[CR]Re: Leave the mill at home (was Urban Legends)

(Example: Framebuilding:Restoration)

From: "Stephen Barner" <steve@sburl.com>
To: <classicrendezvous@bikelist.org>
References: <CATFOODLAX3cf3ednHM00002fec@catfood.nt.phred.org>
Date: Mon, 18 Aug 2003 23:25:52 -0400
Subject: [CR]Re: Leave the mill at home (was Urban Legends)

And the point to this experiment would be--besides the incredible fun you can have playing around with a Bridgeport on a lousy day--that tied and soldered wheels behave no differently than regular wheels, when they have a milling machine attached to them. I imagine it makes it tough to get up hills. I know I had to use the bucket loader on my tractor to get my Bridgeport in the basement shop.

This vignette is a great example of how you can very precisely measure attributes that may not accurately reflect what happens to the component in service. Precision =/= accuracy.

Steve Barner, Bolton, Vermont


----- Original Message -----


> Date: Mon, 18 Aug 2003 12:21:17 -0500

\r?\n> From: Todd Kuzma <tullio@theramp.net>

\r?\n> To: Joe Bender-Zanoni <joebz@optonline.net>,

\r?\n> <Classicrendezvous@bikelist.org>

\r?\n> Subject: Re: [CR]Urban Legends, by Jobst Brandt

\r?\n>

\r?\n> I don't have my copy of "The Bicycle Wheel" here to check for quotes from

\r?\n> that, but here is what he has to say about tied and soldered wheels in the

\r?\n> rec.bicycles.tech FAQ:

\r?\n>

\r?\n> ----

\r?\n>

\r?\n> While writing "the Bicycle Wheel", to conclusively determine what

\r?\n> effect tying and soldering of spoke crossings in a wheel had, I asked

\r?\n> Wheelsmith to loan me an untied pair of standard 36 spoke rear wheels,

\r?\n> on on Campagnolo low and high flange hubs. I had an inner body of a

\r?\n> freewheel machined with flats so that a wheel could be clamped into

\r?\n> the vise of a Bridgeport milling machine while the left end of its

\r?\n> axle was held in the quill.

\r?\n>

\r?\n> With the hub rigidly secured, with its axle vertical, dial gauges were

\r?\n> mounted at four equally spaced locations on the machine bed to measure

\r?\n> rim deflections as a 35lb weight was sequentially hung on the wheel at

\r?\n> these positions. The deflections were recorded for each location and

\r?\n> averaged for each wheel before and after tying and soldering spokes.

\r?\n>

\r?\n> The wheels were also measured for torsional rigidity in the same

\r?\n> fixture, by a wire anchored in the valve hole and wrapped around the

\r?\n> rim so that a 35 lb force could be applied tangential to the rim.

\r?\n> Dial gauges located at two places 90 degrees apart in the quadrant

\r?\n> away from the applied load were used to measure relative rotation

\r?\n> between the wheel and hub.

\r?\n>

\r?\n> Upon repeating the measurements after tying and soldering the spokes,

\r?\n> no perceptible change, other than random measurement noise of a few

\r?\n> thousandths of an inch, was detected. The spokes were tied and

\r?\n> soldered by Wheelsmith who did this as a regular service. The data

\r?\n> was collected by an engineer who did not know what I expected to find.

\r?\n> I set up the experiment and delivered the wheels.

\r?\n>

\r?\n> ----

\r?\n>

\r?\n> Todd Kuzma

\r?\n> Heron Bicycles

\r?\n> LaSalle, IL

\r?\n> http://www.heronbicycles.com/