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STI w/ top pull mtb mech.(4 posts)

STI w/ top pull mtb mech.TWD
Dec 2, 2002 11:06 PM
There have been a whole lot of posts lately regarding whether or not you can run STI levers with a top pull mtn derailluer.

I was one of the ones asking, and have since found a setup that works. My bike came spec'd with an LX top mount der. and 36/48 double crank and 105 STI levers.

It shifted fine using the double setup, but I ended up swapping the cranks out for a Raceface crank with 24/34/46 rings. I ran it as a double this fall for racing, but after my last race I decided to give the triple setup a try since I do alot of long, steep, and muddy singletrack climbs in the winter.

I put the granny ring on and adjusted the derailluer limits and cable tension. I couldn't get it to work. The shifter just didn't have enough pull to make the full range.

Then a thought occurred to me. I had read somewhere (Sheldon Brown maybe?) that some older derailluers had a clamp mechanism that allowed you to either clamp the cable on the inside or outside of the clamp bolt that in effect allowed you to change the effective leverage on the derailluer.

The LX derailluer doesn't have that old style clamp mechanism, but I was able to get enough of the cable underneath the washer to clamp it inside (closer to the frame) of the pinch bolt. Guess what, it worked. The darn thing shifts perfectly in all gears(better than my mountian bike does).

Go figure. I may take a dremmel or file to the derailluer to cut a slight groove so that the cable sits in there a little better on that inside position, but so far it's fine.

Can't make any claims as to whether is would work with a road triple crank, but works good on the mountain crank.

I'm not advocating that you go out and buy the parts to try this setup, but if you've got the stuff in the parts bin and want to give it a try, it's worth a shot.

Ok, that's my near worthless experiment for today.
re: STI w/ top pull mtb mech.OffRoadTourer
Dec 3, 2002 6:13 AM
Good one! I'll try your theory out shortly as I was one of the ppl having trouble. Hope it works for me. Will report back.
re: STI w/ top pull mtb mech.atpjunkie
Dec 3, 2002 12:32 PM
I've been running XTR's with road levers (2 bikes) one with a triple and no problems
re: STI w/ top pull mtb mech.The Walrus
Dec 3, 2002 4:22 PM
No need to do anything as drastic as filing a groove in the derailleur--just route the cable along the inboard side of the bolt and wrap it around (underneath the washer) so that the end of the cable exits the clamp pointing upwards on the outboard side.