After a few years of training on the road with a powermeter, I finally ponied up and bought a powertap mountain bike hub. I wanted to go as light as practical, so I built it up with a Stan’s Crest rim and DT Aerolite Spokes (still went with brass nipples, though). At first, I put a cassette on it and put it on my geared bike. However, after a little thought, I realized that I won’t really be riding the geared bike much in the upcoming week or two. So, I pulled the cassette, slapped a 21t cog (for Syllamo next week), and put it on my singlespeed.