High Gears slipping under load

tallsam [quote]hippy Derr hanger been bent at some point after it was working well (installation of new stuff?)
It's usually a chain/cassette incompatibility as others have said though.. http://www.sheldonbrown.com/derailer-adjustment.html#autoshift

As far as I know nothing has been bashed or bent. The installation was fairly hazard free.
If it is infact a chain/cassette incompatability then its kinda the bike shops fault as I just asked for one and pointed to the bike. They checked it. Thing is they didn't fit it too so I've kinda got no comeback.

Oh well.[/quote]

Looking at that article its more than likely that I just need a new rear cassette.

I have no idea why I didn't just read Park and Sheldon religiously before I posted this problem.

Shouldn't be too expensive although my LBS will have to fit it as I don't have the tools.