chain slippage

[BigonaBianchi]

the bike has been fitted with a new chain and cassette. The chain slips badly on the smaller front cog, but is ok on the larger cog. The derailer is lined up ok as far as I can tell and it shifts one cog at a time ok on the bike stand, but under pressure on a ride it slips badly.

Any thoughts?

I ride 80% of the time on the large front cog, the smaller one on hills, I'm a heavy rider and the front cogs are those that came with bike several year ago.

Im wondering if this is a front cog issue...but cant see any damage, or wear different to bigger one.

 

[summerdays]

Sounds like the sort of thing where they normally recommend replacing the rings. I'm about to change my chain and cassette, and I know my chain rings are worn ... and need to replace them - well at least the middle one, but I find it very complicated to work out which one I need ... (I've worked out I have 4 bolts and I want 36 teeth but not sure about the measurements and how the bottom bracket comes into it!). How many miles have you done on them and have you changed the chain and cassette before? (Somewhere I read you could get away with one chain of cassette sometimes but after that you probably need to replace the front set too).

 

[ColinJ]

It is new little ring time!

 

[slowmotion]

I have a similar problem to BoB, except that I have a triple. I ride for 95% of the time on the middle ring. A week ago I replaced the middle ring, chain and cassette. It slips when I'm riding on the middle ring. Does anybody have any suggestions? It's driving me bonkers.
Thanks.

 

[BigonaBianchi]

in my case removing a chain link cured it