MTB chain ring problems (I think)

[Gate closer]

Please help. The chain on my MTB seems to jump forward every now and then probably a link every full turn when it is on the middle chain ring.

Could this be due to the chain ring being more worn than the other two as I use it the most? The chain is new and the same length as the one I removed. This issue only started after the Berg and Bush and no matter how much tweaking I do I can't get the problem sorted.

[GerrieTruter]

I'm no expert but I had a similar problem on my first bike that I got 2nd hand. The chain was replaced and I had chain slip, replaced the chainrings and still had the problem. Problem was solved when I replaced the cassette. 

[Dicky DQ]

Sounds like new chain ring and cassette.

[Daniel J Méssem]

check that each link in the chain can pivot freely, easy way to do this is to move the pedals backwards slowly while holding the derailer to 'slacken' the chain, watch the chain move through the jockey wheels on the derailer

 

if there are links that do not pivot easily fix em (the place where you joined the chain is a likely suspect)

 

this is one thing that can cause a skipping chain

 

a bent chainring tooth may also cause this, maybe post some pics of the rings

 

does this only happen on the middle ring?

[Gate closer]

Yup only in the middle ring which is what made me think that it was worn but will check out the links as suggested. Thanks for the advice

[johanpre44]

I've seen some pretty worn middle rings that did not have any chain slip. Problem is usually at the cassette or chain. I suggest that you look through them properly (tooth by tooth and link by link) as suggested by Daniel. Note that worn sprockets and chain rings are very obvious, especially your favorite choices (like the middle ring).

 

Funny thing about a worn chain rings is that it may cause problems with shifting (like shifting from warn middle ring to small ring, where the barbs on the middle ring teeth kind of keeps the chain from shifting down)

 

Will be good if you post some picks.

[Martin PJ]

Hi Grumpy,

 

I agree with advice given. Check for bent chain, stiff chain link, bent teeth on front chainring, bent teeth on cassette. Failing that, put new cassette and chain. My son's old bike had chain slip no matter what, ended up replacing the drivetrain and couldn't really see any problems with any specific component.

 

Cheers.

[Cassie]

Hi all...I agree with what is suggested here...BUT the OP said "new chain"...so in theory...the issue should not be with the chain??

 

Only solution will be to replace the parts (i.e. casette / cahinring) that is still needed to complete a new drivetrain.

 

PS: i just had to do the exact same replacement due to exact same symptom...

[droo]

If you just replaced the chain and not the cassette or rings, then there's your issue... there's only a certain amount a chain can wear before it takes the rest of the system down with it.

 

Start by replacing the middle ring, since that's where you think the issue is - if that doesn't work, then the cassette's your issue.

[clyde79]

Please help. The chain on my MTB seems to jump forward every now and then probably a link every full turn when it is on the middle chain ring.

Could this be due to the chain ring being more worn than the other two as I use it the most? The chain is new and the same length as the one I removed. This issue only started after the Berg and Bush and no matter how much tweaking I do I can't get the problem sorted.

 

The problem is most likely the ring, see the problem I was having:

http://www.thehubsa....nd-jumping-off/

[Gate closer]

Okay time to own up to being blind. While working through the suggested solutions out the corner of my eye I noticed that the middle chain ring was slightly bent and the chain was running on top of the teeth, only about three teeth bent. Thanks for all the good advice I did learn from it. First thing I am doing is fitting a decent light into my bike room so I can see what's going on