Midaregami

I have not talked about it a great deal, but the bicycle project has continued. Not only have I ordered the balance of the parts I need to complete the device, I have also built the wheels.

This is actually a big deal. Bicycle wheel-building is regarded as one of the most difficult tasks within the purview of the bike mechanic, second only to frame design and fabrication. I was hesitant to try for that reason, but when my hubs were delivered recently, I decided to give it a go.

There are essentially three steps to building a wheel: Lacing, tensioning, and truing. Lacing involves threading the spokes through the hubs and connecting them to the inside of the rim. Tensioning involves tightening the spokes, and through the truing process one makes minute adjustments to the tensioned spoke to make the wheel “true”—that is, perfectly round and without and lateral bulges or wobbles.

It’s a tricky process. Spokes have to be threaded over and under each other (I used a traditional “cross-three” lacing pattern) to give the wheel strength. Particularly in the case of the rear wheel, radial strength and torsional strength are both critical, so the spokes that resist the twisting motion applied by the drivetrain have to be in a certain direction for optimum strength.

The truing process is not unlike tuning a drum—minutely tightening or loosening adjustors to achieve an overall balance. It requires concentration and patience, since one adjustment may throw a wheel out of true in other places around the rim.

So, without a truing stand or dishing tool, I (perhaps foolishly) set about the task with only my bike frame as a stand and my thumbnail as a truing guage. Two days later, the wheels are built, tensioned, and true to within a millimeter, both laterally and radially.

It was an almost religious experience. In the process of trying to achieve perfect roundness, I discovered patience and attention to detail I never knew I had.

This entry was posted on Saturday, June 25th, 2005 at 2:06 pm and is filed under Geekery. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.