I am having allot of difficulty with the front derailleur setup for my new >compact crank. The chain will rub the outer plate (right side) of the >front derailleur when it's in the small or big ring up front and in the >middle (!) of the rear cassette.>
I had the bike shop adjust the derailleur twice and I did so once myself. > I am at the point of scratching my head what to do next. It's very > frustrating.>
The bike setup is a 50/34 crank, Ultegra 9sp (6500) front derailleur, STI > shifters and a 12x27 9-speed cluster in the rear. The derailleur cables > are new and the rear shifting is perfect.
Could be that your front derailleur is actually too low (too close to the chainrings). Try moving it up just a bit and see if that helps.
The front derailleur limit screws seemed to be setup correctly; shifting > to and from the rings is fine. The number of usable gears is very limited > though. For instance the 3 or 4 smallest cogs are off limits while in the > small ring due to too much chain-n-derailleur grind. Trimming wont help. > One notable item is that the cable tension must be set real high.
Too-high cable tension is nearly always a sign of a misadjusted front derailleur (on a Shimano STI system). If the tension is too high, you're unable to "trim" the large chainring. If you are able to trim it, then the tension probably isn't too high.
I just checked my own bike (a Trek 5900 with FSA carbon 50/34 front, D/A front derailleur and 12/27 rear), and notice that the trailing end of the front derailleur is just slightly inward (toward the frame) compared to the front. This is a slightly-different position than you'd set up normally, but it works very nicely on my bike.
"Sir, It's Just Me" <nospam?@thanks?.?> wrote in message news:zv4%d.7555$ZB6.5982@newssvr19.news.prodigy.com...>I am having allot of difficulty with the front derailleur setup for my new >compact crank. The chain will rub the outer plate (right side) of the >front derailleur when it's in the small or big ring up front and in the >middle (!) of the rear cassette.>
I had the bike shop adjust the derailleur twice and I did so once myself. > I am at the point of scratching my head what to do next. It's very > frustrating.>
The bike setup is a 50/34 crank, Ultegra 9sp (6500) front derailleur, STI > shifters and a 12x27 9-speed cluster in the rear. The derailleur cables > are new and the rear shifting is perfect.>
It's a Nashbar labeled compact crank made by "RPM" which is the same > Taiwanese company that makes FSA cranks as far as I can tell from doing > some research on the web. I have a 68x108mm ISIS bottom bracket installed > and the q-factor is spec'd at 160mm.>
The front derailleur limit screws seemed to be setup correctly; shifting > to and from the rings is fine. The number of usable gears is very limited > though. For instance the 3 or 4 smallest cogs are off limits while in the > small ring due to too much chain-n-derailleur grind. Trimming wont help. > One notable item is that the cable tension must be set real high. This is > more so than I've had to do with past bike setups. While riding the bike, > shifting from big to low or low to big, I would always have to trim the > front derailleur.> This is so even when the chain is in the middle of the rear cassette.>
After putting a few miles on the bike, eventually trimming the shifter > would not be enough. I'd still get the grinding noise even while the > chain is residing in the middle of the cogset. Retightening the cable > tension helped alleviate this problem only temporarily and the cable clamp > torque is definitely adequate.>
Any suggestions as to what I can do? I wish for the day I could ride in > peace. I'd rather be grinding coffee at the moment instead of my > derailleur. Thanks for your help!
