Rear mech

[Trekdale]

Iv just been out biking with my mate who brought a Trek Terrago a little while ago and has restarted again, the top of his rear mech (the bit with the name righted on) was banging agains the chain stay, surely this cant be normal? Doest any one know how to stop this, is it just set up ronge or is it the rearmech for the bike, its a SHimano Deore one.
also while on the subject of rear mechs wahat is the bennifits of having a short cage rear mech... is it just so that your less likely to bash it agains rocks etc...

Thanks for any help

[fredmundo]

HeY trekdake, that is normal for a hardtail certainly, I'd be surprised if it didn't also happen on a full sus to some degree.
With regard to short medium and long cage mechs... It is to do with how much chain slack they can take up.
The general rule is
for a triple you need a long cage, mediumbfor a double and short for a single...
Is mainly clearance that they are used for, yes. Although I dare say you'll find the shorter one lighter.

[MTBLeague]

Look at this video it shows this quite well, yes you can put something there to stop the paint being chipped like a rubber patch or a bit of an old exploded tyre.

http://www.youtube.com/watch?v=AZQf1bduGYs

[Trekdale]

Thanks both =O) i shall install a bit of old innertube for him, to help stop the paint chipping and also to stop the realy irritating bangin noise!!!!