From: shenry@cs.rice.edu (Sam Henry)
Newsgroups: rec.bicycles
Subject: Re: Mold Release & Preservative Agents (was Re: Road tires?)
Date: 13 Aug 92 22:34:01 GMT
Article-I.D.: rice.Bsy1Cq.7qn
Organization: Rice University, Houston

>Sam Henry writes:
>
>> Conti Grand Prix and SuperSports and SuperSport ULTRAs are very d*d
>> good tires.  I say that after doing product comparison testing first
>> hand--with the road rash and paint scrapes to prove it.

In article <9208122216.AA15320@hplomg.hpl.hp.com>
BRANDT_JOBST/HP1900_01@HPLOMG.HPL.HP.COM chides: 

>As if to give credit to my comment that riders give endorsements for
>tires without any comparative evidence, Sam goes on to furnish none of
>the evidence to which he alludes.  

Actually, the artilce was written before you chided anyone for not
citing evidenciary quantum physics and tomes of statistics.

>I get the impression that these statements are drawn from
>expectations that arise from exposure to promotional material.

Actually, I had never thought much about tires and knew not the
difference between this or that until I really started having problems
with the Specialized tires (the citation you excised).  I fell in love
with Contis after trying them based on a recommendation garnered here
when I asked for help.

I am now a convert, and heaven knows no zeal like a convert.  Call me
the St. Paul of the Road.

>For years I rode on Specialized Touring II tires and found that
>cornering on the raised center ridge caused disconcerting sounds but I
>cannot say that they did or did not corner as well as other tires.  

This is the tire I had the most problems with.  I could not keep them
stuck to the road.  I crashed on med- to high-speed downhill curves
that I had negotiated pretty much the same way under same road
conditions (moisture and surface) on different tires.  I crashed on
low speed turns that I did regularly on my daily commute.  

As one commentator remarked in discussing tires with me:  When they
(Specialized tires) let go, they let go.  That was my experience,
BAM--I was on the ground--no skid, no slide, nothing.

>I know only that they wore out about twice as fast as the Avocet ROAD
>20's that I use now. 

That was the second brand I had had recommended to me, the third was
Michelin.  The Michelins I disgarded because of their reputation for
cutting easily.  I tried the Contis because they were easier to get
than the Avocets.  So much for the rush of promotional material.

>Anyway, measurements have shown that cornering for the leading smooth
>tires is indistinguishably close, 

I have no tire tester, such as you and Avocet have conspired to
contrive.

>so I am not sure what the basis for tire preference is.  I am curious
>what the quantifiable differences are that Sam and other riders
>observe and on which their preferences are based. 

I have only my on-bike stability, durabiltity, and performance tests
to go by.  

BRANDS COMPARED (not many different ones, but sufficient mileage to
evaluate; I am not a research lab funded by Contitnental, Avocet, or
anybody else):

Continental:  

Super Sports: The current set has 2,500 kms.  The rear is finally
beginning to show wear--skid marks incurred during the daily commute.
Very stable in wet conditions (we get a lot of those in the tropics),
both damp and heavy rain.  I have not done as much intermediate
touring as usual this year (infants have short loiter times on bikes),
but I have done one 150 mile ride to Austin.  Included hairy roads
through river bottoms with fast descents and tight turns and cattle
guards.  Survived one emergency stop on a downhill curve without a
waver.   One flat--a snake bite caused by rider inattention leading to
not unloading to cross the grand canyon of pot holes.

Very true in corners and turns.
Predicted mileage:  at least 8,000 kms.

ULTRA:  The current set has 4,000 kms.  Almost time to rotate.
These are the tires that replaced the Spec Tour IIs.  The day that I
replaced them, I took them on a long ride looking for conditions under
which to test them.  At 32 kph, I was forced to leave a concrete
surface, traverse wet grass, and return to the concrete surface.  No
traction loss what so ever (though I did not have a traction loss
measuring device with me to gather statistics).  At 25 kph, I crossed
a railroad bed and a car kept me from hitting at the desired 90 degs.
I felth the back wheel slide and catch, but did not lose any control.
A few days later, on my commute, I was crowded into a gutter and
experienced an incident that I posted here some months ago asking for
an evaluation of whether or not I had reacted in the best manner.  The
point is, the tires as much as any bike handling skills were judged to
have contributed to my extrication with nary a scratch.
This past spring, I took these tires on several climbs and descents
(including the one where the Spec Tour IIs had failed) and had the
confidence to really push the limits of any cornering I had done
before--no crashes.  I dare say I might have even pushed the limits of
your famous 45 deg cornering.  One flat--a snake bite caused by the
rider--my wife [hee, hee]--paying more attention to the speedometer
while trying to set a land speed record and not unloading until after
crossing a heaved seam in the pavement.

Very true in corners and turns.
Predicted mileage:  at least 8,000 kms.

Schwinn Passage
Hwang Chung

These are a pair of cheap junk.  Low mileage (3-6 mos), not durable
(easily ruptured and cut, turn brittle at the slightest excuse).
Neither my wife nor I ever felt comfortable on descents with either of
these tires.  Now that my wife is on ULTRAs, she is only slightly less
of a descender than I--but then I am heavier and have less sense.

Specialized Tour II

I have posted the story of these tires a number of times.  Maybe I was
overconfident, but some of the low-speed crashes I directly attribute
to these tires.  Even the Schwinns and HCs had better traction.  
I reiterate: I will never, ever ride on Specialized tires again.
I can't speak to their mileage--I took them off long before they had
many miles or much wear on them.

>jobst_brandt@hplabs.hp.com

Not much statistical data there, but this is as close a I can come
to what the "differences are that Sam and other riders observe and on
which their preferences are based".  And I still have not read a
promotional piece published by Continental.  Or Michelin.  Or Avocet.
Or Specialized.  I did go by the evaluations and observations of folks
here and folks I ride with in getting to the Continentals.  I suppose
if I had been as easily able to get Avocets as the Contis, I would
have tried those, based on comments by you and others.  

Ooops! Did I just blow a chance to get a Conti endorsement deal?  Or a
sponsorship?  


-- 
sam henry <shenry@rice.edu>
Wanna ride?