got around to changing my chain before the weekend, measured it, and it seemed to be on the limit, which seemed ok for 6 months riding. So popped on my new chain and headed off for 24-12. On the warmup lap worked out the chain was badly skipping on the mech… ok i thought, I must have measured it wrong, and the mech needs replacing too, not a big problem they were being sold at 24-12 with discount, so quick bit of fixing, and I have new mech to match new chain.

Doing the race on Saturday / sunday chain was skipping all the time, anytime I wasn't in the granny ring basiclally…

So is there anything else that I can adjust, or has the new chain managed to stretch in the 8 miles or so it was ridden on the old cassette? (seems unlikely to me, but what do i know….)

Help please…..

(new chain was Dura-ace-xtr put onto a new xt cassette)

Cassette ****

Yes old cassette was obviously, but the new one too?

stiff chain link?
Were you pedalling hard in the granny ring, when it wasn't skipping?
Not clear whether or not you've changed cassette and chainrings?

Put the bike in the stand and pedal it slowly watching the chain. You'll see if there's a stiff link straight away. Sounds possible though from the fact it's slipping in the higher gears.

If not then it sounds like you've changed everything apart from your chainrings??? (I take it when you say mech you mean cassette?) Are you sure it's not slipping on the chainrings?

You won't have fecked the chain riding it for 8 miles on the old cassette, done that plenty.

Had a look for stiff links can't see any.

Top gear in granny ring was fine, put putting power down in any middle ring gears, and I would be skipping. I did check and it is definitely skipping at the rear end not the front mech.

I didnt change the front chain rings, just the rear after it was skipping with the new chain. really dont want to have to replace both casette and chain again, but I have the fear that is what i will have to do… ;(

Did this on a mates recently. Was chain sucking a little on shifting – was stretched to between .75 and 1. So changed chain. Then jumping on front chainrings – changed big and middle and now fine. The rear cass was SLX but chainrings are cheapo deores. I always change chain – test then see if something jumps then change the part its jumping on so either chainrings or cassette or both if necc!. I always change the chain every 6 mo or on .75.

hmm, maybe it is the front chain ring then, i didn't think they could have worn so fast, and the teeth look ok, and no gaps showing under the chain. Ill see if I can find a ring that will fit off another nike.

thanks for the help guys

See if you can look down a bit when its jumping when you drive the crank arm down but soft chainrings can go from sound to jumping fairly fast if my mates deores (only 4 months old) are anything to go by 🙂

I have the same problem, my chains skips only on the 2nd chainring on the cassette, does that mean the cassette is bust?

Had same problem a while back. New chain and loads of phantom shifting/skipping under load, so new XT cassette but no improvement.

Strip down, clean and inspection of drive train revealed nothing obviously bent or damaged. Putting everything back no improvement so decided to redo the indexing setup which revealed the high stop (resting) was wrong. Sorting that out fixed the problem. With the middle ring you generally get the most adverse chainline so a new chain with less flex is going to exert more force.

Just consider that new isn't always perfect.New and matching shimano stuff took two days of crappy riding before they all ran and indexed smoothly for me.

does that mean the cassette is bust?

You can get replacement individual prockets for rear shimano cassettes but maybe you need to check your indexing is all OK first and chain stretch etc before buying stuff!

Beware of misleading symptoms though – clearly you are directed to the chain and cassette because that has just been changed, but check/clean/lube/and/or replace the gear cable and re-set indexing (double-check upper and lower screws) first. Check for stiff links. Check jockey wheel bearings. Plus are you certain its not the freewheel skipping?

Having said that, its probably the middle chainring. A regular Deore steel will last a lot better and doesn't cost much.

I had something similar after replacing a chain and it turned out to be the chain jumping on the cassette. The cassette didn't look worn but after I changed it the jumping had gone.

the exact same happened to me, it was the front chainring that needed replaced.

Presumably the new chain/cassette was well lubed? We went to Scotland last yr and one of our group had a new chain (and possibly cassette). The whole of the first day her chain kept jumping under moderate to hard efforts.
We stopped & applied loads of lube to the chain & it sorted it straight away.

Before changing things I would check the set-up of the rear mech. Could be that it isn't set quite right with the new chainring.

I went past someone on the first lap of the 24/12 up the road climb who's gears were clunking something awful. He was weaving all over the place to try & keep some momentum going…..wasn't you by any chance was it? I think it was a grey hardtail.

Stumpy, yes it is all well lubed, Im going to have another fiddle with it today although I am thinking that the culprit might just be my middle chainring.

That grey hardtail must have been somebody else, although I did have a few loud clunky moments on the first big hill, till I worked out to stay in the granny ring. I was on a Red Orange Five.