Alan who? writes:
>> You don't need to detect windup if you don't have any, but the spoke machine people, both Holland
>> Mechanics and BMD, don't want to talk about it.
> Isn't that the truth? Why fix it if it's not broken. Maybe in the end, the extra effort is just
> not worth it. If the wheels these machines are targetted at a market that don't expect the wheels
> to last 10,000 miles, then why build them to that spec? How about the Mavic Kysriums and other
> pre-built wheels? Are they machine built? How do they stress relieve and deal with spoke windup?
> Some of these wheels use bladed spokes, surely that must be a nightmare.
Wheels of all price ranges should be machine built, if not today, some time in the future when
someone realizes there is a large unmet market. The bicycle business is not a fast learner as you
see especially in wheels. Just consider that until the printing of "the Bicycle Wheel" the cause for
spoke and rim failure was not known, nor was the concept that the spokes of wheels standing on the
shelf have more stress in them than in a wheel being ridden. This stuff has been hanging around for
more than 100 years and no one in the bicycle business bothered to study the prestressed wheel and
why it is such an elegant structure.
>> By a radial pneumatic piston pressing on the rim to unload the spoke being adjusted gets rid of
>> thread torque along with spoke twist.
> Won't you still need to have a method of holding the spoke? Even if the threads are greased, there
> must still be a measurable amount of friction between the nipple and the threads. I know when
> building my own wheels that no matter what I do, I still get spoke windup even if I do the
> prescribed method of turning and backing off the nipple. I would really need something to hold the
> spoke in place.
If you can thread a spoke nipple onto a flat spoke by hand, then the machine can do it just as
easily by unloading the spoke at the moment of adjustment. These machines have myriad are pistons
and control sensors anyway, so it's not a significant addition although it is a significant
improvement of throughput and precision and enables high tension to be achieved.
>> As for stress relieving, there are two problems, the obvious one is to relieve peak stresses in
>> spokes but the other is to improve the spoke line so that 'outbound' spokes lie against the
>> flange on their way to the rim.
That's no problem. There are two machines, one is used to lace the wheel and bring it to 90% of
final tension and the aligner robot that does final tensioning and truing. Spoke line problems are
easily addressed in the lacer and stress relieving and tension in the aligner. You'll notice that
Holland Mechanics as well as BMD calls stress relieving "stabilizing" because they do not understand
the concept... and therefore cannot talk about it with mere people who don't use their product.
> That's the other thing I notice when building some of my wheels is that in order for me to have
> the 'outbound' spoke lie against the flange of the hub, I would have to put quite a 'bow' in
> the spoke.
I think there is something wrong here. Improving the spoke line is something done after the wheel is
laced and moderately tight. I don't understand your "quite a 'bow'" comment. Are you sure we are
talking about the same thing?
> I bend the spoke one by one so that initially they lie against the flange but as I tighten up the
> wheel, they naturally straighten out and don't necessarily stay flat against the flange and I try
> to improve the spoke line as I tighten the wheel. I don't have any problems with my wheels but
> that's not to say they're perfect.
What can I say? You seem to be unique in this experience. Either that or you are doing something
entirely different. The second seems to be the case judging from your earlier comments.
Jobst Brandt <
[email protected]> Palo Alto CA
