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Mower Building / Setup Help => Tires => Topic started by: TomC on November 05, 2005, 10:25:46 AM

Title: Rollout
Post by: TomC on November 05, 2005, 10:25:46 AM
*Rollout *
Post by Squidd on May 30, 2005, 4:40pm


In IMOW, we all run the same gear ratio (9:1) and the motors are
goverened (3650) ...

So it seems the only "advantage" in speed is going to come from rollout
or the circumfrence of the tire...

Now the rules states 18x9.5x8 is the maximum tire that can be run, but
not all tires (even with the same "size" ) are the same...

So, before I go out and buy 10 different tires blow them up and measure
their circumference...

Can anyone point me in the direction of the "Tallest" 18x9.5x8...or
18x8.5x8...??
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*Re: Rollout *
Post by Squidd on May 31, 2005, 6:58am


9:1 is 9 engine crank shaft revolutions to 1 axel revolution...

The one axle revolution (or "tire" revolution) determines how "far"
the maching moves..as all the machines are turning the same rpms the
the tire that goes "farthest" per rev will be "fastest"...

So a 17" tall tire will roll about 53.4" inches per rev... a 17.5"
tall tire will move almost 55"...at 405.5 revs per minute (3650/9)
the 17.5" tire will be 54' ahead or the smaller tire machine..

So...What's the "tallest" 18x9.5x8 tire out there...???

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*Re: Rollout *
Post by George Herrin on May 31, 2005, 8:34am


Trail and error. Kenda's are pretty consistant as far as bigger. Keep in
mind a tire inflation rule is coming. So over inflating will stop. Too
many tires explodeing.
George
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*Re: Rollout *
Post by Squidd on May 31, 2005, 7:44pm

Stopped at the local mower repair shop...Measured 8-10 different tires
mounted on a varity of rims (no Kendas though)...

And there is a difference...up to an inch and a half on different
brands/designs...

Have a pretty good idea where I'm going now, but will still need to
check the Kenda line to confirm...
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*Re: Rollout *
Post by Squidd on Jun 8, 2005, 7:56pm



*May 31, 2005, 8:34am George Herrin
Quote
Keep in mind a tire inflation rule is coming. So over inflating will
stop. Too many tires explodeing.



I see that's come to pass...

All the mower reason to find the "tallest" carcasses out there...
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*Re: Rollout *
Post by George Herrin on Jun 8, 2005, 9:41pm


Yes it has come to pass. I had thought it would have been sooner than
later but either way it makes things a bit safer. It will also make
things more equal on the track we are betting on too!!!!
George
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