Author Topic: Car Tire on a bike ( video )  (Read 22772 times)

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Offline wrongway

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Re: Car Tire on a bike ( video )
« Reply #60 on: July 23, 2009, 12:41:24 PM »
your statement...."I think I have demonstrated the the car tire is capable of maintaining control in situations more extreme than is seen at the land speed events with the videos"............

is interesting...........

your obviously speaking from your experience............

which in the land speed world is...?????????????????//

records...???speeds.....???    the only response to your speeds
has been...."very fast"..........define very fast............

I don't think i have ever said very fast. My car is faster than my bike :-)

I did set a naked record in MF/1650 at 189 year before last.
Quote
...........situations more extreme than seen at land speed events.........really...??????

when the rear wheel is spinning.....say when coefficient of friction is exceeded......
and the rear wheel begins oscillating....ie sliding left and or right......what do you
think the edge of the tire does or will do............that video would be enlightening.......

I don't think I have ever seen that on pavement ... I do record some  wheel spin at maxton , but much less with the car tire. I cant imagine ever running this on the salt.

Roy


Offline narider

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Re: Car Tire on a bike ( video )
« Reply #61 on: July 23, 2009, 12:50:16 PM »
While you may believe that there maybe a potential for  not being able to control the bike , I dont think there are any facts support that.

You're right Roy, and that's one of the reason we have not banned it from being ran yet.

You originally asked me about running this tire last year sometime. I told you there was no specific rule in the book keeping you from it (barring the president, race director, chief tech or chief starter saying no). So I said lets see how you and the rest of the organization feel about it if you're set on running it, just make sure to have a standard motorcycle tire mounted on hand in case we deem it unfit for use for whatever reason.
I commend you for bringing it to light here, although I think your "data" thus far is more harmful then helpful to your cause, and we will continue to discuss and and try to make a final decision on it.

Also remember your reasoning of running it was that you were spinning your tire in 6th gear and needed better traction, I will say again that your bike didn't have enough power to spin a decent motorcycle tire. And I also said that there are many MC tires that will stick much better then that car tire at Maxton due to the course surface and layout, as well as me believing you can go much faster without it for the fact of additional weight early in the run and additional drag at the important end.

At the speeds you've obtained there's no major concern for issues so far as long as your runs are fairly uneventful. Best case scenario is you go continue to go averagely fast for the type of bike you're riding, but worse case scenario is what we're worried about.

Discussion will continue to take place both publicly here and privately with the organization and I will keep you in the loop if something changes of course... thanks again for bringing this issue back to lighta nd do keep that back up tire handy for any reason you may want to decide to use it.
Todd
« Last Edit: July 23, 2009, 12:57:02 PM by narider »

Offline wrongway

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Re: Car Tire on a bike ( video )
« Reply #62 on: July 23, 2009, 02:43:28 PM »
I agree with everything said  except that at +9" over , the bike tire will spin.

Roy

Offline Warp12

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Re: Car Tire on a bike ( video )
« Reply #63 on: July 23, 2009, 04:28:09 PM »
I agree with everything said  except that at +9" over , the bike tire will spin.

Roy

Your bike is 9" over?

Offline petercalaguiro

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Re: Car Tire on a bike ( video )
« Reply #64 on: July 23, 2009, 04:31:20 PM »
Regardess of all opinions, you gotta admit that Roy is always thinking.....and he usually goes pretty damn fast........ sometimes the hard way!
Keep it up, Roy, and continue to go fast! 
Peter
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Offline wrongway

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Re: Car Tire on a bike ( video )
« Reply #65 on: July 23, 2009, 04:51:56 PM »
I agree with everything said  except that at +9" over , the bike tire will spin.

Roy

Your bike is 9" over?

sorry , 8"
I have the roaring toyz 2"-8" extensions.... I try to run it as far back as I can or as far back as I need to to stop the wheelies.

Roy



Offline relaxedfit

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Re: Car Tire on a bike ( video )
« Reply #66 on: July 23, 2009, 07:40:05 PM »
Black hole of knowledge here-- Is there a point at which contact patch begins to resist acceleration even if the bike still making power? Obviously, a car tire on my bike would just mean I could take the side stand off.
Ken Presson
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Offline wrongway

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Re: Car Tire on a bike ( video )
« Reply #67 on: July 23, 2009, 07:47:59 PM »
Black hole of knowledge here-- Is there a point at which contact patch begins to resist acceleration even if the bike still making power? Obviously, a car tire on my bike would just mean I could take the side stand off.

At the drag strip i saw less than a 2 mph change going from the stock setup to the heavier rim and car tire. At maxton I saw no difference in speed.

Roy

Offline Warp12

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Re: Car Tire on a bike ( video )
« Reply #68 on: July 23, 2009, 08:32:21 PM »

sorry , 8"
I have the roaring toyz 2"-8" extensions.... I try to run it as far back as I can or as far back as I need to to stop the wheelies.

Roy


At what hp level did wheelies begin to significantly impact your top speed? What was your bike configuration and highest speed achieved at the time you decided to add wheelbase?

Offline narider

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Re: Car Tire on a bike ( video )
« Reply #69 on: July 23, 2009, 09:09:51 PM »
Roy,

I went 207mph faired and Deb went 209mph faired (and 202mph naked) on less then 215hp with a bone stock wheelbase and we never had the front wheel off the ground on any of those runs. Not only has her bike always ran a standard 190/50-17 motorcycle tire, but it is a Bridgestone OEM STOCK MOTORCYCLE STREET TIRE.

One of Scott Guthries bikes with twice the hp of your bike (conservatively),  never broke the tire loose once on a pass that went over 250mph (again, a standard 190mm tire).

Some of the 250+mph runs on Rich Yancy's bike were done with the wheelbase SHORTER then stock!

I know the tires and the run history very well on Charlie's bike, enough to know you heard what you wanted to hear about it only being able to make 2 passes per tire.

What I'm getting at is that the rider is more important then the tire in the situations and justifications you are trying to explain. I think you are trying to put a bandaid on a papercut that wouldn't bleed if you just left it untouched and quit dragging paper across your hand.

Just a couple FYI's concerning wheelbase, wheelies, spinning and rider control.
Todd


« Last Edit: July 23, 2009, 09:11:36 PM by narider »

Offline sockjohn

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Re: Car Tire on a bike ( video )
« Reply #70 on: July 23, 2009, 09:15:10 PM »
Some of the 250+mph runs on Rich Yancy's bike were done with the wheelbase SHORTER then stock!

What do you gain by going to a shorter wheelbase, or was this a byproduct of another change for some other reason?

Offline sockjohn

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Re: Car Tire on a bike ( video )
« Reply #71 on: July 23, 2009, 09:26:34 PM »
  I run a very small very low powered bike . The 250cc four stroke. I have thought of using a front tire from a motorcycle on the rear to reduce drag . As it is I run the max recommended tire pressure to get the tire on a point . judging from the dirt on the tire I ride on about three inches of rubber. It looks to me like Roy has a lot more rubber on the ground . BUT he is going twice as fast .

Is the concern hear that the bike will loose control or the tire will fail?

Just out of curiosity, what tires are you running?  I would think you would be hard pressed to find a narrower tire than the 125 GP slicks




Offline Warp12

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Re: Car Tire on a bike ( video )
« Reply #72 on: July 23, 2009, 09:33:40 PM »
Roy,

I went 207mph faired and Deb went 209mph faired (and 202mph naked) on less then 215hp with a bone stock wheelbase and we never had the front wheel off the ground on any of those runs. Not only has her bike always ran a standard 190/50-17 motorcycle tire, but it is a Bridgestone OEM STOCK MOTORCYCLE STREET TIRE.


I have had similar results to Todd and Deb. Riding Racheal's Turbo, I went 207 and Racheal went 211 mph. The bike is stock wheelbase with a regular old 180/55 Dunlop Qualifier. As for hp, well, enough to go 211 mph.  :-D  No wheelie's to speak of.

Shane

Offline John Noonan

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Re: Car Tire on a bike ( video )
« Reply #73 on: July 23, 2009, 11:36:54 PM »
Some of the 250+mph runs on Rich Yancy's bike were done with the wheelbase SHORTER then stock!

What do you gain by going to a shorter wheelbase, or was this a by product of another change for some other reason?

Shorter bike means more weight over the driven (rear) tire.

Better traction..just not for the thread starter, his bike has too much power and needs a sport touring compound car tire for his much slower bike with about 1/3rd the hp of much faster bikes on the same track.


J

Offline JimL

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Re: Car Tire on a bike ( video )
« Reply #74 on: July 24, 2009, 02:02:57 AM »
Just curious....read a little article recently about tire size changes when vehicle weight doesn't change.  It basically said that at normal pressures, the contact patch for wider tires doesn't get bigger (to any significant amount) because the patch gets shorter as it gets wider.  The explanation said that the vehicle weight (pounds per square inch) actually stays the same if the pressures are similar.

I found it interesting, because in my younger years we learned to run VERY skinny tires (and a little taller) on our 4x4s in the winter snow (grew up in Colorado).  We didn't get stuck near as much, and the cars would run much straighter on slippery surfaces.

Wouldn't the contact patch be more dependant on tire pressure, than tire width (assuming there's some curvature in the tread)?

I'm curious to hear what works best for tire pressures (mc tires, on the salt)....I never gave it a lot of thought, to tell the truth, just ran them pretty hard.

Regards, JimL