# help... roll out!!!!



## parma24 (Apr 10, 2003)

hey what is roll out

how do u find out roll out

what is the gearing of 2.50 roll out and that is the gearing of 2.35 roll out

mark


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## fredracer (Nov 21, 2001)

roll out is the distance travelled with one motor rev

RO=tire diam x Pi / gear ratio


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## hankster (Jan 1, 1998)

We have a rollout chart available at http://www.hobbytalk.com/modules.php?op=modload&name=News&file=article&sid=23

We also have a "Gear Finder" program at http://www.hobbytalk.com/modules.php?op=modload&name=Downloads&file=index&req=viewdownload&cid=1


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## Guest (Feb 25, 2004)

For transmission cars you need to know it's ratio for direct drive you use only tire diameter divided by gear ratio (spur/pinion).
The difference you stated for example if tire and spur size were unchanged then the 2.50 is a larger pinion, while the 2.35 uses a smaller pinion.
Transmissions vehicles
transmission ratio multiplies by tire diameter (distance across x Pi 3.14) divided by gear ratio (spur/pinion) = rollout
Direct drive pan cars 
tire diameter (distance across x pi or 3.14) divided by gear ratio


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## Donn (Jul 25, 2002)

Hankster, neither of your links for a gear chart or roll out work, they just take you to the front page for the forums.


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## RPM (Dec 20, 2004)

parma24 said:


> hey what is roll out
> 
> how do u find out roll out
> 
> ...



WHAT??
You don't need charts or graphs?? You need math!  

** Note: this formula is for pan car 1/12 or 1/10 scale cars with no trans..

ROLLOUT FORMULA:

Rollout = tire size (inches) X 3.142 X Pinion size / Spur size


To find pinion size at a certain rollout the Formula is this:

Pinion = Rollout X Spur size / Tire size (inches) X 3.142

Just rotate the formula to what you need...and keep it smiple! :thumbsup:


___________________________________
No, I just stayed at a Holiday Inn Express last night!


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## Jim Smith (Oct 1, 2001)

Hey, charts and graphs can be ~fun~... Here's some to look at http://jimsmith.iwarp.com/RCDownLoads.html


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