Brand new bike front mech issue..

rhysyd

Hi

Brand new road bike, done couple 100 miles on it anyway, after a while, whilst in the big ring and the smallest cogs at the back the chain was rubbing on the front mech. So couple of twists of the barrel adjuster and everything seems fine noise has gone. But now the chain rubs on the front mech whilst in the small ring at and large cogs at the back?

I try to loosen the cable tension a tad so the mech comes away and leaves a mm or so, so the chain isnt touching, but then then it wont shift into the big ring. The only way i can shift into the big ring is by tightening the cable tension but then this causes the front mech the rub on the chain when in the largest cogs at the back and small chainring? Any ideas? H/L screws seem to be fine.
Thanks

fudgey

A good guide for setting up front mechs:

http://www.parktool.com/blog/repair-hel ... adjustment

sungod

start from scratch with the set-up - including height/alignment - as from your description something is wrong, might even be a bent cage

plodder73

Sounds simple to me, the only thing stopping the chain coming off the small chainring completely is the low stop screw. So if the font mech isn't coming inwards enough just let off the low stop screw a turn.