I recently built some Airfoil rim/UDC hub Coker wheels using Tommi's
spokes and the Semcycle nipples. In addition, I used Sapim Spoke Washers
between the nipples and rim, which increases the length spoke required
by about 1/2 mm. I did not use any of the standard spoke calculators,
but made my own measurements of the rim and hub. I consider a spoke the
"correct" length when, under tension, the end of the spoke is flush with
the bottom of the screwdriver slot in the nipple.
For 3-cross, I ordered 14 7/16 spokes. They worked well and I would do
it again. I think you'd be ok anywhere between 14 3/8-14 7/16ths.
I later built a wheel for someone who already had a set of 14.710 spokes
as 4-cross. They worked, but I considered them slightly short as some of
the threads were visible adjacent to the nipple. If I did it again, I'd
go with an even 14 3/4", but my personal preference is for 3-cross.
I wouldn't worry about going slightly long and having the spoke protrude
through the nipple and into the tube -- with the Airfoil rim, the tube
doesn't really get anywhere near the nipple. The risk is that you run
out of threads on the spoke before you reach a high enough tension.
Tommi normally puts "extra" threads on his spokes above the standard
10mm. The Semcycle nipples are long and require these extra threads.
I really like the Semcycle nipples; the 12 gauge body lets you reach
pretty high tensions compared to a bicycle wheel with less risk of
rounding-off the nipple body. Since the rims are drilled for 12 gauge
spokes, you really need these special nipples or some sort of washer. I
tension the spokes at around 1900 Newtons.
--
adelman - What mud?
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