Chain rubbing against frame

[pauloc]

Hi Guys,

 

I've noticed that my chain rubs up against my bikes frame by the bottom bracket when I'm in the small chainring up front (irrespective of the gear selected at the back). It's just touching so it's rubbing very lightly, not drastically.

 

I'm currently running a Truvativ Noir Crank on my Zula with an XT drive train.

 

Is this normal? Can I add a spacer to increase the gap?

 

Cheers,

Paulo

Edited March 15, 2012 by pauloc

[amasendeinja]

If that's a Zula as per your avatar then it has a 73mm bb shell so should not require any spacers installed on the bb cups. I would install a 2mm spacer on the drive side bb cup and see if that works. It may mess with your chainline, but you should notice this immediately.

 

The above suggestion made on the premise that there is nothing blatantly obvious that is causing your chain to rub on you frame. A trip your you LBS (if they're switched on) may be your best bet.

[covie]

Make sure your front derailure is properly aligned.

[pauloc]

If that's a Zula as per your avatar then it has a 73mm bb shell so should not require any spacers installed on the bb cups. I would install a 2mm spacer on the drive side bb cup and see if that works. It may mess with your chainline, but you should notice this immediately.

 

The above suggestion made on the premise that there is nothing blatantly obvious that is causing your chain to rub on you frame. A trip your you LBS (if they're switched on) may be your best bet.

Thanks man - I'm going to take it in to the LBS on the weekend and see what they think. The consensus so far seems to be that I need a spacer to move the chainline out a bit away from the frame.

[pauloc]

Make sure your front derailure is properly aligned.

That's how I actually noticed this. I was re-aligning the derailleur and I noticed it rubbing when checking the low limit screw. I could maybe push the derailleur outwards, but then the chain will be rubbing against the inner derailleur plate instead of the frame?

[covie]

That's how I actually noticed this. I was re-aligning the derailleur and I noticed it rubbing when checking the low limit screw. I could maybe push the derailleur outwards, but then the chain will be rubbing against the inner derailleur plate instead of the frame?

Thats why the plate is there. And generally you dont use the gears too much where it rubs against the derailure.