Chain jumping on rear cassette

kenan

Building a bike up with parts from another frame. Have fitted a new chain with older cassette and chain set. When on the bike stand the gears work fine, however when under load the chain is jumping, feels like it is jumping forwarded not up/down a gear. I assume this means I need a new cassette, is this the case or is there another solution?

cooldad

Probably

The Rookie

Probably the cassette, can be the chain (measure it for stretch), but usually the cassette.

Simon

kenan

The Beginner wrote:

Probably the cassette, can be the chain (measure it for stretch), but usually the cassette.

Simon

But it's a new chain?

cooldad

Says he fitted a new chain, so somewhat unlikely to be that.

Rick_huggins

Slacken your rear shifter barrel adjuster

cooldad

Rick_huggins wrote:

Slacken your rear shifter barrel adjuster

That would help if it was not indexed properly - he says it is not jumping gears, but slipping under load.

Rick_huggins

Fair point