Chain noise

[Rocket_Man]

I am not very good at derailer adjustments to start off with. Anyway...I had my LBS put on new front and rear derailers, and now (about 2 weeks later) the chain rubs on the front derailer...ONLY when its on the biggest chainring...and the smallest gear in the rear. I was wondering how to get that to stop. I believe I would get into that gearing...then turn the H? screw on the front derailer...Till it doesn't make noise??? or does it need to go back to the shop for new adjustment (cable stretch?)

 

[lks]

I am not very good at derailer adjustments to start off with. Anyway...I had my LBS put on new front and rear derailers, and now (about 2 weeks later) the chain rubs on the front derailer...ONLY when its on the biggest chainring...and the smallest gear in the rear. I was wondering how to get that to stop. I believe I would get into that gearing...then turn the H? screw on the front derailer...Till it doesn't make noise??? or does it need to go back to the shop for new adjustment (cable stretch?)

Put the chain on your biggest ring gear and smallest cog. Unscrew the front derailleur outside limit screw a couple of turns. Then tighten your front derailleur cable adjuster, just until you can turn your crank without the chain rubbing on the derailleur cage. Now screw the limit screw back in just until you feel resistance, and you are done. You don't want adjust the front derailleur out any further than what eliminates chain noise, because you risk having the chain fall off the big ring, on the outside. The front and rear derailleur limit screws should only be adjusted with no derailleur pressure/contact on them because their threads are not made to exert force, only stop/limit it.

 

[alfeng]

I am not very good at derailer adjustments to start off with. Anyway...I had my LBS put on new front and rear derailers, and now (about 2 weeks later) the chain rubs on the front derailer...ONLY when its on the biggest chainring...and the smallest gear in the rear. I was wondering how to get that to stop. I believe I would get into that gearing...then turn the H? screw on the front derailer...Till it doesn't make noise??? or does it need to go back to the shop for new adjustment (cable stretch?)

Sounds like CABLE STRETCH ...

Hopefully, you haven't made adjustments to the derailleur's stops, yet ...

Put the front derailleur on the inner ring, and take the slack out of the cable ... if you have adjusters on the downtube, use it/those.

 

[Rocket_Man]

Thanks for the help...yeah, its been a while. I just kept it out of the gear that made the noise. It was a little bit of both, cable stretch and rubbing. Pulled the cable tight...still made a little noise, adjusted the screw (1/2 turn) and now it is quite as ever!!!

THANKS