Road Cycling - rear derailleur question

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GreyHair
09-11-04, 04:18 PM
I just replaced my rear wheel and was looking at the adjustment on my rear derailleur. I think I adjusted the travel correctly but the derailleur does not come back to bring the chain to the smallest chain ring. If I understand the mechanism correctly a spring is supposed to accomplish this. Is this an indication that the derailleur needs replacing or is there something else I can do?

sydney
09-11-04, 04:39 PM
I just replaced my rear wheel and was looking at the adjustment on my rear derailleur. I think I adjusted the travel correctly but the derailleur does not come back to bring the chain to the smallest chain ring. If I understand the mechanism correctly a spring is supposed to accomplish this. Is this an indication that the derailleur needs replacing or is there something else I can do? www.parktool.com has deralier adjustment in the repair section. Try loosening the cable ,with the chain on the small cog,and see if the derailer moves,when turning the correct screw counterclockwise.
RonH
09-11-04, 05:19 PM
Take a look at this >> http://www.parktool.com/repair_help/FAQrindx.shtml.
Sounds like the limit screw needs to be adjusted ever so slightly.

Retro Grouch
09-11-04, 06:46 PM
How did it shift with your old rear wheel?

If it was sluggish before, you probably have crud in the cable housings and a fresh set of cables and housings will do wonders.

If it shifted fine before, you probably need just a touch of high limit screw adjustment. Now here's the trick. Often just adjusting the limit screw won't fix it because cable tension is also keeping the derailleur from moving out far enough to access the smallest cog. Don't be surprised if you have to make a cable tension adjustment also.
East Coast Mojo
09-11-04, 07:59 PM
I would open the QR with the bike on the ground to make sure the wheel is fully seated in the frame. Let the weight of the bike push the axle all the way into the dropout. Check the integrity of the hanger and cage by trying to move the derailler cage back and forth gently. If it wiggles a lot you may try tightening the hanger screws and if that doesn't fix that you may need a rear derailleur.

Adjust cable tension first, a good test is to loosen the cable at the anchor bolt completely and pedal the bike forward. If the chain drops down it is cable adjustment. Then the limit screw if necessary... ;)