Newsgroups: rec.bicycles.racing

Roger Marquis writes:

> I think this shows that you have not been putting in the miles of
> late.  I know few (racing) cyclists who share your opinion Jobst.
> When was the last time you did a 300mi week, much less the 600mi
> weeks the pros do, in all sorts of weather, in competition, all
> year long.

This reminds me of an argument some biker started about bicycle
wheels.  He based his "facts" on how many more wheels he had built
than I and that "who should know better" what's going on in spoke
failure.  I don't think Greg Lemond knows more about tire selection
than technical people who make scientific investigations.  I think
Shimano has shown Campagnolo that the analytic process can get
results not otherwise easily achieved.

>  Like I said, if you're just putting around ...  Anyone putting in
>  serious miles knows there are big differences between tires, both
>  clinchers and sew-ups.  Descending with National Team riders and
>  ex-Professionals you learn these things.

I don't believe that name drops and fame by association has any
value in debating technical differences.  However, just to give your
contention some perspective, Lemond, who is often mentioned as a
better than average descender rode locally with some of the guys to
the coast going up Kings Mountain and down Tunitas Creek Rd.  After
waiting at the top for the "slow" hosts, he promptly was off the
back after the first turn.  It isn't like he doesn't know these
roads either because he won some races on them.  Great bike racers
are not necessarily fast descenders.  The guys I know in Switzerland
use the classic excuse by calling my speeds crazy... a madman.  You
know, of course that everyone who is slower than you is a dork and
anyone faster is crazy.  Have you ever heard anyone speak otherwise
of riders who go faster.

Besides, I take this as a ploy.  You know very well how much and how
far I ride just on my summer vacation both by my postings and from
my nephew with whom you ride now and then.  I do not have to get
into a pissing match here on who rides farther.

About tubular glue melting on descents:

> This is definitely true when it's over 95 degrees out, otherwise it
> is not a factor and certainly not a 'main difference'.

I have made measurements of this and know that aluminum rims get
over 110 deg C descending in cold weather.  The European classics
regularly descend these roads and are aware of these problems.  From
your contention one might believe the heat generation was from
ambient air.  The only reason the temperature doesn't go higher is
that only so much energy is available to a single rider.  Tandems
can melt brake pads and explode tires... even in cold weather.

About tubular glue giving rise to rolling resistance:

> You're not serious are you?  Did you pick this one up in the
> national Enquirer Jobst?  I can see the headlines "Sew-Up glue
> found to absorb energy, professional teams migrating to clinchers
> en-mass".  You found this in one of those British magazines right

I don't know what British magazines you mean.  I certainly didn't
get it out of any US magazines either.  I got these from tests
performed at the Japanese tire testing laboratories where clinchers
and tubulars were tested.  The rolling resistance data has been made
public and shows that tubulars, except for their constant glue
losses, roll better than most clinchers.  The glue losses are
constant and offset tubular performance curves so that they come in
about the level of a Specialized Touring II.  As I mentioned, track
(hardening) glue is the only one that gives the full benefit of
these tires.  After years of wondering what the real meaning of
track glue was, I was dismayed that this could not be found in any
racing book.

jobst_brandt@hplabs.hp.com
From: jbrandt@hplred.HPL.HP.COM (Jobst Brandt)
Date: Fri, 8 Jan 1993 18:07:36 GMT
Subject: Re: Team Motorola will Race on Clinchers in 1993
Organization: Hewlett-Packard Laboratories, Palo Alto, CA