Mountainclimber

I have a minor problem, my chain is rubbing against the front derailer on my fsr xc. It seems to happen when the chain is on an angle in certain gear combinations and makes my bike soundlike a piece of @#$& and i dont like riding it like this. Should i adjust the derailer or is this not a good idea?

LowCel 

What gear combinations does it rub in? It is normal for it to rub sometimes.

Snuffleupagus

Having your chain at extreme angles is bad.

Many gears, especially on a 3 chain ring'ed MTB setup are redundant. You want as little angle as possible.

Flak

Sounds like cross chaining problem to me.

Dont run little up front, little rear, or big front, big rear combos etc.

OldNick

What "certain gear combinations" do you mean? I am assuming that the chain is rubbing on the side

closest to the frame (???). That is the commonest one. What bike do you ride? That can also make

a difference.

On most bikes you should not use the gear combos that place the chain on an extreme angle. So

small front / small back is a bad combo. You should change the front to the middle and lift up a

couple of cogs at the back to get the chain back in line, with roughly the same gearing.

In fact my bike (Giant Yukon) recommends that I don't use the smallest _two_ cogs on the rear with

the front in small, and the largest _two_ cogs on the rear in the largest front cog. So with the front in

1, I should not be in 7th or 8th on the back. I should go to 2 in front, and maybe 5th or 6th in the

back.

If however, the chain is rubbing in any rear gear with the front in the _middle_ ring, then it needs

adjusting for sure. Middle gear front should allow the full range of rear gears.

Whatever, you may need to adjust the front derailer. It ... _should_ .... not rub in any gear combo.

But if you cannot adjust it to stop rubbing at extreme chain angles, without causing gear change

problems, then use the front gears more, and make sure that changing gears is smooth.

Gear change problems will be most obvious when trying to move to a larger cog on the front, which is

when the derailer has to push the chain up to the cog. If the chain _is_ rubbing on the side closer to

the bike frame, then you need to adjust it so that it _just_ misses when you are in smallest front /

smallest rear. But as I say, if that causes gear change problems when going up in size, stop

crossing the chain rather than adjusting the setup.

OldNick

Just in case my message was not wordy enough I double-spaced it to make sure..<G>

Sorry bout that folks....

mtb-chop

+1 to all the cross-chaining advice above - in addition to rubbing, it will also wear your drivetrain faster.

Here's a link to Park Tool's page on front derailleur adjustment. It's very comprehensive and the procedure, when followed step-by-step, should result in a front derailleur that shifts perfectly.

Jason222

Just unclamp the derailleur and turn it, reclamp, and you're done. I have this problem all the time.

mtb-chop

F.D. adjustments are not so simple. When one thing is changed, it affects a whole host of others.

Jason222

Works fine when I do it.

cryptid01

Then why did you say you have the problem all the time? If it worked fine, it wouldn't keep recurring.

igno-mtb

i have the same trouble on my rochopper, the thing is that the chain rubs when the gears are like in the largest ring (3) and in the smallest cog (8) (24 speeds buddies), and adjusting the F D, doesnt help too much, i think there is not enough space to run the chain under this circumstances.

Jason222

I readjust it every 2 weeks or so. I hit the front derailleur a lot, so it comes out of alignment.

LowCel 

Wow, that is a lot of adjusting. I have only had to adjust mine once since I installed it about a year ago.

Snuffleupagus

Classic

mtb-chop

Exactly - beat me to it. As LowCel said, FDs should be a pretty much adjust it and forget it type of thing - if it's done right the first time. I use my FD a lot too and don't have to adjust it at all. Fire and forget.

Mountainclimber

It does it when i change gears to medium and large cogs on the front. Im not sure what gear i was in on the rear cogs.