- #1
carlfogel
- 11
- 0
Hello,
Typical bicycle wheels have 36 spokes that are
trued to a final tension of roughly 200 pounds.
If a pair of adjacent spokes are squeezed together
with one hand with a force of roughly 100 pounds,
what does the spoke tension rise to?
I'm asking because this healthy-squeeze operation
is popular among some wheel-building engineers,
who believe that it relieves stresses and is crucial
to preventing fatigue-broken spokes. They may be
right, but data, details, and testing are not forthcoming.
So far, I'm just trying to figure out how high the
tension rises. That is, does the existing 200 pound
tension rise to 250 pounds, 300 pounds, 400 pounds,
or what?
This spoke question may be different from the classic
example of tension in a previously slack horizontal rope
after a weight is added, but I'm not sure whether the
pre-existing 200 pound tension matters.
If it's of any importance, the stainless steel spokes
are about 295 mm long, 2 mm thick, and stretch about
1 mm under 200 pounds of tension. My best estimate
of the angle of deflection under a 100 pound sideways
force is 4 to 5 degrees from the ends of the spoke to
the center.
Thanks,
Carl Fogel
Typical bicycle wheels have 36 spokes that are
trued to a final tension of roughly 200 pounds.
If a pair of adjacent spokes are squeezed together
with one hand with a force of roughly 100 pounds,
what does the spoke tension rise to?
I'm asking because this healthy-squeeze operation
is popular among some wheel-building engineers,
who believe that it relieves stresses and is crucial
to preventing fatigue-broken spokes. They may be
right, but data, details, and testing are not forthcoming.
So far, I'm just trying to figure out how high the
tension rises. That is, does the existing 200 pound
tension rise to 250 pounds, 300 pounds, 400 pounds,
or what?
This spoke question may be different from the classic
example of tension in a previously slack horizontal rope
after a weight is added, but I'm not sure whether the
pre-existing 200 pound tension matters.
If it's of any importance, the stainless steel spokes
are about 295 mm long, 2 mm thick, and stretch about
1 mm under 200 pounds of tension. My best estimate
of the angle of deflection under a 100 pound sideways
force is 4 to 5 degrees from the ends of the spoke to
the center.
Thanks,
Carl Fogel