

 

[musa]

You need to adjust the dérailleurs now by getting a screw driver and twisting the limiting screws

 

[musa]

watch this should help

 

[Tim Hall]

More likely to be the cassette that is worn than the chainrings, although in your case the cassette is only a year old. I guess it depends how hard the cassette teeth are and how badly worn the chain was. I take it the chain wasn't changed when you changed the cassette last year.

Which gears does it do it in? All on a particular chain ring or just some? If just some, it's more likely to be the cassette.

IME it's more pronounced on the smaller sprockets, presumably because fewer teeth are engaged in the chain anyway.

Having said all that, I've just replaced a cassette and chain and found that my middle ring is worn as well, so it slips when giving it welly.

 

[ColinJ]

And when that doesn't work - change the worn out bits!

Despite knowing about this problem with new chains replacing very worn ones, I made the same mistake recently. The old cassette looked okay, but the chain was slipping every few pedal strokes. I changed the cassette a couple of days ago but not the rings. On a long forum ride yesterday I was still getting the odd slip of the chain so it looks like new rings are required too!

It reinforces the advice to change chains before they wear enough to wreck the rest of the transmission.

 

[deano69]

Thanks for advice everyone, I have ajusted deraileur to no effect it still does it mostly on smallest and middle front chain rings its worse when giving it some welly especially if you're standing up pedaling as it feels like you will end up slipping and crushing something on the cross bar

I found this online..http://www.woollyhatshop.com/Cranks...-Crankset-42/34/24-170mm-BLACK/prod_4302.html... but even though is fairly cheap i dont want to change unless I really have to but its seems like the slipping and skipping is on the front rings rather than cassette which seems to run fine and smooth with the new chain....

Im ok at setting gears and all types of maintenance and have all required tools for doing so crank arm extracors, bottom bracket tool and cassette tightening tool etc plus it saves ever more expensive bike shop repairs I cant really afford now I been made redundant again

 

[cyberknight]

I would change the cassette 1st , its more likely to be the the ratios that you used the most that are worn and chain rings generally last longer that cassettes .

 

[Red Light]

Agree. Its almost certainly a worn cassette that is your problem. Try replacing it and see if that fixes it. Its very unlikely to be the chainset and more likely to be to do with the variation of the chainline on different rings making it more or less prone to skip on the rear.

Or given the circumstances you could just put the old chain back on and run it until it stops working. A little bit of rust on the chain won't be a problem. Just keep it well lubed and any rust will quickly wear off in use.

 

[Red Light]

You need to adjust the dérailleurs now by getting a screw driver and twisting the limiting screws

The limit screws won't do anything for this problem. All they do is stop the chain going off each end of the cassette into the spokes or the dropout. If the gearing was misadjusted, adjusting the barrel adjuster on the cable will help bring them back into adjustment but the symptoms there are clattering from the chain as it tries to change up or down from the cog its on, not slipping.

 

[deano69]

Thanks for the advice everyone I will get local shop to check cassette for wear 2 moro and poss find the problem as they dont charge to look only to fit new parts which I can do no problem