I put in considerably fewer miles in January than in the last few months of 2010, mainly because the weather was so uncooperative. But even so, I did come to one major conclusion about my bike:
I have to change cranks again.
Regular readers might remember that my bike fitting in April showed that I needed shorter crank arms. The ones I had were 175 mm, and the fitter recommended 172.5. I was able to change over much sooner than I thought, because guest poster Don Blount had an older crankset that he had upgraded, and was nice enough to send it my way. The difference 2.5 mm made in the pedal stroke was noticeable, and an improvement.
But then came New Year’s Day. The left crank arm fell off during a ride.
I prepared myself after that. I put an 8 mm Allen wrench into my seat bag, ready to tighten the pedal bolt if I ever needed to. Unfortunately, just a few days later, I needed to. I stopped during a ride just to check it, and sure enough, the same left crank arm jiggled a little.
I mentioned the problem to a bike mechanic, and he told me the crankset was shot, and needed to be replaced. I didn’t really want to, and figured I could just tighten it as needed.
But I’ve needed to tighten it more often than I thought. And it’s very unpredictable, too. On a recent 30-mile ride, the bolt stayed tight, even after I’d traveled some grungy roads. But on an easy Veloway ride of half that distance a few days later, I had to stop on the second lap to tighten it down.
So, I’m retrofitting. I still have the original equipment crankset and bottom bracket, and I’ll just swap out one for the other. That means I’ll be going back to 175 mm crank arms. Well, I lived with them for more than two years, and they performed fine – just maybe not as optimally as shorter arms. For the casual kind of riding I mostly do these days, I don’t think it will be a bad thing. Except maybe, I’ll just have to be more careful about lifting the inside pedal on tight turns.
I’m doing some bike restorations at the moment too. New tyres, new brakes, overhauling bearings etc. I’ll drop you a line soon regarding the cranks..
Had a crank-set do that last season. Thought about replacing it when a friend suggested putting some blue lock-tight on the threads of the crank bolt. Went from tightening it every ride to not touching it in eight months. Unless your mechanic checked out your crank and you ovalized the crank-arm from riding it loose too many times, you might want to try and see if a $2 bottle of lock-tight might do the trick.
Bike Noob says
Thanks for the tip. I’ll give it a try.
+1 on loc-tite, unless it’s all wallerd out.