Grindy / rattly noise from front cogs.

[pepecat]

Hello

Occasionally i had a grindy type noise coming from the front cogs / chain mech of my bike - now it seems to be permanent. Looking at it whilst riding (on a quiet road!) it seems that the plastic guard outside of the three front cogs is not running straight (as in, there's a wobble of some sorts going on). It looks like what happens is that when the front cogs rotate round and get to the bit where they wobble, they're rubbing on the chain mech...or possibly the chain is.

Is this something i can fix myself, or does it need to be done by pros? (and if i can fix it, how??)

 

[Gerry Attrick]

It may only require the front mech to be re-adjusted, but from what you say, it may be that the chain guard or even the chain ring is bent.

Good instructions here for adjustment, but if the chain wheel is not running true then that won't help.

Depending on the chainset, it could possibly be trued, but unless you are mechanically confident, it may well be best left to a good lbs. It entails grasping the chainring with either a special tool or an adjustable spanner and bending in back to the correect shape. Don't do this just to see if that is the problem, or you could end up with a hefty replacement bill.

 

[twentysix by twentyfive]

+1

First try adjusting the front mech. If that works you are sorted. You can always adjust it back again if you need to. If the chainring is badly buckled you may very well need to replace it. Any idea why it may have gotten buckled? Did you hit a high kerb or something?
IIRC cheap chainrings do bend after a while anyway.