I received an Airfoil wheelset from unicycle.com on Friday, 20 May 2005. Since it was supposed to be delivered 19 March 2005 and March and May both start with “Ma” I figure it was only a day late.
This wheelset was built up with 12 gauge spokes by John Kovachi and is not to be confused with the super-elegant, super-strong Dave Stockton wheel laced with 14 gauge SS spokes. I had the 100mm wide CroMoly axle included as part of the wheelset.
It came with cranks attached, which I didn’t expect, so that may be a plus if I didn’t pay for them. It had rim tape installed which I covered with vinyl electrical tape to make it slippery. I have had a new tire ready for this rim for almost a year.
I installed the tube and tire dry (using no lubricants) but used two plastic tire irons in the process. I was hoping to do it by hand only but I’m a sissy so resorted to tools. When inflating, I had trouble getting the bead to center on the rim but several pressure cycles slowly centered the tire on the rim.
I spread the frame forks slowly with one wrapped in cloth and lightly clamped and in a vice and pulled the other fork. I wanted to just fit over the axle and when forced onto the bearings have the forks tend to push the bearings inward to avoid bearing drift. This is probably a fantasy because sitting on the saddle probably splays the forks out anyway.
When I attached the bearing clamps I rotated the wheel and heard a slight but distinct scraping every revolution. The wheel was well trued and turned nicely in the old frame. I watched the assembly carefully when I located the position in which the scrape and drag occurred and found that the spokes protruded far enough to occassionally rub the old, original Coker frame just above the hub and the bearing clamps.
My first instinct was to use a rattail file to file away 0.050" (1.25mm) right at the points on the frame where the spokes rubbed. I then realized this would remove the chrome plating in this region and subject the frame to rust at those two spots. So, like any rational person, I went to bed.
Today I attended a funeral and had time to think of other options as well as dead people. I decided to put a cylindrical dimple in the frame at the two spoke contact points. I would back the outside of the fork being dimpled with wood to conform to the irregular fork shape under pressure and distribute the force on that side. I would create the dimple with a steel or brass round of about 0.5" diameter placed at the point at which the spokes scraped the inside of the frame.
I measured the frame thickness of the oval tubing at the point of interest to be 0.650" (16.25mm) . I measured the vice travel per handle revolution to be 0.100" (2.5mm) and my goal was to put a 0.100" dimple on each inner side. I set up the wood, steel round, and fork in the vice. I tightened the assembly and put on the squeeze and, voila, there was a cylindrical dimple along the inner fork at the scrape point and the thickness measured 0.550" (13.75mm) and was just slightly crooked. the second side I did straighter.
No click, no scrape, no fuss, no machine shop, and, most importantly, no chrome plating loss. I am wondering if swaying in the frame will continue to allow the spokes to occassionally contact the frame but there is quite a bit of clearance now. Well, I would just have to do a frame upgrade then, eh?