Friday, July 02, 2010

Freeze Frame

The first time I saw bike tubing swollen like frozen plumbing I was amazed. Someone who had ridden his mountain bike hard and put it away wet pulled it out of his unheated shed in the spring to find that the tire clearance had shrunk and the gears skipped. Since then I've seen the effect several times. This is the latest victim.
The drive side chain stay expanded enough to rub on the 1.95 tire. The expansion of the stay spread the rear dropouts about half a centimeter. Amazingly, the metal did not split. One might attempt to crimp the stay again, using a shaped block, a metal cylinder and a vise. If the metal did not split from that stress you could run wide tires again. Or you could leave the stay fat, tweak the dropouts for spacing and alignment and just run 1.25" street tires.

It looked more dramatic before I chipped the paint away to examine the metal.

I go from stuff like this to grimy NEXT or Walgoose suspension bikes to a bright new Cervelo and back to a 1995 Specialized Hardrock.

Cervelo Dude was on a ride and had a shifting problem. He had a SRAM drive train with barcon shifters on aero extensions.

"I just got this wheel set," he said, pointing to the brand-new Zipps. "It's not getting the low gears."

The rear derailleur had a mile of adjuster barrel hanging out.

"Who adjusted this?" I asked.

"The guys at my local shop," he said.

Hmmm. Adjuster tuning. A sign of laziness or lack of knowledge.

The top tube was the only somewhat round tube on the entire bike. I didn't want to alarm him by stuffing that into the jaws of our old skool Park work stand, even though I know enough to pad things and use zero clamping pressure. Fortunately the bike's saddle had a hooked nose. I was able to hang it over the padded arm of the work stand securely enough to tidy up the gear adjustment. Cervelo Dude resumed his ride and I returned to the gritty, mundane steeds of the common folk.

George is back from his trip to Nova Scotia, so we go into the holiday weekend with extra wrenching capability. Time to get out of my PJs and into my battle armor for the ride to work.


Steve A said...

Cafiend; plumbing the depths of yet another fascinating bike malady I have never seen. Bravo!

Ham said...

I know you appreciate the finer points of illustration

Anonymous said...

Just thought I would let you know that your blog is one of the most interesting I read.

its like an anthropological look at the world of the bike shop worker.

cafiend said...

Ham: Their minds work like mine and their pens work better.

Anonymous: I often feel like I'm doing an anthropological study, so thanks!