One of my friends swears that wheels I built for him roll
faster than other wheels. He says he has even tested it with similar tires at
the same pressure, trading wheels with another rider. He has said it enough
times to enough people that I believe him. His tests are on long, steep hills
with no pedaling but no brakes either, just coasting. And no matter whose bike
has the Earle Wheel on the front, that’s the one that rolls away from the rest.
I build my wheels for maximum reliability and durability,
but I had not really thought about making them roll faster. But as I mulled
over the findings, I realized that the same things I do to make a strong,
long-lasting wheel also make the wheel roll faster. Spoke tension.
Specifically, very even spoke tension makes the wheel roll a little bit easier.
A trained engineer who studies wheels could certainly say it
better than I can, and will have numbers to back up the words, but for the
average rider, that would be overkill.
The thing to remember is that when it is rolling, a wheel is
not really a static structure. As the wheel rolls, each spoke loses a little
bit of its tension, then regains it. When a spoke that is significantly looser
or tighter than its neighbors, the oscillation of tension is enough different
that slows the bike down ever so slightly, the way a small bump in the road
would.
We all know that smoother roads are faster. Well, my story
(and I am sticking to it) is that wheels with very even tension will roll more
smoothly and faster, the same way a bike goes faster on smooth road.
