Found the noise...

[ScotiaLass]

I've had a noise, like something rubbing against the chain, on my MTB for the last couple of rides.

The bike is currently on the workstand and I've discovered that the metal guide where the chain runs through before it goes ont the chain (deraillieur guide?) is *just* touching the outside (knobbly bits) of my tyre. but doesn't always (if that makes sense!)

The rear wheel is seated correctly and it only happens in the lowest 3 gears.
Firstly, could it have moved and secondly, how do I adjust it?
I took a pic but I'm outside on my tablet and the pic is on my phone lol
Help!

 

[ScotiaLass]

I've come indoors to post the pic...not very clear but the inside edge of the 'guide' is just touching the knobbly bits on the outside of the tyre

 

[MontyVeda]

it could have been knocked out of alignment a tad, so the clamp around the seat tube needs loosening and the dérailleur twisting* a tad... but try not to alter it's height on the seat tube... or it could be a case of adjusting the distance the derailleur swings, which is done by turning one of those two screws (just by the seat tube in your pic). I'd be tempted to try this first.

*the dérailleur should be in line with the chain rings.

 

[Levo-Lon]

As above.
do this in the 22 cog..so the cable is slack.

the chain guide needs to be in line with the cogs..

see how that goes ..

 

[ScotiaLass]

Sorted!
I used the screw...only needed a tiny adjustment...noise gone and gears playing nice

 

[paul-kent]

Sometimes a little screw is all it takes

 

[ScotiaLass]

Sometimes a little screw is all it takes

Wey hey!