Bicycle Mechanics - Rear Derailleur lazy on big cogs

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nomo4me
08-01-05, 12:31 AM
When shifting onto the largest two cogs while in the big front chain ring shifting is delayed and "lazy". Shifting back down poses no problems.

Brifters and rear der are both Dura Ace less than 6 months old. Bike and components are clean. Cable is lubed.
I suspect it's a cable tension issue. Can someone tell me how to correct it?

MattP.
08-01-05, 12:45 AM
The problem is probably that you never want to be in your largest cog and you largest chainring. And it will usually be "lazy" there. It stretches out the chain to much. Just try to aviod that combo. Also aviod the smallest cogs and the smallest chainring.
nomo4me
08-01-05, 12:48 AM
The problem is probably that you never want to be in your largest cog and you largest chainring. And it will usually be "lazy" there. It stretches out the chain to much. Just try to aviod that combo. Also aviod the smallest cogs and the smallest chainring.

Eh, I got that wrong in my post. I'm not cross chained.

Crank It Up
08-01-05, 12:52 AM
Almost all modern rear derailleurs are capable of shifting to largest rear cog while on the large chainring with proper adjustment of the limit screw BUT you're looking at excessive drivetrain wear. Also make sure that the RD cable is pulled taut while in the smallest rear cog. Fine tune it with the cable barrel adjuster.
BostonFixed
08-01-05, 06:49 PM
You need to tighten the tension on your rear der. cable. Find the adjuster at the rear der., and turn the adjuster counter-clockwise, as if you are loosening the adjuster. Do it in small increments at first (1/4 turns), and check shifting. Repeat as necessary. Be patient, and you can get it adjusted really well. It's not too hard.

Rear der. adjuster is what the fingers are touching in this pic:
http://www.mothernature.com/images/library/books/CyclingWomen/CFW1503.GIF
nomo4me
08-01-05, 08:08 PM
You need to tighten the tension on your rear der. cable. Find the adjuster at the rear der., and turn the adjuster counter-clockwise, as if you are loosening the adjuster. Do it in small increments at first (1/4 turns), and check shifting. Repeat as necessary. Be patient, and you can get it adjusted really well. It's not too hard.

Rear der. adjuster is what the fingers are touching in this pic:
http://www.mothernature.com/images/library/books/CyclingWomen/CFW1503.GIF

Thanks. Will delve in :)