Front Derailleur sending me mad !!!

flyer

I am trying to adjust my Front Derailleur but even when I follow detailed video instructions I still cant "fine tune" the chain so it doesn't touch the derailer.

It either slightly touches whilst on highest gear, ie smallest cog or if I adjust it then touches on the largest cog.

I cant get clearance at both ends

If I move it up to the second smallest cog its ok, is it normal for the chain to rub slightly

Any help appreciated


Flyer

Ben6899

In the big ring at the front: you will have some rub when in the 23,25,27 or whatever you have up there.

In the small ring at the front: you will have some rub when in the 11,12,13 or whatever you have down there.

Cross-chaining.

pilot_pete

My Campagnolo set up doesn't rub, and my sons Shimano setup doesn't rub, even if on 'big-big' or 'small-small'....

PP

topdude

It all depends on the front mech cage / flexibility of the chain / length of chain stays, every setup is different.
Some might achieve it but you may never get clearance at both ends on your particular setup

fludey

Both of mine rub both 105 and ultegra but the levers have a half way click that just shifts the mech slightly.
On another note I have often read you shouldn't run to that extreme of gearing as the chain is under a lot of stress at that angle I.e. Big cog front big cog rear or small cog front small cog rear shouldn't be ran.

No doubt someone will say that's rubbish thou

merak

Have you adjusted the limit screws?

flyer

Yes I have adjusted the limit screws.

In terms of chain being on put under too much tention!

The chain rubs on the derailer (Small chain ring) when on smallest and largest cog

When used on the large chain ring its fine

This is on Ultegra.

Flyer

fludey

If it's ultegra are you using the levers correctly as it gives 4 positions for the front gear?

You should be able to move it and get no rubbing at all but you do have to use the half way clicks?

When setting limit screws make sure you are fully shifted to lowest and upper most position on the lever.
When on the small ring up front big cog rear adjust screw so chain is just clear of front mech, once set make sure you set tension in the cable. Now drop chain to small cog rear small cog front still, it will rub but give the lever half a click and it should shift just clear.
Then full shift to big cog front small rear, make sure lever is all way over and then set limit screw so just clear of the chain.
Now shift on to big cog rear and front, give the lever half a click to change down on the front ring it should hold on big ring but clear chain.

Any joy??

flyer

Fludey

Thanks for that, I have done what you said and its better but still touching slightly.

I bought the bike last week from Leeds (about 40 miles from where I live) I will take it back in tomorrow and ask them to do it.

Thanks

Flyer

sloppyschleckonds

flyer wrote:

Fludey

Thanks for that, I have done what you said and its better but still touching slightly.

I bought the bike last week from Leeds (about 40 miles from where I live) I will take it back in tomorrow and ask them to do it.

Thanks

Flyer

Brilliant idea.

fludey

If they say you shouldn't be using that extreme of gear don't be surprised and not fobbing you off, shimanos own technical sheets say the same thing.

thecrofter

On my Shimano Sora triple I have been unable to find a window where I can use large chainring to large rear cassette or small chainring to small rear cassette. As has been said this is called cross-chaining and is not recommended by the manufacturers anyway. If you work out the actual ratios you have available you will find there is no need to crosschain, I generally use 4,5 and 6 switching between the large and middle chainring depending on terrain, anything else is for steep ups or downs. There is a relatively small window in the set up where I can have no rubbing on the front mech when in my topmost gear and no rubbing when on the lowest, for the odd occasion they are necessary, a bit of trial and error sorts it out.