Front Derailer Rubbing slightly

keith_d99

Hi all,

Getting some rub on the front derailer. Have used the barrel adjuster, but still getting some slight rub. I have noticed a very slight wobble on the front cogs - not much though. Could this be a factor?

Thanks,
Keith.

kenmc

which gears are you in on the back when it rubs?
you may need to adjust your limit screws on the derailleur if you're not cross chaining. Sheldon will tell you how to do that too.

keith_d99

I get the rub on both the high and low gears at the back - no rub then in the middle gears - the rub seems to happen most in the middle cog at the front.

bcmf

Seems to be a front mech day.
make sure the chainring bolts are all thight. If they are then grab your crank and see if there is any play at all.If there is then you may need a new BB and no amount of adjusting will stop the rubbing as the front rings are wobbling.

kona

keith_d99 wrote: »

I get the rub on both the high and low gears at the back - no rub then in the middle gears - the rub seems to happen most in the middle cog at the front.

what bike do you have?

keith_d99

I'll try that - Presuming they are the 4 or 5 bolts adjusted using an allen key???
Well bike is only 3 months old - so all should be covered by warranty. Should I just accept it if there is a little rub on the highest or lowest?

bcmf wrote: »

Seems to be a front mech day.
make sure the chainring bolts are all thight. If they are then grab your crank and see if there is any play at all.If there is then you may need a new BB and no amount of adjusting will stop the rubbing as the front rings are wobbling.

keith_d99

It's a Trek 4300 disc

kona wrote: »

what bike do you have?

kona

keith_d99 wrote: »

I'll try that - Presuming they are the 4 or 5 bolts adjusted using an allen key???
Well bike is only 3 months old - so all should be covered by warranty. Should I just accept it if there is a little rub on the highest or lowest?

oh just saw its a trek? Suntour cranks by any chance?

kona

just googled i there, indeed suntour cranks......

I dont know what it is about suntour but loads of their cranks warp or uckle very very easy.

Depending on how old the bike is, Id be suprised if it was covered under warranty.

keith_d99

All that was needed was proper adjustment.
I had a go myself - and had it very nearly right, but had to bring back to shop for more accurate adjustment. Yer man tore into it, was trying to catch exactly what he was doing. Mind you it still took him about 20 mins.

Either I'm useless or there is a bit of an art to getting things spot on? Maybe a bit of both

kona

keith_d99 wrote: »

All that was needed was proper adjustment.
I had a go myself - and had it very nearly right, but had to bring back to shop for more accurate adjustment. Yer man tore into it, was trying to catch exactly what he was doing. Mind you it still took him about 20 mins.

Either I'm useless or there is a bit of an art to getting things spot on? Maybe a bit of both

Patience, tools and knowledge. Nothing is a bigger pain in the hole then adjusting gears on a unside down bike...stnd is soo much easier! once you know what you are doing a bit of patience.

Still shouldnt take 0mins to adjut a front mech, unless its a disaster.

keith_d99

No stand I'm afraid - and maybe patience a bit lacking - bike is only a couple of months old, so no charge from the bike shop

Can't say it's a job I like doing - hopefully the adjusters is all I will need to use for the forseeable future