Motorcycle tire rule change

[landracing]

  And let me make this perfectly clear,no 'approved' NHS roadracing tire is going to survive on a 700hp/550lbs turbo 'Busa moving at 270+mph on either a short or long course.

How about a Kawasaki?

[landracing]

Think outside the box - or tire -

JA

Or the wallet

Is there a price on safety?

[sockjohn]

Think outside the box

IMHO, the unintended consequences of that could be worse.

[RIFLEMAN]

Think outside the box - or tire -

JA

Or the wallet

Is there a price on safety?

There is a price on everything. Especially when you're running on a shoestring budget and can't get straight answers.
  Jon,you've been doing this forever. Honestly,you've run the big numbers,do you feel unsafe with the high end DOT legal ZR W suffix tires up to 225? I only have to make it to 206 and I feel safe. Has anybody hit the UK sites and seen what they have been running and how their tires have been holding up? They have been running 230-240 for some time now.

[firemanjim]

Great, another darn all cow rule!!    
Roadracing tires are not designed for what we want, too soft of compounds and too thin of carcasses. Really suited for pavement--no traction for salt/dirt, and on much lighter,lower HP bikes.They toss these tires after one  race--or less. So Please be good enough to give a list of recommended tires if you are going to implement such a far reaching blanket ruling. Or see lots of fast bikes head to Bubs.
And this is the first I have heard of it as well.

[dw230]

Rifleman,

If you will notice the quotes I put around that statment it means it is not of my opinion but, copied from someone else. As I mentioned before I was/am not a part of the research, discussion or decision to impletment the rule chnage. Are you a member of the advisory committee or hold one of the 29 records over 200 MPH? If so I would have thought that you were called upon for an opinion.

Please see the contact info in the original thread post for further info.

DW

[dw230]

BTW,

Has anyone contacted Scott Guthrie or Bill Warner for info on the tires they are using to run 270 MPH at Maxon?

DW

[landracing]

No one said racing is cheap. Racing costs money. If you have the love of the sport, then you will come through for what you need.

It doesn't really matter our opinion if we feel safe or not. Our opinion is just that our opinion with no real engineering data to back it up. Yes we have run tires fast. Maybe we were lucky.

The failure of the tires seems to follow a pattern. The tire failures have occurred probably 95% or higher on Busa powered machines. This tells me, in my opinion, that what is happening is tire spin. With no data to back up my claim I can only offer my opinion and visual perceptions. Haybusas are hitting an aero wall and are trying to power their way thru this barrier instead of finding better ways to manage traction or improve the aero and thus spinning the tire, or riders are just trying to put to much power to the ground and spinning the tire to failure.  Heat is a big issue. How long it is ran is another.

I ran into one rider that was putting only 12-15 psi in his tire.

How many tire failures have been on the short course? I can't recall any.

I'm sure bonneville racers have been running speeds faster then the UK bikers for some time. Im afraid their data of how fast can not apply to us, and nor does it matter in reality.

Ill leave what the experts have to say and go with their ruling.

Do we need to have a death before something is going to be done? Most rules have come about due to a severe penalty paid by one of our fellow racers, why not take the cautious approach and call this preventive maintenance before a catastrophic event occurs.

[bak189]

Rifleman, OK. I will try to behave myself......but it really upsets me when it is well known by some
"chosen" racers what this ruling is all about......and we get no answers.  Right, at the present time it does not effect MY team.  But it does effect a certain sidecar streamliner of a very good friend of mine who had plan to race both SCTA/BNI and the BUB.  Rifleman, you noted in your last post that you understand the reason for this rule change.....really, would you please tell me the reason......certainly
not safety....(unless of course you are able to get special LSR tires... but that appears to be a secret)
Right, at the present time my team does not race at any of the SCTA/BNI events, we only race the BUB since 2003 (however, am still a 32 year member of BNI) Among one of the many reasons we now race the BUB is due to the fact that in my 30 plus years of BNI membership they will drop a rule change on you at any given time. Example of just a couple in my class: Sidecars;  1987 no passengers in the chair, (no input from the sidecar racers)  1991 do away with the SC-A class (no input)  1991 Your streamliner sidecar that you ran last year is no longer safe for 1992.  Solo's that we raced  2001 regarding the fairing on our
125c.c. bike legal in 2001, bring it to Tech 2002 "your fairing is not legal, we must have missed it last year" .  Todate, we have not had any of these problems at the BUB Meet..... Using roadrace tires is going to hurt someone badly.  

[RIFLEMAN]

 Am I being censored? I have posted 4 replies and they ain't coming up Hope its a server problem.
Goodnight all,no hard feelings and I hope this works itself out. Would really hate to give it up or move to a slower class.
Peace

[osti]

BTW,

Has anyone contacted Scott Guthrie or Bill Warner for info on the tires they are using to run 270 MPH at Maxon?

DW

Bill runs ZR rated Pirelli street tires and a giant 240 rear tire at that. Has from the begining as far as I know.

[osti]

No one said racing is cheap. Racing costs money. If you have the love of the sport, then you will come through for what you need.

It doesn't really matter our opinion if we feel safe or not. Our opinion is just that our opinion with no real engineering data to back it up. Yes we have run tires fast. Maybe we were lucky.

The failure of the tires seems to follow a pattern. The tire failures have occurred probably 95% or higher on TURBO Busa powered machines. This tells me, in my opinion, that what is happening is tire spin. With no data to back up my claim I can only offer my opinion and visual perceptions. Haybusas are hitting an aero wall and are trying to power their way thru this barrier instead of finding better ways to manage traction or improve the aero and thus spinning the tire, or riders are just trying to put to much power to the ground and spinning the tire to failure.  Heat is a big issue. How long it is ran is another.

I ran into one rider that was putting only 12-15 psi in his tire.

How many tire failures have been on the short course? I can't recall any.

I'm sure bonneville racers have been running speeds faster then the UK bikers for some time. Im afraid their data of how fast can not apply to us, and nor does it matter in reality.

Ill leave what the experts have to say and go with their ruling.

Do we need to have a death before something is going to be done? Most rules have come about due to a severe penalty paid by one of our fellow racers, why not take the cautious approach and call this preventive maintenance before a catastrophic event occurs.

I think you forgot one key word in there. I added it. Why not limit the special tires to the blown classes? Any tire failures on the naturally aspirated busa's?

[cranberryroo]

Why are the drag slicks not allowed on the salt? Is it because they are slicks? Drag racing tires seem to be the only other race tires besides the road race ones. What about drag radials that have some tread? I haven't seen this much confusion in a while!

[RIFLEMAN]

Why are the drag slicks not allowed on the salt? Is it because they are slicks? Drag racing tires seem to be the only other race tires besides the road race ones. What about drag radials that have some tread? I haven't seen this much confusion in a while!

Drag slicks are too soft and designed to only be abused for 1/4th of a mile.

[stay`tee]

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This is evedience of what can happen if you run too soft of a compound tyre ,,, it is a Metzler Racetec 190/55 ZR,,,

At the DLRA Speedweek 2006 at Lake Gairdner the course was very wet and slippery ,,,

This is the result  after a timed 204mph pass,, held the revs at 11000 through the three mile timed section,,, which, with the gearing i had was 224mph, so there was approx 10% slippage,,, the Gods were on my side that day ,,