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Old 11-30-22, 01:00 PM
  #48  
mrrabbit 
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Location: San Jose, California
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Bikes: 2001 Tommasini Sintesi w/ Campagnolo Daytona 10 Speed

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Originally Posted by Yan
Exactly what part of my statement do you have a problem with? Two posts directed toward me and you haven't uttered a single word of actual information. Trash in trash out.

No offense but that Park TM-1 you use is an utter POS. How do I know? I have one. It's a cheap tool (cheaply made, yet not cheaply priced) that uses a simple spring to measure against a linear scale. A spring like this doesn't even supply a constant force as the spring sweeps through its range. The idea of having a scale stamped on a design like this is a farce in itself.

Ok, so you're calibrating it to a particular tension force and using it to hit one target, no scale involved. Good, but now comes the critical death sentence for this tool: the readings it gives isn't even consistent! Squeeze that thing five times and it will give you five different readings. Squeeze slowly, then next try squeezing quickly, different reading as well! Why? Because it uses a polymer slider in a metal channel. The static and dynamic friction of the slider makes any kind of repeatability impossible. Using this tool is like using a slinky as a ruler.

You want to build a wheel properly? Use the DT Swiss tensionmeter. It's $587. Or you can get one for $50 from AliExpress that is 100% identical. Probably made in the same factory just without the branding profit markup.
https://www.dtswiss.com/en/component...ng/tensiometer

I say again, exactly what part of my statement do you have a problem with? I'll be waiting for an answer that makes sense.
If you are the "experienced" guy as you claim to be...

Then the following IS TRUE:


1. YOU already know that we provide estimates for spoke by spoke tension and overall average tension. To do otherwise is a waste of time and pointless.

Dial indicators and Digital indicators exist to provided better resolution where precise measurements are needed.

For our purpose, they are a waste of money - just fancy paperweights.


2. YOU already know that the reliability of our tension meters is a function of their being kept calibrated.

The TM-1 can last anywhere from 100s to up to a 1000 wheels before the spring breaks. That spring is easily replaced.

Their physical reliability is NOT the issue.


3. YOU already know that not all spoke material grades are the same for the same gauge and not all treatments are the same.

This further drives the estimation factor measurement on top of the already easily recognized imbalances from imperfect rims and hubs.


4. YOU already know that the truest indicator of what the tension load is to the nth degree would be the spoke itself telling us:

"Hey! I feel a 107.3995 +/- .0001 kilogram load on me!"

But it's an inanimate object...so we do the best we can. We take an indirect reading with an imperfectly human constructed middleman that measures deflection with a followup interpretation.

It's called a tensionmeter. And it does the job we need it do.

The Park TM-1 included.


So either:

A. Your statement was that of a blowhard with something to sell delivered in a one-liner . . .

or

B. Your statement did reveal your ignorance and you have now been corrected.


=8-|
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Disclaimer:

1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:

Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
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