Chain Slip

daxplusplus

New Chain, new cassette, New rear derailleur cable and fairly new chain rings .. and I get chain slip when applying decent amount of power e.g. starting off or especially out of saddle on hills. It can happen in either chain ring but tends to be the smaller one as this is when I most likely out of the seat climbing a hill.

The chain is not too long. Gear changing is smooth, chain runs smooth. It feels like slip rather than hopping into another gear.

Any ideas? It's driving me up the wall.

smidsy

I had this and it turned out to be side plate damage (on newish chain).

Hard to spot and I actually replaced a freehub thinking it was that before finally finding the culprit.

leehill1507

I had a similar problem last week - it drove me mad trying to diagnose the problem, which like you was more pronounced on the smaller cogs.

I noticed that the link pin on my chain was slightly tight and not fully pushed in - when I replaced the pin, the problem with the chain slip vanished.

Not sure if this will work for you, but worth a try.

daxplusplus

Thanks for the input.

Hmmm.

Thing is that my old chain and cassette was doing it too but to a lesser extent. That's why I replaced them.

OK I'm going downstairs and having a look at them again to make sure that the rear derailleur is actually inline\working as well I think it is and see whether I spot any stiff\damaged links.

daxplusplus

Can't get it to slip while looking at in the garage just now but gear selection looks fine. Will try again later.

Will also try replacing rear wheel this evening to rule out the hub.

Bozman

I've had this issue in the last twelve months and a mate had exactly the same issue too. Two quarter turns of the cable adjuster on the rear mech cured it.
The gear change was as smooth as butter but when you got out of the saddle the chain would slip, someone recommended the fix on here and it worked a treat.

daxplusplus

Bozman wrote:

I've had this issue in the last twelve months and a mate had exactly the same issue too. Two quarter turns of the cable adjuster on the rear mech cured it.
The gear change was as smooth as butter but when you got out of the saddle the chain would slip, someone recommended the fix on here and it worked a treat.

Thanks - I'll try that on a 18% hill on my way home tonight. Fingers crossed.

daxplusplus

Couldn't get up the hill - had to walk due to chain slip. Aaaggghh!

But at least I discovered what was slipping .. it was the bloody chain rings. Which is weird .. cos it happens on both and they are fairly new. Could have sworn it was the cassette but no.

But at least now I know.

dee4life2005

I had this recently too. In my case it was a combination of a gunked up rear derailleur (ultegra) that meant the return spring couldn't take up the slack in the chain causing it to sag slightly ... and muddy water collecting in the internal cable routing guide tube at the bottom of the bottom bracket, causing the gear changes to not be as smooth and snappy as they should be.

I too had replaced the rear cassette, cable, chain ... and it was still doing it even after I swapped to a spare wheel that I had that I knew was good. This only left the derailleur or the cable outer run somewhere.

Might be worth checking that your rear derailleur isn't just needing cleaned, mine clogged with crap around where the jockey wheel cage attaches to it (don't remove the cage though) you couldn't see the dirt though as it had worked its way inside ... just needed a good squirting with GT85 and manipulation by hand in my case (for about 40 minutes in my case).

islwyn

Currently suffering with this EXACT same problem, new casette & chain and experiencing slipping in small ring, again chain isn't too long or short.

I'll check derailur gunk (even though it looks fine!), what made you workout it was the chainring?

daxplusplus

The main problem to understanding where the slip was occurring was that it is difficult to reproduce.

So when it did start happening on a hill, I stopped, got off and repeatedly tried to push the pedals hard enough so that slip happened. I just kept trying.

For me it seemed the easiest way to reproduce the slip was with the pedal at about 5 o'clock and push down hard.

dee4life2005

After cleaning mine, and removing / cleaning / re-greasing / re-tensioning the two hidden springs (not the visible one in the parallelogram) I was still having some small shifting issues, and the odd intermittent slip / skip of the chain. It didn't feel like it was shifting to a different gear.
I noticed that my jockey wheels were a bit pointy, and the derailleur springs didn't feel as springy as they should. Perhaps a little drastic, but I purchased a new rear derailleur to try that. It instantly cured my issue with both the shifting and the occasional slip. So in my case it was something to do with the derailleur ... I now just have to find out what.

islwyn

So I've fixed mine and thought I'd post fix up for anyone else who searches and finds this thread.

I clean my bike every week and like to think I'm up to scratch with maintenance, my current chainrings and double a few thousand K's so there was the chance of them being worn, as I was slipping mainly in the small chainring I bought a replacement, when I removed the chainset I the potential problem became visible, even though the chainring's teeth were in great condition, there was thick gunk built up all the way around the chainring that was hidden to view whilst on bike, after scrapping it all off - the new chain was sitting on it perfectly and is no longer slipping! That's £19.99 I'll get back on the replacement part.

Damn hidden dirt.

rolf_f

Islwyn wrote:

I clean my bike every week and like to think I'm up to scratch with maintenance, my current chainrings and double a few thousand K's so there was the chance of them being worn, as I was slipping mainly in the small chainring I bought a replacement, when I removed the chainset I the potential problem became visible, even though the chainring's teeth were in great condition, there was thick gunk built up all the way around the chainring that was hidden to view whilst on bike, after scrapping it all off - the new chain was sitting on it perfectly and is no longer slipping! Damn hidden dirt.

What bike do you have that you can't see the small chainring teeth?! The only ones I can't easily see are the ones behind the big ring spider. Otherwise there is nothing hidden about any of the teeth. I think you need to clean your whole bike rather than just the bits that show up in photos!

islwyn

Rolf F wrote:

I think you need to clean your whole bike rather than just the bits that show up in photos!

:oops:
Guilty.