Thanks for your help thus far Jmo � I know the cush is OK as I've just replaced that with a new one. I'll check the wheel balance tomorrow � didn't find any loose bolts during a once-over today so I guess the process of elimination is well under way. I'll check the chain tomorrow too.

Need to get it fixed as I'm doing a 2,500 mile trip at the end of June and there will be quite a lot of road work � I'll need to service the bike before I leave, so I may belt-n-braces the whole deal and replace the chain and sprockets ahead of the trip too. Might need another new rear tyre by June too.