Chain not worn constantly slipping

[Fifelad]

The chain has plenty of life left in it, nowhere near 75% worn. But it’s skipping all over the place now. A worn cassette was my first thought, but I always changed the two together regardless. It’s not even a gradual slip in certain cogs, it’s literally impossible to ride not holding any gear now. It’s changing perfectly in the stand but the problems are under tension when riding. Only thing I can do is get a new cassette try it, see if it works if not then I’m stumped and it’s to the LBS.

 

[Punkawallah]

I’d be inclined to put on the old chain to see if that works. If so, you could be looking at a replacement chainset.

 

[Paulus]

Has the indexing gone out of kilter?
You don't say wether it is a mechanical or electronic shifting.
If you are going down the new cassette route I'd be tempted to put a new chain on it as well.

 

[Fifelad]

Mechanical; indexing is perfect when on the stand. Only problems when under tension. Could it be a free hub issue ?

 

[Shearwater Missile]

Two things spring to my mind. Depending where the chain is skipping. Is it skipping on the cassette ? If that is the case then perhaps it is a bent hanger. If it is skipping on the chainring then perhaps a worn chainring. Does it do it on both chainrings, assuming a two ring set up. Personally, I have only ever had chain slip on the cassette after replacing a chain on a worn chain and the second time was after the bike fell and bent the hanger. I had`nt realised until I got on the road and it was skipping in all gears, like yourself.

 

[Ming the Merciless]

What has changed? Presumably it did not go from perfect to shifting all over the place.

 

[Shortfall]

Mechanical; indexing is perfect when on the stand. Only problems when under tension. Could it be a free hub issue ?

I had this once after hauling my father hefty self up Park Rash on a 52/29 set up. It felt exactly like a skipping chain but on examination the the freehub wasn't up to the strain, even if me and the chainset were, and the pawls had slipped and taken big lumps out of the splines.

 

[Ian H]

Check for stiff links in the chain.

 

[cyberknight]

i always find you need to tweak it after setting it up on the stand and there is a good chance that under tension its a bit different .

 

[DRM]

Is the gear cable frayed where it goes into the short length of outer, just before the derailleur?

 

[Fifelad]

What has changed? Presumably it did not go from perfect to shifting all over the place.

Virtually yes. A couple of skips between middle sprockets then everything.

 

[MontyVeda]

If you've got an old/spare wheel you could try the cassette on that, it would at least tell if it's a freehub issue or not.

 

[Fifelad]

Is the gear cable frayed where it goes into the short length of outer, just before the derailleur?

No

 

[Fifelad]

Is the gear cable frayed where it goes into the short length of outer, just before the derailleur?

No

 

[Fifelad]

Check for stiff links in the chain.

No stiff links