NCAA - DUAL CHAMPIONS!
Join Date: Mar 2000
Location: From Sarasota, FL sitting in front of a computer spewing random thoughts!
Bikes: Intense Uzzi SL, Masi Speciale, Trek 3700 Nashbar Single Speed, Old Cilo Road frame
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probably just needs adjusting.
Here's what you do.
1) First is make sure your derailleur is straight and set at the proper height. To do this, loosen the shift cable and loosen the seatube clamp (just enough to be able to move it, but not so loose it's just hangin). Use a penny and wedge it between the big chainring and the bottom of the outer plate of the derailleur. Then make sure the outer plate is perfectly parrallel to the big chainring. Then tighten the clamp bolt.
2)Next, adjust the limit stops. There are two small phillips head screws on your derailleur. One is for the inner limit set, and the other is for the outer limit. What you need to do is set the inner limit stop so when you shift into the small chainring(front) and large cassette cog(back), there is only about .5mm to 1mm clearance between the inside face of the derailleur cage and the chain. (looking straight down to it!) Just enough so it doesn't rub while pedaling.
3)then set your outter limit stop the same way. You will need to reattach the shifter cable to do this. Shift into the big chainring and smallest cassette cog. Turn the set screw out enough so you can make the chain shift OFF the outside of the chainring, replace the chain and tighten the set screw enough to keep that from happening again. Leave a bit more clearance (1mm to 2 mm) between the chain and outer plate of the derailleur. When stomping on the pedals, you can flex the bottom bracket enough to cause the chain to rub the derailleur, so give it just a little more space.
4) once you set your limit screws, shift back down to the smallest chainring and loosen the cable free from the derailleur. Turn your barrell adjuster at the shifter all the way IN, then back it out 3/4 to 1 full turn. Then attach cable to derailleur again, pulling the cable taut (sp?) to keep the slack out of it while tighening down the bolt.
5)Shift into the MIDDLE chainring and small cog. While pedaling, turn the barrel adjuster in or out to prevent the chain from rubbing. Then shift into the big cog and do the same. You'll have to go back and forth making smaller and smaller adjustment till you find a balance between the farthest in and farthest out adjustment.
6) This should now center your derailleur and should prevent any rubbing in the lower and upper gear combos.
7) Shift through the gears and verify. If something rubs, only make very small adjustments at a time.
***NOTE: if running 9 speed and you cross chain. i.e small chainring and small cog, or BIG - BIG, you WILL get some rubbing, this also puts a lot of stress on your chain and should be avoided anyways!
Hope that helps.
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