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Poor shifting among bigger cogs(7 posts)

Poor shifting among bigger cogsvelocity
Aug 9, 2002 8:37 AM
On a bike equipped with Campy Veloce 9-speed when I shift among my biggest cogs it's not smooth and occasionally there's slippage down from bigger to smaller cog. Chain has >3,000 miles on it but is in good shape. What would you recommend doing to improve my shifting? Needless to say, it's a real annoyance when climbing.
Assuming that you're "barrel adjuster literate".Spoke Wrench
Aug 9, 2002 8:59 AM
My first guess would be the dropout is a little bit out of alignment.
Dropout out of alignment?velocity
Aug 9, 2002 3:29 PM
Have been trying to adjust the barrel adjuster. No luck. May just bring it to the LBS. The crux of the problem is that when I'm in small front ring and either of the two biggest rear cogs the chain rubs against the front derailleur.

How can I check to see if the dropout is out of alignment?
Many adjustmentsKerry
Aug 9, 2002 5:22 PM
If the chain rubs on the front derailleur when on the small ring and big cogs in back, you need to adjust the lower limit screw and/or the barrel adjuster to allow the FD to move closer to the frame. Does the chain drop to a smaller cog when you're pedaling hard, or JRA? When you adjusted the rear derailleur, did shifting not improve at all? Did the smaller cogs shift worse? You say in your original post that the rear shifts by itself, but now you say the crux of the problem is FD chain rub. Which is it? FD chain rub will not cause the rear to shift. If the dropout is properly aligned, the pulleys of the rear derailleur will be vertically in the same plane and perpendicular to the hub axle. If the RD is canted toward or away from the center of the bike, then the derailleur hanger is bent. Did this problem come on all at once, or has it crept up on you. If it came on instantly, that suggests something got bent (a crash, transporting the bike in the car, bike fell over in a bike rack, etc.).
Yup.Spoke Wrench
Aug 10, 2002 11:35 AM
Rubbing on the front derailleur is a different problem. Your front serailleur definitely needs to be adjusted. If your chain is slipping, I still suspect your dropout needs to be aligned. If I'm right, that's two separate problems. Frankly, it sounds to me like you are in a little over your head. I'd suggest taking it to your local bike shop and talking to the oldest guy working there.
All advise very helpfulvelocity
Aug 11, 2002 8:45 AM
Since there doesn't appear to be a simple solution, I am probably in over my head. Was hoping to resolve my shifting problems with the help of the Zinn book and a bit of help from you guys. How else does one learn but by trying to figure stuff out? Know an excellent mechanic and will bring that bike over to him. Thanks.
Try ThisBigLeadOutGuy
Aug 9, 2002 9:12 AM
put a drop of oil on the metal cable guide thats on the bottom of your bottom bracket. Sometimes the friction between the metal guide and the cable along with some frame flex makes your rear der. shift on its own. Put a drop of oil on that cable guide and it just may solve your problem.
hope it helps