> wrote in message news:[email protected]
> David Ornee <[email protected]
> >> does the Wheelsmith approach truing a radially lumpy rim but laterally acceptable rim in a
> >> different manner than the inverse?
> > From their site at URL http://www.wheelsmith.com/page4.html
> > "Wheelsmith's wheelbuilding philosophy emphasizes strength and durability, and the key is high,
> > uniform spoke tension. Spoke tension is the most difficult and elusive aspect of wheelbuilding.
> > It is the characteristic of the wheel most difficult to evaluate, yet the most critical to its
> > performance. This approach to wheelbuilding, based on combining both art and science, and
> > focusing on tension rather than cosmetic trueness, was pioneered by Wheelsmith and remains at
> > the foundation of our process. Cosmetic trueness can actually come at the expense of a wheel's
> > strength because it can result in unbalanced tension. So do not be misled by some builders'
> > claims about trueness, because what really matters is not how true a wheel is now, but how true
> > it is 1,000 miles from now."
> > Tension is a very important element in wheel durability. I can speak for my experience and what
> > I have learned from reading more experienced and those that approach from an engineering base
> > ("the Bicycle Wheel" by Jobst Brandt). Most new rims will allow you to get high and even tension
> > while maintaining lateral and acceptable radial true. Most experienced wheel builders will
> > adjust for the best tension balance and lateral true, while using radial to make up for the
> > irregularities in the rim. The builder's tolerance for imperfections in radial true is usually
> > under 0.5 mm from "peak" to "valley".
> That's all nice to hear but there is a fly in the ointment. A wheel that is true and does not have
> uniform tension is a loose wheel. As most wheel builders know, when the spokes get up to proper
> tension, THEY determine how true the wheel is, not the rim, that otherwise covers for tension
> disparities. Wheels are often built too loosely to not disturb the original trueness of the rim.
> If the tensioned wheel is fairly true, yet does not have uniformly tensioned spokes, the spokes
> are too loose.
> Jobst Brandt [email protected]
Palo Alto CA
Very interesting! I have limited experience of only building 250 wheels and working on 360 that
others have built. I always try to follow the methods described in the Jobst Brandt book: "the
Bicycle Wheel". However, I have thrown out 5 or 6 rims because I was not able to get the spokes at
uniform high tension and have the wheel true. I thought it was the rim's fault. I assumed there was
some damage or weakness in the rim when I couldn't get uniform high tension and true at the same
time. I tension for minimum of 100 kgf on spokes of the front wheel. I have used 170 kgf on Mavic
D521 and T520 front spokes. Both these examples built very true and within 5% of tension balance.
David Ornee, Western Springs, IL