How tall is my tire~?~ Taller than yours I say~!!~

[outlawbusa]

But only at certain speeds, and even then I may be lying~!~

I have heard that tires grow over an inch at high speeds...which makes me wonder, hhmmm

What tires grow the best (or worst depending on how you look at it), and what compounds~?~

I have developed my own opinion on this but don't want yours to be biased, besides...my opinion on it defies any form of logic so it might change in the future~!~

My fastest speeds have been run on tires that I think would grow the least, but maybe it's more that it keeps the bike in it's prime RPM/HP range without growing more, sending me to a a false conclusion~!!~

 

[Commuta_Busa]

Tire temp, pressure, air, nitrogen, or other dry gas used to inflate them, tire brand, compound, speed, load all factor in the amount of tire growth I've seen. I'm sure carcase and sidewall design/media play a big roll. I had soft Perilli's filled with air that grew like mad on me.

 

[dadofthree]

How would you recognize this growth ? It goes without saying that the hotter a tire gets the higher the pressure inside that tire gets and the larger the tire will get because of this increase. I just don't know about an inch. If you watch top fuel drags you will notice a huge change in profile, but those tires are designed to do that. I don't think you'll see street tires changing like that.

 

[outlawbusa]

Other than the occasional rubbing inside the fender, what are the dangers of growing too much~?~

Tires these days seem to hang on for dear life with todays technology and don't seem to have much of a problem, but has anyone ever seen a tire grow to the point of unseating the bead or causing other discrepencies in our normal way of thinking a tire should act~?~

What got me thinking about this ... I heard stories about the front tire coming down from wheelies and deforming so much that it breaks the bead...rumor is they showed it on the high speed cams of time warp...

I'd like to see how the tire reacts at 200+

 

[outlawbusa]

I don't think you'll see street tires changing like that.

I don't know how to accurately measure the growth, but I can see evidence of it...

It'll rub below the radiator (when lowered) and also on the inside of the front fender.

Come to think of it, this may be why Brock ran a shorter than stock front tire (if I remember correctly)...

 

[Draco1340]

At loring this summer I mounted a .062 delrin dowel off the swingarm is such a way that it would grind down to length on the wheel as the wheel grew. I was interested in % slip, and needed to know exactly what the tire diameter was. By measuring clearance before and after run, I could measure tire growth. Long story short, my Dunlop grew less than 3/16 or an inch at 40 PSI.

 

[outlawbusa]

How would you recognize this growth ?

Ok, here is evidence that a tire grows on a Busa at speed~!~

It rubbed through my plastic...did on Kevin's bike also...

I'll have to measure the "sitting still" clearance once it's all back together

 

[Commuta_Busa]

what about when you're hard on the brakes? Have you compressed the front end to see how much clearance there is?

 

[outlawbusa]

Bet that would be a great factor in this also~!~

 

[Commuta_Busa]

wrap a ratchet strap around the top yoke and through your wheel. Ratchet it down until you bottom out the front. Another way is with a wheel chock. Ratchet down the front end and compress the front suspension until it bottoms.

 

[Got-Busa?]

How are you lowering the front and how low do you have it...?

 

[outlawbusa]

How are you lowering the front and how low do you have it...?

I'm going to find out soon, I bet you all are right and the tire may be close when lowered (and suspension compressed)...can't lower for a couple more weeks due to parts taken off right now (usually ride at stock height) but I'll take a close look and measure once it's lowered...I think Ken's idea about the compression is going to play a big part in this also because if I remember correctly it looks like it has plenty of room while just sitting there.

 

[Commuta_Busa]

a buddy of mine went a hair to low and when he went hard on the brakes the front fender hit the bottom yoke and caused a nice shimmy in the bars. I told him he was to low but he didn't think he bottomed out the forks while hard braking. Well, almost bottoming them out, if you know what I mean.

 

[carlsbadbusa]

Dunlop Ntechs slicks grow...ALOT....so im not doubting this might be the case

 

[outlawbusa]

How about pulling back a thread from ancient times~?~

Here's a recent shot showing evidence of tire growth. My fender and Kevin's fender both looked about the same once removed.

This would not be a result from suspension travel since the fender is stationary...

 

[dadofthree]

Have you measured the clearance with the tire cold ?

 

[dadofthree]

I need to check my front fender. Are you guys running LSR events ? Just curious how long you maintain those speeds.

 

[dadofthree]

May have missed it. What tires are you guys running ?

 

[outlawbusa]

Yes, these are from LSR events...1 mile runs mostly (Kevin ran Boneville last year also but used a shaved tire).

I have a set of harder compound Battleaxes to burn off on the straight line tracks (cause I really really hate these tires on their sides) stock size front

Kevin runs soft compound race takeoffs and does it too, stock size front

 

[dadofthree]

I wonder if the front fender Tiger Racing developed gives additional room ?