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Need Help on Adjusting FD on a Triple(4 posts)

Need Help on Adjusting FD on a Tripleastrobiker
Apr 14, 2003 4:33 PM
Can anybody give me some advice on adjusting my Shimano 105 front derailleur? My problem is that the chain drags the outside of the cage in the middle ring when on the small cogs in the back. If I tweak the barrel adjuster to make it quiet (move outward), then it won't downshift from the big ring, and looks too far out when on the big ring. It looks right on the big ring/small cog and on the small ring/big cog combinations. Just can't get rid of the chain drag at middle ring/small cog. Chain is brand new, as is the RD.

Thanks for any advice!
Need Help on Adjusting FD on a Triple.....heredavet
Apr 14, 2003 4:40 PM
from the Park Tool School, it's the definitive answer. Do the adjustments, in order, and your derailluer will work perfectly.
Double check your adjustments, and avoid cross-chain!BergMann
Apr 14, 2003 5:01 PM
Make sure the cage is parallel with the rings, and 1-2mm above the teeth of the big ring. If it still makes noise, chain line may be to blame.

Remember, just because your 30-something tooth ring is in the middle doesn't make it a good idea to ride cross-chain (the spacing between the rings is just as big as with a double, hence you're stressing the chain just as much as if you were fully cross-chained on a double)!

Third cog or so from the top and big ring should give you a comparable gear-ratio.
Follow this procedure exactly.Spoke Wrench
Apr 14, 2003 8:10 PM
STI triples can be a pain to set up. Usually, once you get out of sync, you start making adjustments that chase the problem to a different area. That's what you described now. The solution is to move everything back to the default setting and start over.

1. Disconnect the shift cable. (Important)
2. Adjust the derailleur on the seat tube so that the outer cage is parallel to the big chain ring and misses the top of the big chain ring by about 2mm when you push the cage outward with your finger.
3. Set the low gear limit screw so that the inner cage misses the chain on the granny gear by about 2mm.
4. Now pull the cable taut with your needlenose pliers and attach it to it's anchor screw. Be sure that you go the correct way around the anchor screw.
5. Try shifting up and down the gears with the rear derailleur in a variety of positions.
6. Set the high gear limit screw so that the outer cage misses the chain on the big ring by about 2mm.