amazinmets73

I had a local bike shop wrench build a bike up from scratch. Upon taking it out on its maiden voyage I discovered the chain was rubbing against the FD. I returned to the shop explained the issue and some adjustments were made. Next ride started off with no rub until I took the bike off tarmac and onto a rough fire road.

What can I do to stop the issue?

Last ride 76 

Depends on what's causing it. Seriously. Cross chaining? Not feathering it properly? Cable stretch? In what front/rear gear combinations does it rub? More information needed.

amazinmets73

OK I'll call the shop tomorrow and ask

fietsbob

If you had a friction shift lever you just move the lever to stop the scraping by fine tuning the cage position.

Wilfred Laurier

And if a frog had longer legs he wouldn't bump his ass a' hoppin'.

As much as I appreciate you have many years of experience with bicycles, lots of your comments are the curmudgeonly 'back in my day' type, and are not particularly helpful.

fietsbob

Shimano's left bar end shifters remains friction.. 8 & 9 speed indexed right side ( 10 & 11 i stopped worrying about)

ridelikeaturtle

I'm not sure how the shop is supposed to know the answers to those questions - you're riding the bike, after all!

Often you can just 1/2 or 1/4 shift the front derailleur and eliminate any rubbing depending on what gear combination you're in. Basically, just slightly moving the front derailleur so it doesn't rub the chain.

robertorolfo

As others said, you have to indicate when it happens, and what equipment you are running.

This doesn't help at all, while on the off chance that the OP is running friction, Fiets post will be perfectly helpful.

CyclingFool95 

For that matter, what groupo are you running? I find Campy 11 is incredibly finicky to set up right but Campy 8, which has about 8 click stops, is cake.

Are you running the right derailleur and chain for the number of speeds? Ie, are you trying to run a triple front with a double derailleur, or a ten speed derailleur with 8 speed chain? Is the chainring jump appropriate for the derailleur - if you're trying to run 16 tooth with an old derailleur meant for 11-13, you might get some issues.

Phil_gretz

Maybe a little more information on what the bike is, and what its gearing is? If the left side is friction, then Bob has it right. If indexed and a triple, then there may be a more complicated adjustment issue. Also depending on whether there are trim settings on the shifter or not.

Phil_gretz

Please - more specifics about the bike, chainset, gearing and shifters?

Last ride 76 

Facepalm here...


I just figured out where the problem is... The shop BUILT the bike. He went in and TOLD them the issue with rubbing FD... If I'm the wrench who built the bike up, I would have the OP show me what he's doing when the rubbing occurs, and then go through all guesses in this thread as needed... including feathering! We're all trying to do it long distance, without even having pictures. May I suggest that you go back to the shop once more, and explain that the problem still exists to some degree, and maybe he can show you how to manage the FD positioning, or cross chaining or... or... etc. Probably take a grand total of 5 minutes (maybe 10) - unless there is a real mechanical problem, in which case, he ought to be fixing it anyway.

amazinmets73

11 speed Campy potenza. 10 speed centaur crank with 11-speed 28 tooth Ultegra cassette