Re: Nobody knows about RR
- From: carlfogel@xxxxxxxxxxx
- Date: Thu, 28 Jul 2005 19:32:43 -0600
On Thu, 28 Jul 2005 23:17:25 GMT,
jobst.brandt@xxxxxxxxxxxxxxxxxx wrote:
>Neil Brooks writes:
>
>>>> I thought that makers of bicycle tires would have experimentally or
>>>> scientifically based knowledge as a foundation of their
>>>> production.
>
>> I jumped in late and, unfortunately, haven't caught this thread in
>> its entirety, so forgive me if this has already been posted.
>
>> Interesting article:
>
>> Adobe document p.8
>> Magazine p.14
>
> http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf
>
>> Along with its testing and conclusions, it makes reference to the
>> following sources (which I haven't attempted to locate) of RR test
>> data:
>
>> Cycling Plus, issue 62 (Feb. ?97) ?Winter tyres?; Cycling Plus, issue
>> 68 (Mid-summer ?97) ?Road tyres?; Cycling Plus, issue 81 (Aug ?98)
>> ?Time-trial tyres?; Total Bike, issue 6 (Oct ?97) ?MTB tyres?; and
>> BHPC Newsletter, issue 58, ?MTB tyres?.
>
>The section on rolling resistance (pp 14) has a disconcerting flavor
>to it in two ways. First the author attempts to establish credibility
>through his years as an engineer and long association with recumbents.
>Then the test method is explained showing that no direct measurements
>of drag were used but rather the derivation of drag by differentiation
>of rolling speed.
>
>http://www.terrymorse.com/bike/imgs/rolres.gif
>
>Printing a table of myriad numbers may be a good archive but such data
>is better displayed in curves and preferably curves made of more than
>one data point. What we have in the IHPVA report is none of that. In
>fact the information shown in the RR graphs above of decades ago is not
>visible in these data.
>
>> The article, "On the Efficiency of Bicycle Chain Drives" is
>> particularly interesting as well.
>
>I don't see anything interesting in that piece because the
>measurements are not normalized to be comparable. Behind all this
>testing is the simple concept that chain efficiency depends on
>articulation angle for one cycle under load, nothing less. What
>conclusions are we to draw from these measurements and to what good can
>they be used?
>
>I see this a s a major snow-job that obscures the essence to what the
>test titles allude.
>
>Jobst Brandt
Dear Jobst,
Gosh, I never expected you to disparage anyone writing about
the technical side of bicycling!
Do you know of anyone whose work is vastly superior in every
respect to everyone else and is aslo much more interesting?
Hopefully,
Carl Fogel
.
- References:
- Re: Nobody knows about RR
- From: Neil Brooks
- Re: Nobody knows about RR
- From: jobst . brandt
- Re: Nobody knows about RR
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