Slow Shifting into Smaller Sprockets
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Slow Shifting into Smaller Sprockets
My new Trek 1.1 is due for its complimentary 1 month tuneup so perhaps this will be answered then. However, for my own edification I wonder if anyone can advise why, when shifting to the smaller rear sprockets, there is hesitation which was not there when I first bought the bike. Think it must be need for lubrication in the derailleur pivots and have tried to inject a bit of lubricant there but what I have done so far has not helped. Shifting up to the larger rear sprockets is smooth but the reverse (shifting to the smaller sprockets) is not.
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try giving the barrel adjuster 1/4 to 1/2 turn clockwise. i would just bring it back to the shop for its 30 day tune up. sounds like something is bent, usually the shifting hesitates going to the larger cogs in the back on new bikes due to the ferrules seating on the housings.
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It's possible that as Reptilzes says you've bent the RD hanger in a tiny bit, possibly in a fall. Turning the cable adjuster a bit will improve upshifting, though since it's due for the LBS free tune up, you might as well let them do it. While there, ask if they're willing to show you the basic adjustments, so you can do minor service yourself in the future.
BTW- whenever you suspect that the hanger may have gotten bent in - the key sign is that the RD trims too far in and slackening the cable cures it - aslo check the inner (L) limit adjustment. When the bent hanger moves the RD in all adjustments are equally affected, and there's now the real risk of the RD overshifting the chain or itself into the spokes, which is an expensive repair.
BTW- whenever you suspect that the hanger may have gotten bent in - the key sign is that the RD trims too far in and slackening the cable cures it - aslo check the inner (L) limit adjustment. When the bent hanger moves the RD in all adjustments are equally affected, and there's now the real risk of the RD overshifting the chain or itself into the spokes, which is an expensive repair.
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WARNING, I'm from New York. Thin skinned people should maintain safe distance.
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Or....Try a thorough cleaning first. Upshifts rely on the main spring in the derailleur, and if chain, cogs, and DR are all gummed up or filthy, things can get slow. Be sure to point this out to your LBS.
#5
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The problem could be friction other than at the derailleur - kinking of a cable housing, grit where the cable passes under the bottom bracket, etc. The shop should pull the cable and make sure all is OK as they reinsert. If not stainless cables I would recommend a bit of spray lube on the cable. If the hanger is bent then the innermost gear (largest cog) will not run smoothly and perhaps overshift, and the others would likely be noisy as well.
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Thanks all. I am going to get the shop to look at it. They are pretty reliable and accommodating. In regard to over shifting toward the spokes to the largest cog I have noticed a sound like it was slightly brushing the plastic cover that protects the spokes. Did not have any falls that could have damaged or bent anything as far as I know. Regarding terminology when I am shifting the rear derailleur to the smallest cog am I shifting "up"? sounds like a contradiction. Also, if I adjust the cable knob clockwise I am giving less tension to the cable, right? Which would allow the derailleur to move outboard to the smallest cog.
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If it hits just right a hanger can be pushed inward just from the bike falling over on it's own or the bike being forced into too small a space when transporting. We had an earlier post on this forum where the poster had that happen when transporting several bikes.
Shifting up refers to the fact that a smaller rear cog means a higher gear ratio.
Yes, screwing the adjustment barrel clockwise effectively shortens the cable housing, therefore allowing more cable between the adjuster and the cable binding bolt, which then allows the derailleur to move outward by spring action. I explained it that thoroughly to show that this type of thing is not something you need to (or should) memorize. If one wants to work on one's own bike, and certainly for anyone who wants to work on other people's bikes, it is necessary to look at how things interact with each other.
Shifting up refers to the fact that a smaller rear cog means a higher gear ratio.
Yes, screwing the adjustment barrel clockwise effectively shortens the cable housing, therefore allowing more cable between the adjuster and the cable binding bolt, which then allows the derailleur to move outward by spring action. I explained it that thoroughly to show that this type of thing is not something you need to (or should) memorize. If one wants to work on one's own bike, and certainly for anyone who wants to work on other people's bikes, it is necessary to look at how things interact with each other.
Last edited by cny-bikeman; 06-21-10 at 07:32 AM.
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