Monday, June 09, 2003

Aborted Bicycle Commute- 2 miles

OK, ever since I had the Dura Ace (9-speed) chain put on my Eddy Merckx (see blog dated 5/6/2003) it's been nothing but trouble. Eddy has 8-speed Ultegra shifters and rear derailleur with a Campy Athena crank and front derailleur (I used this setup with 8-speed chains without problems for years before I bought my Klein). Anyway I was throwing the chain nearly every ride and it was really pissing me off. I adjusted and readjusted my front derailleur and it would seem fine on the workstand but I would still throw the chain on the road. So today on the way in to work I shift up to the big ring and it goes all the way over and down the crank arm. I tried the old downshift and scoop maneuver but it got worse so I had to stop. The chain had completely knotted up and I had to take my wheel off just to straighten it out. Of course I gouged a finger on a crank tooth while I was doing this. Wheel back on, chain unknotted, hands filthy with chain gook I set off for the rest of the trip and … more problems. Somehow I managed to twist a link in the chain as well and it made the bike almost unrideable. I limped back home, washed my hands, and got the car keys.

Lesson learned: 9-speed chains should be used only on 9-speed drives.

From Shimano's FAQ:
The 9-speed chain is ~0.5 mm narrower and so is the front derailleur cage.
Using a 9-speed chain with 8-speed front derailleur and crankset will result in sluggish shifting and the adjustment is more critical. You may have to continue to hold the shift lever in an "overshift" until the shift is complete. In the worst case, some 8-speed chain rings have shown a tendency for "chain jamming" during downshifts with a 9 speed chain.

The Performance catalogue even has a note not to run Shimano 9-speed chains on 8-speed drivetrains. Sheesh. I gotta go buy a new chain.