Top speed expands tires how much?

[stopintime]

I'm thinking about going to a 190/55 tire (5.75" rim) which obviously has a larger radius (5.5 mm).

How much larger does a tire radius become at top speed?  (my bike at 155 mph)

Theoretical clearance issues are with swingarm and DP hugger......

[ducpainter]

Don't do it. 

[stopintime]

Don't do it. 

Don't do what - top speed, larger tires, drink beer 

[ducpainter]

Don't do what - top speed, larger tires, drink beer 

Larger tire.

The bike doesn't need it.

[Raux]

ahhh but it may 

[stopintime]

ahhh but it may 

Be that as it may  , but I'm really just trying to choose the best tire for my riding.

The 5.75" rim is somewhere in the middle of typical 180 (5.5) and 190 (6.0) rims - I've been told it's down to personal preference.

I have no tire experience other than from stock to SportTec M3.
My riding requires a rounder tire than a 190/50, so I'm going to try a 190/55 if it isn't too large for swing arm clearance.
The position of the eccentric hub means a lot too - if my new 15/44 gearing puts the eccentric at 8 or 9 o' clock, I might be in trouble with a 190/55. There is also the hugger to consider.

From other sources I've been told that a 1098R race ream run any gearing/eccentric position that will maintain
a 5 mm tire/swingarm clearance.

[ducpainter]

ahhh but it may 

He can do what he wants...

but all a 190 tire on his 800 will do is slow down the handling

[Raux]

He can do what he wants...

but all a 190 tire on his 800 will do is slow down the handling

and after all the suspension work he did to increase the handling and stability... good point.

[stopintime]

With my mods and my size/weight I have few problems flicking my bike - if I'm active
I think I'm in a totally different position than a "stock" size rider, riding passively on a stock bike.

With that in mind, I'm not afraid of a "slower" tire. If I don't like it I can change back at the next tire change.
I can't not do my best to find out the differences....

My reasons for a change:
possibly better suited for the rim dimension
possibly a little more traction
cool factor

[ducpainter]

To answer your question, the only tires I was aware of growing appreciably were some of the older Dunlop race tires.

The newer ones were changed. They found the tire growing affected the handling in a bad way on race bikes.

[hackers2r]

Interesting.  What wheels are you running that are 5.75"?  My thoughts are that if you run a 180 on a wider than ideal rim, such as you are doing, you will get a flatter tire.  Am I wrong on this?  Because of this, if you wanted a rounded, more aggressive tire, I would think that you have to run a 190/55.  Maybe I'm wrong but that's my interpretation.

[ducpainter]

Interesting.  What wheels are you running that are 5.75"?  My thoughts are that if you run a 180 on a wider than ideal rim, such as you are doing, you will get a flatter tire.  Am I wrong on this?  Because of this, if you wanted a rounded, more aggressive tire, I would think that you have to run a 190/55.  Maybe I'm wrong but that's my interpretation.

I think you're right, but either tire will work on that rim.

[Speeddog]

~~~SNIP~~~

From other sources I've been told that a 1098R race ream run any gearing/eccentric position that will maintain
a 5 mm tire/swingarm clearance.

I was thinking 1/4" of growth would be about all you *might* see.

[stopintime]

I was thinking 1/4" of growth would be about all you *might* see.

You're close enough to deserve a beer  Nate - take care of that, will you?

Metzeler answered quickly, but not quite fully....

* Diameter at maximum speed 652 mm* (320 km/h)(190/55)

So, a little math follows...
   17" x 2.54      ............432 mm
+ 190 x 55% x 2  .........209 mm
=                               641 mm

If this is real world correct measurements for an inflated standstill tire,
then,
the "dynamic growth" is 5.5 mm (diameter 11 - radius 5.5)

Subtracting a couple of mm for my not-quite-320km/h top speed,
and,
adding the 5.5 mm from tire size change
= no problem (unless the eccentric hub is at ~8 o'clock - maybe not even then)

I'm still waiting for Metzeler to confirm that a 190/55 tire is actually 104.5 mm high when inflated and at a standstill.

Does this sound right to y'all y'all?

[atomic410]

for dunlops and other tire fitment to rims you should consult a tire professional.  the guy who works at a dealership or shop chances are is not a professional tire guy.  for dunlop contact sportbike tire services and for michelin i would contact sport bike track time and link to their michelin page.  heres a link to dunlop.

http://dunlopracing.com/

btw i would stick with a 180