|Campag drivetrain question?||Nuovo|
Aug 5, 2002 5:59 AM
|I just bought a new bike -- actually it's a used Gios frame with new components. It has brand-new last-year's stock Campag Daytona 9 speed components. I love the feel of the ride, but I have some questions... |
I feel a little bit of roughness, kind of a very slight, low-frequency gravelly vibratey feeling, when I pedal with any amount of power, particularly in higher gears. Up on the stand, the bike makes a slight growling noise from the rear mech when I rotate the pedals forward. It's not the out-of-tune stutter, but more of a soft, growly purr. Is this normal?
The reason I ask is that my other bikes have older, 7-speed Shimano 600 and 8-speed Campag Athena bits, and I've never noticed the same kind of thing. They feel much smoother, but it could be that this is all part of the Campag "breaking-in" process. If this is normal, I'll ignore it. If it's not, I'll bring the bike to the shop, though I like to do most of the work myself.
I've checked, and the crankset is bolted on tightly, the bottom bracket feels smooth without the chain, and the pedal bearings seem smooth. Am I being unnecessarily paranoid?
|re: Campag drivetrain question?||JohnG|
Aug 5, 2002 6:18 AM
|Is the upper jockey wheel riding on the cogs?? If so, you need to adjust the B screw or chain the length of the chain.
Was it built with a Campy "C9" chain? Should be stamped on the plates.
What kind of lube are you using. I like Prolink. Use it properly and you'll get big miles and no noise from it.
More details would help. Cog size, short-medium-or long cage der???, etc.
Aug 5, 2002 8:07 AM
|Thank you for the prompt reply. |
I've re-checked the bike. The noise seems to be coming from the freewhub. What seems to be happening is this: as the chain moves the freewheel forward, the freewhub engages and then seems to slip very, very slightly. I checked to see that the cogs are on tightly -- they are -- and everything else seems to be in order. What's interesting is that, although the bike and most of the components are new, the wheels are about a year old.
I suspect that the freehub has worn pawls (is that the correct term?). How much of a tak is it to replace or service the freehub body, and is this something that a reasonably handy home mechanic can do? I do have a spare rear hub that came with the groupset with which I built the, and I'm wonedring if I can just swap that out to use on the damaged hub, without completely rebuilding the wheel.
One more question: The slipping is very slight. I was hoping to ride this bike tomorrow. Aside from the problem of increased wear, is there any danger if I take it for one ride before I have the freehub serviced?
|A mechanic friend came by...||Nuovo|
Aug 5, 2002 10:15 AM
|He said I'm being neurotic. Seems this is all probably just part of the breaking-in process and the slipping that I thought I saw is most probably all in my imagination.|
|Pawls will not wear out in one season!||Kerry|
Aug 5, 2002 4:53 PM
|Check that the chain has not worn to more than 1/16" per foot, that the cog tooth profiles are still uniform, that the chain is clean and lubed, and that the derailleur pulley is not hitting the cogs (would only happen on the small chain ring and largest cogs, if at all). It could also be that the internals of the hube need to be greased. Worn pawls is the most unlikely cause, unless the hub was defective.|
|re: Campag drivetrain question?||curlybike|
Aug 5, 2002 1:03 PM
|Most chains and cassettes seem to get quieter as they first break in. Campy is a little noisier about this. Your results may vary.|| |