Direct Mount FD

[MartinO]

I have recently started having problems with my direct mount FD on my GF Superfly 100. It is impossible to shift into granny gear from the middle chainring. There is no real problem when double shifting from the 42t ring into granny. I have checked the L and H screws and they are not preventing the change.. this happened after a service and my thoughts are that perhaps the FD needs to be dropped down a fraction to allow the cage to get a bit more bite on the chain... any ideas?

[Johan Bornman]

There are only three things that can prevent, or make that change difficult.

 

1) The limit screws.

2) The cable tension.

3) The derailler bottoms out against itself or against the frame.

 

The first two, it seems, you'll be able to cope with.

 

The latter is 9/10 times the result of faulty crank instlallation. Usually the BB cup spacers are now all on the left rather than on the right etc.

 

For a 73mm bottom bracket, you should have one spacer on the left.

For a 68mm bottom bracket, you should have two spacers on the righ and one on the left.

 

These spacers have the effect of moving the crank left or right and you'll be able to visualise what this will do if the FD's swing range is already limited.

[MartinO]

The Superfly has a BB95 press fit bearings... and the change was perfect before the bike went in for service. I also know the guys pulled the FD off for cleaning. Will check spacers tho.

[Johan Bornman]

The Superfly has a BB95 press fit bearings... and the change was perfect before the bike went in for service. I also know the guys pulled the FD off for cleaning. Will check spacers tho.

I see. Still, only those three things can prevent the change. Isolate it. Remove the chain and cable and see if the FD can physically move to where it should go. Find what prevents it. I'd like to know how you solved this one.

[MartinO]

Tx Johan,

cable tension and frame bottom out - nope...

Removed the FD and noticed when the screw is loosened, the FD tends to push out... cleaned the surfaces (a little dirty) and tightened up... works a treat now. Don't think it was dirt related, just not tightened up properly. Problem solved.