Punked

The wily Shimano DH-3N72 dynamo hub. It's capable of generating 3 watts at 10+ mph. It will power your  LED headlight and vex your wheel builder, because its dimensions are so damn hard to find. For the record: 70mm for the spoke circle diameter, and 28.5mm center-to-flange. There are a variety of Shimano dynamo hubs other there, so don't assume those measurements apply to yours. I like the dynamos: they will light the road, but won't lighten your wallet or your bike.

Recent wheel building adventures since my last blog entry:

• Discovering the spokes were too long on the dynamo wheel I am building for my dad. The wheel was laced, the spokes were at 80% tension, and I was finishing off the wheel when I stripped a brass nipple. That should've been my first sign that something was wrong, because an aluminum rim will fold itself into origami before a brass nipple will strip. I cut the stripped spoke, threaded in a new one, and continued to the next spoke. That one also started to strip. Once I figured out that I had run out of threads on the spoke, I took the wheel apart and measured the spokes. They were 286; I needed 283. Tip: always measure your spokes before a build. You wouldn't believe how many times there will be an oddball length in the lot.
• The joy of carbon rims. As noted in previous posts, tall rims are exceptionally rigid, and as such they can mask vast discrepancies in spoke tension. Last night I finished the 50mm carbon tubular with the assistance of the Park Tool spoke tension map. The map made it a lot easier to spot under/over tensioned spokes, even though the rim was within truing stand tolerances.
• Losing the will to live. There's no worse feeling--in wheel building--than finding a fatal flaw once a wheel has been assembled. It happened this week with that super cool elbows-out front wheel I built. During the final truing it became evident there was excessive play in the axle/bearings/hub body. It was only a millimeter but that becomes amplified at the rim so much so that the final truing becomes impossible. Fortunately, my supplier was understanding and immediately dispatched a replacement hub. Still, that was a couple hours down the drain.
• Black spokes. I built my first wheelset with black spokes because I thought would look sweet. (It did.) That set: HED Belgian C2 rims, White Industries H2 & H3 hubs, DT Swiss Competition spokes, 32 hole and 3 cross all around. I vowed not to use black spokes after that because the coloring creates additional friction where spokes cross. That stiction is a small but annoying annoyance when tensioning a wheel.

In the queue:

• The best wheels of 2013 (aka Tod's wheelset).
• Gigantex carbon tubular rear/24 hole/White Industries T11. This rim has a spoke tension limit of 130 Kgf. Gigantex is arguably the best mass market Asian-sourced carbon rim. It is made in Taiwan. They don't sell direct to consumers, but the Bicycle Hub Store does stock them in 38mm and 50mm. (I also believe they are center-drilled for those of you with 2:1 spoking aspirations.)