Adjusting front derailleur
 

Hi,

I am currently setting up my new shifters and there is a minor problem in that I don't have a barrel adjuster for the front derailleur but I think I can get around that!

My problem is that when on the big ring and in the highest 3/4 gears on the rear the chain rubs the outer side of the cage slightly.

The derailleur was previously correctly adjusted so I guess the limits are ok - my thinking is that the campy shifter pulls just slightly too little cable to get the derailleur in the correct position. Is this the case or is there something I can do to set it up properly?

Could this be a case of needing to take out more cable slack before clamping the cable? I thought this, but in the smallest ring and lowest gear the chain is very close to the inner side of the cage and any closer I think it would rub.

Thanks

Daven

Edit: By taking out more slack I think I may have cured the problem - was in the highest gear and biggest ring and there was little to no rub. I may have lost the lowest gear (will find out when I set up the rear derailleur) but I don't mind as I never use that! Any other things I can check/do?

Thanks

By doing without a cable adjuster you're doing it the hard way. It's possible, so in the lowest ring position with the chain on the largest sprocket at rear and the cable slack, adjust the "L" screw so that the chain just misses the inside plate on the FD cage. Now take up the slack on the cable so that it is just taut and no more. Now try the change.
If however this is a Road triple we are talking about then a cable-adjuster will be needed to get the fine adjustment necessary for this to work properly.

Like onbike says, you should be able to eliminate rub by tightening cable and adjusting limitscrew. However, a longer term solution would be to cut one of these into your cable housing:

http://www.biketiresdirect.com/pjbba...djuster/pp.htm

If you have Campy ergo levers, they have enough cable pull to handle any FD. There should be up 12 clicks. No more than 4 are needed for a double FD and 7 for a triple.

Never assume that the limit screws are set correctly. Take the cable loose and start over, with shifter set to the start position. Push the thumb all the way down to be sure that no more clicks remain. Set the low limit screw so there is no chain rub in the little ring and largest cog. Intentionally screw the limit screw in (CW) by 1/2 turn, then attach the shift cable, pulling it tight with pliers. After the cable is attached, loosen the low limit screw so it's back to the original postion. This put more tension on the cable. Try shift to the big ring (or middle if you have a triple). This should be done with one sweep of the finger lever, taking 3-4 clicks for a double or 5 clicks with a triple. If the FD doesn't make the shift and hits the limit screw, then back it out enough to allow the shift to execute (double crank only). If there is not enough tension on the cable, go back to the beginning point, detach the cable and try 3/4 turn rather than 1/2 turn, to pretension the cable.

Thanks guys. I will try as suggested. At the moment it goes into the middle ring with 1 sweep of the lever, and then into the big ring with the final sweep. Will report back!

Here's the daily Copy & Paste:
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Take the cable off the FD. Now install it from scratch as per Park Tool Repair:

http://www.parktool.com/repair/readhowto.asp?id=75

And BicycleTutor:

http://bicycletutor.com/adjust-front-derailer/

When you have it properly trimmed and are ready for the cable - a new one wouldn't hurt - you want to pull the cable taut - not too tight, taut. Then apply 48 to 60 inch-pounds to the pinch-bolt. Then put it through it's paces.

It's always easier and faster to install a FD from square-one, than it is to make adjustments with it already attached. This tends to fix one thing - while throwing another out of kilter. Start fresh. You'll get it.

Adding an inline barrel-adjuster can solve many problems with the cable coming loose - or being too tight.

Barrel Adjusters:

http://www.biketoolsetc.com/index.cg...rrel-Adjusters

Thanks, I managed to get it working. I put a bit more tension in the cable and I think when I shifted I didn't push the shifter all the way to the end of it's travel on the final click. When I push it all the way the cage moves just far enough to stop the chain rub - it also works for the small ring, low gear combination too :)

I like these barrel adjusters...then you don't have to cut the cable.
http://www.ebikestop.com/jagwire_roc...ack-BR4058.php