John
I believe the reason for shaving tires is to reduce the weight and therefore
the effects that centrifugal force would have on the tire at high speed
(RPM).
And half tread should work just fine.
Rolling resistance is a whole other matter, but it can't be that much. My
timeslips from Maxton and Bonneville would indicate that altitude, and
slipery salt, are bigger factors than rolling resistance.
John Beckett, LSR #79
----- Original Message -----
From: "john robinson" <john@engr.wisc.edu>
To: <land-speed@autox.team.net>
Sent: Wednesday, January 26, 2000 9:09 AM
Subject: concerning tires
> Howdy,
> A few of questions and observations:
> I'm running "H" rated street radials on my H/CC at the Salt, they have an
> aggressive tread design, and one of the safety techs said that I should
> shave the tread for better speed. Somewhere I read that the coefficient of
> friction of the Salt is on the order of cold wet asphalt, and my feelings
> were (when I purchased the tires) that the aggressive tread would help in
> traction. my speeds are 130-150, (150 hope full, anyway) Any thoughts
here?
> Also, I've been reading Forbes Aird 's book "Aerodynamics" published by
> HPBooks1997, he has a very good section on tires and rolling resistance at
> the Salt, and it states in a passage relating to the Summers Brothers
> Goldenrod that the tires soaked up 61% of the total drag at the record
> speed, although the tire model used in the equation was based on 60 year
> old data... are there any newer equations available? anybody know how to
> test rolling resistance? or where I can get the info to do a rolling
> resistance test?
> Another book I just picked up and although it is directed at and about the
> solar vehicles built at various universities, is "The Leading Edge" by
> Goro Tamai, published by Robert Bentley1999. This book is focused on low
> speed aerodynamics and many of the concepts can be transferred to LSR.
> Although it does have advanced math in it, with the limited algebra I
> studied in high school, (well OK attended class and worried about pimples,
> girls and cars) I am able to follow most of it....probably because I read
> the Aird book first, easily understood math in it.
> Two years or so ago, Motion Software (the Desktop Dyno people) were
> developing a game/engine test software about Bonneville. It seems to have
> been in development, and then it died, anybody heard of it? got any
insight
> about why the program went away? they don't seem to answer their email,
> although they are still in business. I'd like to get my hands on it, just
> to play with it.
> anybody got any other reading material they'd like to share?
> anyway, that's about it for now, drive careful
>
> John Robinson, Mechanician
> Mechanical Engineering University of Wisconsin
> 1513 University Ave.
> Madison, Wi. 53706
> 608-262-3606
> FAX 608-265-2316
> Current World Land Speed Record Holder
> Bonneville Salt Flats
> H/GCC 92 cu.in. 1980 Dodge Colt
> 131.333 MPH set 1995
> 136.666 MPH set 1996
>
>
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