Hi all. PLEASE can I have some suggestions with a chain slip problem. I’ve just built a bike and am running 9sp rear Shimano cassette (nearly new), new Sram 9sp chain, and a new 36T Ethirteen front single chainring. Rear mech ios Sram X9 (used)

On the smaller cogs (higher gears) from 5 upwards the chain is slipping under hard pressure pedalling, ie when there is a lot of torque going through the chain. This does not happen in low gears. I am 90% sure the slip is on the front ring. It feels like the chainring is not gripping the chain and slipping round a link.

Things i’ve tried –
1) The chain is aligned ok to the front cog – ie it seems to sit on it fine.
2) There is enough tension in the chain (3 links removed from new chain
3) I’ve increased the tension in the rear mech.
4) It’s not rubbing on the chain guide
5) The BB spacer is on the non drive side
6) The chainring is on the inside (frame side) of the crank.
7) I’ve tried moving the chainring to the outside of the spider and made no difference.
8) All the links in the chain move freely.
9) The mech hanger is stright.
10) The rear mech jockey wheels are moving freely.
11) The gears are set up fine.
12) The chainring is straight, all the teeth are fine and there are no imperfections.

I’m at a total loss. I seem to have tried every suggestion on Google!

Any other ideas?

Worn cassette and chain rings?

How nearly new is your cassette?

You need a new cassette.

Is the mech able to pivot forwards and backwards correctly or is that joint a bit seized?

Well, the bike I bought used so i couldnt’t say 100% but the rear cassette looks in good condition to my reasonably knowledgable eyes.

I’ll bow to your better knowledge but I thought as the slip ‘feels’ as if it’s at the front it wasnt a problem with the cassette….

The mech is fine and moved backwards and forward taking the slack no probs.

hmmm shimano and sram dont go well together… shimano is a different ratio to sram…. use all shimano parts or all sram parts…never mix the two together…. thats what i was told anyway.. its prob your sram chain

SRAM chains are fine with Shimano gears, so that’s probably not the issue. (not sure what ratios have to do with chains)

My money is on the cassette being more worn than the OP thinks – especially as It’s ok in some gears and not others.

it is incredible how new looking a trashed cassette can be. Spent a few minutes the other day cleaning the cassette on my road bike, looks like new but has done 7000miles.

Another one for new cassette. Had this with a part worn cassette and new chain. Then wears cassette really quickly. Sharkfin gears anyone.

Elaine that’s not true. Only rear mechs and rear shifters are incompatible. Rest is fine

Almost certainly the cassette – there’s quite a difference between looking ok and being ok.

GB

Now it’s been pointed out I guess it must be the rear cassette. It’s the only unknown factor as everything else is new and I’m fairly reasonable at setting things up.

In fairness I’ve not given the cassette a thorough examination for tooth wear. It’s cleaned up very well, but as mrmo says, clean doesn’t mean not trashed.

I guess it’s slipping on the rear but that is jerking the whole chain and i’m feeling it through the cranks, so i’m mistaking it for movement from the chainring.

Cheers guys, I’ll order one tonight and I’ll update the post to let you know if it worked. If it doesn’t work i’m going to go mad!!!!

I’m going for the freehub slipping. Does it only happen in cold weather?

Worn cassette.

Worn cassette.

Are you certain the bb spacer is meant to be non-drive side?

Try a new cassette, dont chuck the old one just in case it isn’t that and it’s fine.

Then take a look at your freehub.

Recently replaced a cassette due to slipping and it turned out to be the freehub

I have a new 9 speed cassette you can borrow to see if it works. (Actually used a couple times)

I will need it back after.

I too was going to suggest freehub slipping, feels like chain slip too particularly common sub zero temps. Having just typed that I put on brand new chain at the weekend and spent half the ride slipping on what looked like an okay cassette-new cassette on order when I worked out how many chains I had worn to .75 stretch on it….

I had this a while ago and it turned out to be a bent derailleur hanger!

If the cassette swap does not fix it, that is what I would look at after.

HTH
Al.

I once had a cassette where a nine speed cog & spacer was in amongst the eight speed ones. That took some finding, and all the cogs above it jumped…

Sounds horribly familiar to when I cobbled a build together. After much pulling out of hair I tried – just on the off chance – a cheap and new Deore chainring. Problem solved. LBS were a bit baffled too

On close inspection the cassette does actually look pretty worn. I missed it on the rebuild. CRC here I come!

I hope it not the freehub body. The amount I’ve spent fixing up this used bike I should have just bought new!

Last question!

Is XT worth the extra £15 over SLX

Also 11-32 is what I have currently. Am I missing a trick with 11-34? To be honest I normally push up big hills!

Slx works exactly the same as an xt cassette and will be every bit as durable. Even better – get a sram cassette. How old is your chain?

Don’t worry about 34t unless you see one cheaper than the equiv 32.

ok… is chain a bit slack? I’m sure I took more than 3 links out for my 2×9 set up?

Check jockey wheels and deraileur postition. I’m sure you’ve checked the mech is in the right place, but mine started to slip and it turned out the mounting bolt was loose and the whole mech was pulled forward! Slightly stiff jockey wheels could “bunch up” the chain then suddenly give causing a lurch, as could a stiff link.

Check front mech? Sometimes my cx bike slips and it is the chain derailling slightly as the front mech isn’t quite perfect and the chain is grubby with commuter crap. Check chain line and BB spacers to ensure its not at a funny angle which is upsetting it. Failing that and all the above hints, through it in a canal and scream. It wont help, but it’ll make you feel better (until you get cold and wet retrieving it)

+14 for cassette

+15 for the cassette 🙂 Had to replace a 200 mile old XTR cassette once because it had worn massively, so nearly new means nowt. Skipping at the front really rarely (but not never) happens due to the higher tooth count engaged with the chain.

hmmm shimano and sram dont go well together… shimano is a different ratio to sram…. use all shimano parts or all sram parts…never mix the two together…. thats what i was told anyway.. its prob your sram chain

Bobbins 🙂 Mix anything but the Shifters/Mechs

Don’t worry about 34t unless you see one cheaper than the equiv 32.

Far too personal to generalise depends on location, cadence, legs and what you want to do.

SRAM PG990 cassettes were going cheap round the place. Very nice. The type you need depends on your hub, alloy freehub on a hope is better with some.

+1 for check chain length

Also 11-32 is what I have currently. Am I missing a trick with 11-34? To be honest I normally push up big hills!

Bigger spread, depends on how your legs are. I’d take the 11-34 with a bigger ring up front rather than loosing top end bu getting a 32.

SRAM rear mechs like to be run with the angle of dangle srcrew wound out, so the jockey is close o the cassette.

The previous chain probably was run for too long – it was cheap and stretched quickly so the cassette might not be that old.

Try a new cassette to see if the slip stops.

If it does then buy another two new chains and run these three chains on a rotation basis so each get an even amount of wear.

Once all the chains have stretched a bit (get a park checker), change the cassette back to the other one, and continue using these three chains for a while longer.

When the chains are knackered, replace with another three new chains and repeat the procedure, switching back to the other cassette if you can – if that one slips then get a new cassette, and rotate across all three cassettes if you can.

That way you will get a good usage of the current cassette and might be able to keep it going for a long time.

TurnerGuy – Member
The previous chain probably was run for too long – it was cheap and stretched quickly so the cassette might not be that old.

Try a new cassette to see if the slip stops.

If it does then buy another two new chains and run these three chains on a rotation basis so each get an even amount of wear.

Once all the chains have stretched a bit (get a park checker), change the cassette back to the other one, and continue using these three chains for a while longer.

When the chains are knackered, replace with another three new chains and repeat the procedure, switching back to the other cassette if you can – if that one slips then get a new cassette, and rotate across all three cassettes if you can.

That way you will get a good usage of the current cassette and might be able to keep it going for a long time.

POSTED 53 MINUTES AGO # REPORT-POST

Why bother with this faff?

Why bother with this faff?

so he gets some usage out of this cassette which appears knackered.

the three chains on rotation will wear the three chains evenly and extend the time before he changes to the other cassette, when he can keep using them.

Even if he doesn’t keep the other cassette the three chain plan is a good way to maximise chain/cassette life, unless you always change your chain before it gets to 1.0 on the park checker, and even then this is often too late it seems, with 9 and 10 speed cassettes (used to always work with 8 speed XTs for me).

Feel free to make a better suggestion – i.e actually contribute to this thread…

10 points for those of you that suggested changing the cassette. A new set of cogs has fixed it completely. Plus given me an excuse to service the hub…

Thanks for all the advice.

Apologies for being unusually curmudgeonly this afternoon, blame it on the cold I seem to be coming down with, but anyway:

1) Thread title of “Chain Slip – tried everything” was a bit misleading when you hadn’t tried what, and the posts of other members seems to bear me out on this, would be the default first thing to try in this situation (new cassette). Thread should have been “Chain slip – tried everything apart from the bleeding obvious”.

2) Couple of references to chains “stretching”. This is wrong. They don’t stretch, they wear. The reason your wear gauge slips into the gaps is because of wear, not stretch. There’s a reason why they’re called chain wear gauges.

[/grumpygit]

Half link chains can stretch

EDIT: But I’ve got to agree! Tried everything but the most obvious things to try 😉

EDIT 2: Title entices the curious STWer in though.

It’s easy in hindsight eh? You’re right though it was obvious when it was pointed out. I made an assumption about the condtion of the cassette based on what I was told by seller and how shiny it was!

In the future I’ll consider my thread titles more.