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Need help to get a 47 rollout.

Need help to get a 47 rollout.

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Old 02-13-2009, 07:30 PM
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Default Need help to get a 47 rollout.

Im building a F103rm and was told to achieve a 47 rollout. When I plug the info into the rollout calculater the pinion spur combo doesnt seem right. Can anyone give me advise where I should start. I wanna run 64pitch, I currently have 64p pinions ranging from 18-22 so I would prefer to just buy a spur instead of pinions. Any help would be great.

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Old 02-13-2009, 07:34 PM
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what is the formula for rollout?
what kind of track do you race on? oval?
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Old 02-13-2009, 07:37 PM
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your going to need to know the tire size to calculate a rollout....
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Old 02-13-2009, 08:05 PM
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Originally Posted by rccar306109 View Post
what is the formula for rollout?
what kind of track do you race on? oval?
I used this calc http://www.rcuniverse.com/community/gearwizard.cfm

Indoor carpet.

Originally Posted by joey View Post
your going to need to know the tire size to calculate a rollout....
According to Towers spec, brand new rear tires for the F103rm are 60mm. And i am pretty sure i read somewhere 3.7 ratio. But the calc asked for tranny ratio, i assume its the same thing.

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Old 02-13-2009, 08:42 PM
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Thumbs up RE....Rollout

Try gearchart.com....The 103 is direct drive isn't it?????
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Old 02-13-2009, 08:52 PM
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yes go to gearchart .com and you can find what you want i was just there and if you have a 96 spur and a 24 tooth pinion you will get a 47.12 roll out and yes where it says pic a car you need to pick 10th /12th scale which they call pan car because your trans is 1.1 good luck and have fun you can just put your spur and the rest of your numbers in and go from there and dont forget as your tires get smaller you will half to recalculate your rollout
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Old 02-14-2009, 03:03 AM
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Porty,

80 spur 20 pinion will get you 47.1 rollout on a 60mm tire. For a direct drive car like yours, the tranny ratio is 1.0 or 1:1

To calculate rollout, use this formula:

(tire diameter * 3.14) * (pinion / spur) = rollout

for the number above,

(60mm * 3.14) * (20 / 80) = rollout, or

(188.4) * (.25) = rollout, or

47.1 = rollout.

Another handy formula is this one:

(spur/(tire diameter*3.14)) * rollout = pinion

Use that one when you know the rollout you want, and need to find the pinion to use.
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Old 02-14-2009, 04:06 AM
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Seen as this is sort of a gearing topic. I have a problem with motor heat. My 540 motor is getting extremely hot. At the moment I have a 96 spur and 58 pinion in. Is that over geared?

Ratio is: 4.03

Originally I had 96 spur and 48 pinion but that made the motor get hot as well. Well any help is very much appreciated.
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Old 02-14-2009, 04:08 AM
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Originally Posted by THEBIGBULL View Post
Try gearchart.com....The 103 is direct drive isn't it?????
Thank you!!

Originally Posted by 2056dennis View Post
yes go to gearchart .com and you can find what you want i was just there and if you have a 96 spur and a 24 tooth pinion you will get a 47.12 roll out and yes where it says pic a car you need to pick 10th /12th scale which they call pan car because your trans is 1.1 good luck and have fun you can just put your spur and the rest of your numbers in and go from there and dont forget as your tires get smaller you will half to recalculate your rollout
Thank you!!

Originally Posted by Trips View Post
Porty,

80 spur 20 pinion will get you 47.1 rollout on a 60mm tire. For a direct drive car like yours, the tranny ratio is 1.0 or 1:1

To calculate rollout, use this formula:

(tire diameter * 3.14) * (pinion / spur) = rollout

for the number above,

(60mm * 3.14) * (20 / 80) = rollout, or

(188.4) * (.25) = rollout, or

47.1 = rollout.

Another handy formula is this one:

(spur/(tire diameter*3.14)) * rollout = pinion

Use that one when you know the rollout you want, and need to find the pinion to use.
Thank you!!

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