Saturday, July 08, 2006

tandem fun

A while back the re-Cycles Bicycle Co-op received a donation of an old CCM tandem. Single speed with coaster (back-pedal) brake, old 26 x 1 3/8 wheels, probably built back in the 1960s.

Upon close inspection at the shop we noticed that the top and down tubes had been re-welded to the head tube. Also, even though the frame was very clean there was rust on the bottom tube, and even a small split in the metal about 1/2" long. So, the bike couldn't be sold until that was dealt with. I brought it home, hoping to eventually get it to Juergen's (he did the welding work on my cargo trike) so we can braze on a sleeve or some other kind of fix.

In the meantime, I put two hose clamps around the split so that the bike could at least be taken out for some rides to see was it was like. The verdict? The crappy front sidepull brake did not do a very good job, even with better pads. The coaster brake was also not very good, needing an overhaul. Also, one speed meant for a workout on such a heavy bike. So I got an idea...

One of those modern cruiser replica bikes had come into re-Cycles, with damage to the front end. But it did have a very new Sturmey-Archer 3-speed rear wheel with coaster brake! So, that came home for the tandem, and I realized that since it was a mtn. bike 26" wheel (ISO 559) I should change the tandem's front wheel to match it. This meant changing the fork, and a side benefit to that was it allowed the fitting of a modern V-brake for much better stopping power (and the new back-pedal brake is great as well). And as I thought this through I got an even more brilliant (or twisted) idea - use a suspension fork! The re-welded head tube gave ample evidence of the front end not liking the stress of bad bumps, and suspension would ease that. So I found a cheap fork, changed out the headset, and voila:

(yes, that's a cheap cable lock around the front end)

definitely has a bit of rake to it...

ding-dong bell for captain, honky bulb horn for stoker

shiny almost-new 3-speed

3-speed cable routing to cope with frame tube layout and double chain set-up

Verdict? Much better! Also, I added quick-releases to the seatposts so the bike could easily be adjusted to different rider sizes. The stock fenders had to come off, but I was able to squeeze the cruiser's fat rear fender in there. I could not make any fender I had fit the front end due to tight clearances, so on a rainy day the captain gets wet toes. The 3-speed could use a larger cog to lower the gearing a bit, as 3rd doesn't get used all that much, but that's a mod for another day...

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