Mountain Bike Reviews Forum banner
1 - 3 of 3 Posts

·
Registered
Joined
·
53 Posts
Discussion Starter · #1 ·
Hello everyone! I'm new to the forum and in need of some help. The cables on my newly built flux have stretched and recently required adjustment. I have the Shimano XT Dual Control Levers (Rapid Rise, I believe) if that matters. I started experiencing chain rub in the smallest to third cog in the middle chainring and brought the bike to the shop for assistance. Turning the front derailleur barrel adjuster counter clockwise eleviated the problem. While in the Granny gear however, the chain rubs in just about every cog with the exception of the largest. I'm concerned considering that the front derailleur barrel adjuster is almost maxed out counter-clockwise! If I adjust the barrel clockwise the chain rub in the middle chain ring persists. Also, while in the big ring I have shifting difficulty when shifting into lower cogs (Shifting up). Considering the barrel adjuster is just about maxed, should the front derailleur cable be replaced? I have no problems shifting down so I assume the rear derailleur has been adjusted accordingly. Please Help! Hope all this makes sense. :confused:
 

·
No, that's not phonetic
Joined
·
14,313 Posts
No sweat. Shift into the granny, and the largest cog in back (lowest gear). Loosen the bolt holding the front der cable to the der, and turn the shifter's barrel adjuster half-way in. Make sure the chain is just barely NOT rubbing the INSIDE plate of the front der (don't worry if it touches the BOTTOM plate- the part linking the inside and outside plate). If there is a sizeable gap between the chain and the inside der plate, pull the der out a bit with your fingers and screw the LOW der stop screw in a bit, release the der, and check for clearance between the chain and plate.

Once that's done, grab the end of the cable with some pliers and pull it snug, and tighten the cable clamp bolt down again. Basically once the der is set to JUST BARELY not rub on the chain when in the granny, it sets the rest of the gears up for some level of success. You can then do some barrel adjust tweaks (since you are in the middle of the adjuster's travel again) to do fine trim work.

NOTE: the front der WILL RUB in some gear combos. That is life. Shimano states this with no remorse! You will NOT be able to use all the gears on the cassette while in the middle chainring without one or two of them rubbing. Period.

Have a nice day. ;)
 

·
Bite Me.
Joined
·
4,531 Posts
Tscheezy has it nailed as usual; however, I have two other thoughts that you may want to check out if your problems persist. Before dialing in your barrel adjusters and re-tightening the cable, check to make sure the front derailleur is securely clamped to the seat tube. I spent about an hour the other day working on a friend's bike and could not get the front der. to shift consistently - after checking the clamp I discovered the derailleur was just a bit loose and would work fine on low tension settings but move around whenever it was being shifted into the bigger rings. If the clamp has come loose you will need to realign it to parallel with the big ring and adjust the tooth gap.

Second, the new 760 front der. clamp arm (where the cable clamps in) can sometimes catch the tail end of the cable between the derailleur body and the clamp arm and give a false setting for the inside reach of the derailleur cage. Again, this was discovered after many aggravating attempts to trim my own front d. Check the length of the tag end on the cable and keep it out of the arm mechanism. Hopefully it's just cable tension, but keep these thoughts in mind as you work on it. Proceed.
 
1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top