Front Mech Adjustments

[Jdratcliffe]

i had a different LBS service my bike the other week ( never again) and now i have chain rub on my front mech when im in the lower half of the top gears, i have trried trimming the high limit screw but if i trim it so it doesnt rub the chain wont change up...?

ideas please... pics below

 

[boydj]

It can be tricky getting the front mech set up correctly. You need to find the combination of angle, height and lower limit setting as the start point. In your case, the angle is set as it's a braze-on mech, and we'll assume the height is ok. This means you may need to adjust the lower limit setting after releasing the cable and then re-attach the cable. Since the amount of cable that the mech will pull is fixed, you need to have the starting point high enough that it will shift onto the big ring, but not so high that you'll drop the chain, and not too high that you can't get the chain back onto the small ring.


It can take a few tries to get it right and you may have to accept a little bit of rubbing at the extremes of the cassette. Sounds like a lazy LBS.

 

[musa]

you probably know it already but it dont hurt

 

[simon.r]

Y'know when people say there's no advantage to singlespeeds...

 

[subaqua]

www.techdocs.shimano.com

 

[actonblue]

Take the bike back and have them look at it again. You have paid for a service and it should have been done correctly. Don't waste your time rectifying it yourself because if you could do it you would not have paid to have it done in the first place.