Landracing Forum
Tech Information => Technical Discussion => Topic started by: hawkwind on September 04, 2004, 06:18:00 AM
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G'day I've been following all the threads re motorcycle tires, very informative , but most of the information with a few exceptions ,is lacking very important data, BRAND/MAKE of tire, or is that on purpose ( secret info ) if not could members make public what brands they have used ,stating whether they were good ,bad or neutral , shaved or unshaved , pressures used and speeds that the tire attained
I have only used Michelin HPX unshaved , 50psi 203 mph no problems at all
Gary
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Gary, thanks for bringing up the bottom line on tires at speed: What's safe to use/what's not/ what's working/what's not . . . In 1999, Suzuki, having done the heavy lifting, brought out a bike that essentally offered a buyer 200 mph out of the box, the "theoretical" limit of ZR rated tires. With tuning for speed, turbocharging, nitrous, etc., the open wheeled bikes which use motorcycle tires are marching toward some pretty big numbers. The weak link is tires. When bikes outrun the capabilities of available tires, shaved or not, maybe future LSR runs will be on computer models. Too bad.
Perhaps someone will wander around the pits at Maxton, Goliad, and Bonneville, write down what people are using successfully and safely, or what didn't work, then post the findings. It's only proprietary info until someone reads the side of a tire.
I'm still looking for a way to develop M/C tires for LSR through a non-profit "in the interest of safety" foundation, but it's slow going . . . .
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<small>[ September 08, 2004, 06:24 PM: Message edited by: joea ]</small>
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200 out of box ///no on speedo...188 or so
real world
200 theoretical limit???//hell no
I went 244.449 average for mile, over 240
for over 2 miles, on a well used dunlop
D205 touring tire, I pulled it out of a used
tire pile out back of local dealership, it had
been sitting in my garage for nearly 3 yrs.......
the previous tire was a dunlop original sportmax
(unnumbered version came out in 88)
zr does not mean rated to 200, this zr has
a v280 designation on side, rated by dunlop to 173mph, we had many runs on it over 220
you can develop tires if ya like, I like using what already works, some very keen engineer types agree that zr tires may be good closer to 300mph, its all application specific, on salt
for what lsr does, many zr tires have worked
flawlessly
my tires were meticulously inspected after all
my runs this year, cleaned, measured etc
they literally look brand new
avon is helping another racer on salt,
they spec'd zr tires for his 240+ aspirations
another manufacturer, recommended against
gp tires, and recommended stock type zr
tires that come on busa
Joe :)
<small>[ September 08, 2004, 06:23 PM: Message edited by: joea ]</small>
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Thanks Joe for your input mate ,at least someone is willing to assist us slow un's,and k.h. your input is excellent I hope that you can get some manufacturer willing and interested in producing LSR tyres (tires lol) if I can assist in any way let me know
gary ( hawkwind racing )
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I got real interested in this subject a coouple of days ago when we shredded a Rennsport on the dyno. with a modified Gix 1K
A year ago I did twenty passes or so during two events on the OE Bridgestone BT012R F, it, and the front held up fine for speeds to 182 I ran 50 PSI
After destroying the Renn. I called the Bridgestone tech. he advised me that Bridgestone did not make a tire for Bonneville, but his recommendation was the OE tire. Thats what I'll be running next event.
Thats my limited experience. Its all still pretty new to me.
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Sizes for Motorcycles. Can't get the spec sheet to load at Kwaker.com, this a.m., but doesn't your Gixxer 1K take a 190 70 17 on the rear? We could use a poll of sizes people want to fit the greatest number of 200 to 300 mph bikes.
My preference for 200x50x17 Rear and 120x70x17 Front has been voiced to the representative of the tire company that will soon tell us if they can do LSR. Also told him that was just my choice and the greatest demand to meet a Return on Investment for them may be something else. And I'll be glad to adapt to whatever gets made. It is unlikely this specialty tire company will make a lot of motorcycle sizes right away, due to tooling costs, unless someone wants to step up with $15-20K for a specific need. So, for bikes, it may be "one size fits all" for awhile.
It appears ZR tires will meet the needs of bikes in the 200+ mph range. Therefore I ask motorcyle riders to vote, express their opinion, ask other racers, whatever, and form a concensus on what Front and Rear set of tires sizes, rated to 300 mph, will fit the requirements of the most machines. Thanks in advance.
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I've looked at some of the failed motor cycle tires at Bonneville. Things to think about:
Tires run on a chassie dyno, appear to be most likely to fail. Tires that the tread groves run clear acrosse the tire are high on the failer list.
Starting to see tires fail at less that 200mph,why? Spining the the tire through the mile? By not slowly increasing the speed?
Things that appear to work; Shaving the tires. Using a worn tire.
Why new tires fail; Heat build up at speed? The tread is pulling losse from the casing, because of the RPM and weight?
The SCTA MOTORCYCLE TECH CREW has been recording info on tires at each event, on each cycle that runs over 200mph or has a failer and new brands of tires.
Also seeing more Front Runner Car tires on cycles.
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like anything else, its very relative
Jon Minonno has some support from
Avon, they specifically spec'd a
hard compound ZR radial for Bonneville
type speed pursuits, many runs near
230, unshaved, many dyno runs on them
they look like new after every Bonn. pass
I ran a Dunlop touring tire, unshaved,
used, over 230 around 6 times at speedweek
twice over 240 mph, looked like new
after every pass
Noonan, ran 256, 253 average through the mile
averaged over 250 for around 3 continuous miles
and many 240 plus runs, all at same meet, on same unshaved
ZR radial, reports are it looks fantastic
so tires that may work perfectly at over 240
may be ruined at 180 with the right abuse
just like pistons, rods, spark plugs.........
Joe :)