Saturday, August 8, 2009
London Edinburgh London 2009 Stories -- Crank Problems
You've heard the advice many times -- don't change anything on your bike before a big ride. Still, I had a lot of miles on my Coho's drivetrain, so I had Ed, my trusty mechanic, put on a new cassette, chain, as well as an FSA bottom bracket and crankset, which is one of those modern designs with the outboard bearings. All seemed fine on the 100-mile test ride here in the states, and on a 20-mile trial run on the LEL course.
So what happens on the ride itself? I'm probably 15 miles in and I can no longer shift into the large front ring. Thinking I had a derailleur or cable issue, I stop to check things out. The crankset now has as 1/4-inch of side-to-side play -- so much that it slides to the right out of range of the front derailleur's ability to put the chain on the large ring. I knew how to tighten it -- loosen the bolts on the left crank arm, tighten the crank arm cap bolt. But I didn't appreciate the subtleties involved. I should have loosened the crank arm bolts more. The volunteer mechanics along the way were more like me -- they knew all about the old school square taper bottom brackets, but were pretty clueless about these new-fangled designs.
Bottom line: I never really got it right and had to stop, sometimes as often as every 100K, and readjust. In my lowest moments, I wondered whether this mechanical issue would be a show stopper. But I lived with the annoyance and got er done. Lesson learned -- leave well enough alone before the ride or get a quick lesson in roadside repair beforehand.
Apart from that issue, the bike performed flawlessly and was a delight for the entire 1400K journey. A special thanks to Chuck for building such a fine randonneuring machine.
I keep looking longingly at those outboard bearings and keep thinking they'd be nice. I may yet go for it, but I'll time the decision appropriately thanks to this advice.
ReplyDeleteI was very thankful that you had that recurring mechanical problem with the crank. Every time that you stopped to tighten it I would catch up with you again.
ReplyDeleteDear Mike,
ReplyDeleteI had the same experience on a traditional bb/crankset on a recent 280mile ride. I had almost 1K miles on the BB installation when it worked loose on a 30mile climb. DNF. Sometimes you just get unlucky. Congratulations on your finish!
Best Regards,
Will
William M. deRosset
RUSA 2401