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#1 |
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Registered User
Join Date: Jul 2005
Posts: 7
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Hi,
I have purchased a second hand Giant OCR 2003 with Campag Mirage kit on it The bile was a bit grubby, but that cleaned up nicely to reveal a bike that appears to have done little mileage I do however have a problem where I cannot set the rear mech up correctly I can set the gears up so that the smaller cogs are running smooth but it rattles on the larger cogs or the other way around Any ideas would be gratefully received at this point |
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#2 |
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Registered User
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1) Check for chain stretch and cassette wear.
2) Make sure the cables are running smoothly and not hanging up on anything. 3) Campy has the whole run down for adjustments here: http://www.campagnolo.com/pdf/72251..._derailleur.pdf |
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#3 | |
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Registered User
Join Date: Jul 2005
Posts: 7
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Quote:
Thanks for the reply one thing I should have mentioned is that you can manually move the rear mech and all the gears are selectable with no problem Also by pulling the cable from the down tube all the gears are selectable one by one It is when the ergo leavers are clicked that I have the problem The cables seem fine - I have renewed the inner cable and lubed the outer cables (although I have no idea what state teh cables are internally) |
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#4 |
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Registered User
Join Date: Jun 2005
Location: CT, USA
Posts: 249
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some sanity checks:
1. when you say lube the outer cable do you mean putting grease or oil in the cable housing (approx 1/8" thick, hollow). 2. make sure the rear drop out is tight - when you remove the rear wheel you'll see a screw holding it on. 3. make sure the cable is clamped on the correct side of the anchor bolt. 4. lube the rear derailleur thoroughly so that it freely moves through its range of motion. 5. lube the shifter thoroughly as well. if you look at a diagram of the shifter, lube the thing the cable wraps around, not the pivots for the braking part of the brake lever. If the derailleur is clicking in one end of the gears but not the other, then either the derailleur and shifter are not compatible or the derailleur is a bit bent. Manually moving the derailleur and getting all the gears indicates the limit screws should be okay (else you wouldn't get into the small or large cogs). The clicking indicates that the derailleur is moving a different amount sideways than the shifter wants it to move. some more detailed checks: 1a. from behind, pull down on the rear der cage until it is vertical (so the two pulleys are vertical anyway). usually derailleurs get bent inward. if you notice more than about a half of this tilt --> / then grab the lower cage and gently but firmly flex it outward about 1/2". it should pop back about 2-3 mm (1/16"?) more vertical. 1b. in the small small combination (for example, 39x12), the rear derailleur cage should be almost horizontal. does it point straight fore/aft or is it noticeably skewed one way? try tweaking it the other direction. 2. when in the smallest cog (all the way to the right), wiggle the rear der. It may be loose, i.e. there is play in the various pivots. If there is play you may need to replace the derailleur. (the same test applies for the front derailleur). one of the unseen but expensive features of a derailleur is the quality of the pivots. Less expensive derailleurs of all makes have inexpensive, cheap, and short lived pivots. expensive derailleurs have much stronger pivots and last a lot longer. 3. are the clicks in the shifter solid? are they similar from the left shifter to the right one? if they feel different (and the right side is softer as it usually is) then you may need to replace the springs in the ergo lever. worst case is the gear wheel itself is worn/chipped. neither is a major deal but it involves removing the lever in question. this means retaping the handlebar and removing the shift cable (which if it's frayed at the end means replacing it). 1 hour for the first time you do it, 30 minutes from then on. hope this helps |
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#5 |
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Registered User
Join Date: Oct 2003
Posts: 5,151
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Have derailer hanger alignment checked. If hanger is bent,you are wasting your time trying other fixes.
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#6 | |
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Registered User
Join Date: Jul 2005
Posts: 7
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Quote:
Thanls for the suggestions - I will let you know how I get on |
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#7 | |
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Registered User
Join Date: Nov 2003
Location: Central Coast, Cali.
Posts: 443
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Quote:
Exactly what I was going to say ![]()
__________________
*The energy efficiency of a bicycle is second only to a bird in flight ;-) *Its NOT a mechine, its a tool. A human using a bicycle as a tool-as intended .. now thats one wicked Mechine (ex. legs = pistons, mouth/airway = air intake) *"Good people try to help others with their knowledge rather than beating them on the head because they are ignorant." -Insight Driver |
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