OD, any chance you are about pre ride tonight and that I might be able to swing by and borrow some garage space for a few minutes? My new chain is slipping (on my new cassette) but only when I am out of the saddle. Having looked at a few opinions one is that shortening the chain might be a solution and although I am not convinced I have a spare one so am willing to try to take a link out.
I have the tools but don't fancy making a roadside repair in case I drop something that is needed!