Motorcycle tire rule change

[JackB750]

Just a couple of random thoughts/observations on this issue - 1). There have been questions about DOT Road Race Tires. These tires are specified/designed/manufactured/marketed as "racing tires " (see http://dunlopracing.com/) but are absolutely NOT marked on the sidewalls with "For Competition Use Only, Not For Highway Use" They are legitimately legal for highway use in the US and meet all the appropriate federal standards. As such they have the appropriate DOT labeling and numbers. 2). The DOT spec racing tires, as well as the "real" racing slicks are generally available in several compounds and constructions - some of which are specifically listed as "not for use at Daytona" where sustained speeds and vertical loads are high (sound familiar?) What mechanism exists to keep those tires off of our bikes since the sizes are the same and the sidewall markings give no indication? 3).  If the real intent of this rule was to protect against "issues" on bikes running at the unprecedented speeds where there is no history to rely on, wouldn't it have been simpler (and way more easily managed by the officials) to simply require "Race tires" on bikes running the long course. There is a huge body of experiential data that says ZR tires are adequate/safe at the low 200+ speeds being run on the short course. Of course, if it is an "200 mph" insurance thing then this wouldn't solve the problem. Just things to think about.  

[Stainless1]

The only flaw in all this thinking is the only sit on bike to run 270+ on the salt ran on ZR tires with no chunking, no issues at all... witnessed by Tom Evans, in fact he commented that the tire still looked perfect.

[WildBro]

Just read the 5 pages.

There are race only tires out there to use, Phill C. had a set on his bike this pass Maxton race.  He had to get a buddy's racers number to be able to buy them.

I have been running the Pirelli 240/40ZR 18, I also log surface tire temp with a IR sensor to my Aim Pro dash. And go over every inch of the tire after each run, check tire pressure every run right before we remove the tire warmer.

The info I have collected over the last few years will not match the salt.(I have never logged there, so I am unable to make any educated responce)
Tire spin means surface heat, sustained tire spin do to poor set-up/control will let the heat build up to the core.  Core gets too hot for to long, tire comes apart. In the mile, the tire will wear out before it chunks, on salt it will chunk. (food for thought: we are not drag racing, swingarm angle is important)  Taking a tire temp after a run with a temp gun means almost nothing.

If you want to think out side the box.... Sandy will make you a rim you can put a car tire on. www.kosman.net
But for most, just go with a bike race tire.  I am sure there will be a list of OK tires here in the near future. Looking for the cheap, after knowing the tire you want, get a race take off from Ebay.

Bill

[wobblywalrus]

It appears, based on information in these six pages, that neither race tires or street tires are guaranteed to work well on a these big monster bikes.  Some street tires might be OK, and also some race tires.  This shows that the tires can be made.

Purpose built tires are needed, or tire ratings on the sidewalls of existing tires, that show the rider that they are safe.  Perhaps "SCTA/BNI approved for 200 + mph?"   

[fredvance]

DW, as one of those lucky enough to have a record over 200, I was not contacted or consulted about the new rule. I have also beeb in touch with several others and to the best of my knowledge they were not contacted.

  Fred

[WildBro]

Was talking to Ryan on the phone and I found my tire from bonneville 2007.  It was used on our all motor Vmax, didn't go super fast (had some 198s)
Tire is a:
Pirelli Dragon Slick
190/55 R17
says "NOT FOR HIGHWAY SERVICE"
not sure if its still made
bought it off Ebay as a race take off, don't think the guy had the bike up straight, only had sidewall use.

Hope this helps,
Bill

[WildBro]

oh ya, tire rubber was SC1

Bill

[sheribuchta]

11 bikes at el mirage may meet were running on  200 mph record                            willie buchta

[desotoman]

Is there anyway you could use a car tire on a motorcycle? If so it would seem like this would solve the problem. Just thinking out loud.

Tom G.

[desotoman]

Double post.

[John Noonan]

I have run a flat profile car tire 218+ however it was on the sidecar, I don't want to run a flat profile tire on a bike as the bike gets sideways during the run and go's from the left side of the track to the right and then back a few times.  The GPS plot showed we went 1.35 miles to make the 242 mph run and when we plotted it in a straight line it was 1.3 miles.

It looks like making the run over a longer distance gave us a bit more mph. 

[desotoman]

John,

Thanks for the reply. I know you cannot use a flat tire, but the 28" Goodyear front runners I run on the back of my roadster are not flat at 50 PSI. They do have some curve on the tread area. I don't know if it is enough for a bike or not, but it would allow some lean with the same contact patch as vertical.

Tom G.

[John Noonan]

Tom,

The ideal situation would be if there were LSR tires that were compliant for SCTA/BNI rules and that the tires were to fit on existing 17" diameter front and rear wheels as that is 99 % of the faster guys and gal are using.

As I mentioned to a person yesterday on the when questioned about the smoothness of the LSR tires not getting traction I reminded them that all of the fastest cars are running them.  It will be interesting to see how they work on an open wheeled bike with regards to handling and traction/bite.


J

[jl222]

The only flaw in all this thinking is the only sit on bike to run 270+ on the salt ran on ZR tires with no chunking, no issues at all... witnessed by Tom Evans, in fact he commented that the tire still looked perfect.

  Are bike race tires tested to 270 mph? Are the failures from overheating from spinning and if so will race tires still fail?

       JL222

[Larry C]

Ed Maybry figured this out over twenty years ago. He put car racing tires on his triple triumph bikes and John Minnano went over 250mph.  As far as I know the bikes did not have any sideways or handling issues. I know this does not solve the problem of fitting tires on production motorcycle frames but it has been done and worked well.