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?
--
harper - TANKED at GASWORKS
-Greg Harper
B L U E S H I F T
"My world view has come crashing down like a drunk clown on a giraffe,
riding through a cactus patch..." -evil-nick on "Entry of the
Gladiators"
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