# pinion and spure sizing.



## 43forever (Nov 10, 2011)

i have an associated rc10l and a hyperdrive that i am trying to set up the same for me and my son to run in the parking lots. they will have the same motor and speed controller and battery combo. the motor is a novak 13.5 brushless. so what would be a good starting size pinion and spur gears for mid rang speeds and good run times.


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## 43forever (Nov 10, 2011)

ok so today i orderd 48 pitch pinion and spure. 27 tooth pinion and i think a 78 tooth spure for both cars . these should move them out pretty good across the parking lots.


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## swingerguy340 (Jul 17, 2007)

I haven't researched the power of brushed Vs brushless but the pinion/spur ratio you got is 2.88:1 and that's how I judge how good the car/truck is gonna go- it's gonna FLY with the 13.5t motor and that ratio-

IMO you should pick a ratio (pinion and spur) based off the weight of the car- I have a 2wd Traxxas Slash with a 20t pinion and a 90t spur (4.5:1) because it's a massive truck

the other cars I have are Tamiya TT01's are 15t brushed motors with the stock 19/61 (3.21:1) it's around 8.XX:1 final and I'm leaving that ratio because it's a heavy setup with NiMH batteries so it needs the torque to move it and not over heat the stock Tamiya ESC

basically if the vehicle is heavier you should pick a ratio a little lower (numerically higher) to make it a bit easier on the motor/ESC visa-versa if the car/truck is lighter choose a ratio a little higher (numerically lower)

also are you running NiMH or Lipo batteries? <-this alone makes a difference


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## 43forever (Nov 10, 2011)

thanks swinger guy . i will be running lipo batts. i am sure i will be accumulating a lot of pinion and spur gears to experiment with. yea it sounds like i picked some good highway gears there haha. i guess i will need a big parking lot haha.


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## swingerguy340 (Jul 17, 2007)

43forever said:


> thanks swinger guy . i will be running lipo batts. i am sure i will be accumulating a lot of pinion and spur gears to experiment with. yea it sounds like i picked some good highway gears there haha.* i guess i will need a big parking lot haha.*


yes you will haha


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## 4ThePinkRacing (Apr 30, 2010)

gear by temp .... also

novaks high temp limit is around 170 i think .. 

safe area 130s at least for me .... some run 150s but heat is stress on motor ..


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## 43forever (Nov 10, 2011)

i was thinking of getting a 20t pinion that . that would get me closer to the 4.0 ratio that ta man suggested for a starting point.do brushless motors run cooler then brushed. i can barrow a temp gun from work.


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## ta_man (Apr 10, 2005)

43forever said:


> i was thinking of getting a 20t pinion that . that would get me closer to the 4.0 ratio that ta man suggested for a starting point.do brushless motors run cooler then brushed. i can barrow a temp gun from work.


That 4.0 was with a 17.5. You should use a higher gear ratio (smaller pinion) with a 13.5.


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## 43forever (Nov 10, 2011)

ok so maybe a 4.5 or 5.0 ratio for the 13.5 motor


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## 43forever (Nov 10, 2011)

so about 18t pinion might be a good starting point with my 78t spure with the 13.5 brushless with lipo`s . so which compound tires are going to give me the most traction on asphalt.


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## gmackhurry (Jan 4, 2012)

43forever said:


> so about 18t pinion might be a good starting point with my 78t spure with the 13.5 brushless with lipo`s . so which compound tires are going to give me the most traction on asphalt.


Soft compounds = better traction but the shortest life span. 
Harder compounds = less traction but last a long time.
For asphalt and low running suspensions I like soft compounds with the clutch adjusted loose as to not spin the tires. It's not made for it but my favorite asphalt tire on a 2wd low riding sct is a bald Proline M3 Suburb. It can definately hold it's own.


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## 43forever (Nov 10, 2011)

yeah i understand the softer are more traction . so now i need to find a chart to tell me the color code from soft to hard. the tires on the hyper have a yellow strip around the tire. i think they are like spec tires or something. any way they seem way to hard/ slippery on the asphalt.


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## 43forever (Nov 10, 2011)

ok so some of my stuff came in from tower. i put the 48 pitch spure on the rc10l and it was scrubbing at the bottom of the rear end. so i put the spacer from the left side to the right and i looks fine but the left side now needs a spacer probably 1/8 inch. the duratrax 48 pitch spure was a good bit thicker then the 64 pitch that was on there. is that normal or should i look for thinner gears.tower wouldnt send me a return shipping lable for the pinions i want to swap so i am stuck with them but will buy some others from somewhere else. also what size motor screws do i need for this novak 13.5 brushless motor.


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## Bob~H (Jan 21, 2009)

The motor screws are 3mm, make sure they aren't too long, you will know as they bottom out in the motor before getting tight on the mount. Here is a guide to BSR tire compounds: http://www.johnsbsrracing.com/foam/10thscale.html . Have fun!


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## 43forever (Nov 10, 2011)

thanks bob. i wonder if the home improvement stores would have that small of a size or i have to order from a hobby dealer.


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## Bob~H (Jan 21, 2009)

Not really sure if home improvement stores would have them or not, could also be at a large hardware store.


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## 43forever (Nov 10, 2011)

also while installing the spure gear on the rc10l i noticed there wasn`t any thrust washers/bearing on the axle as shown in the assembly instructions. are these really needed or should i not worry about it.


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## 43forever (Nov 10, 2011)

well i stopped by low`s today and found some 3mm x10 slot head screws that works with w washer and a lock washer. the smallest socket head screw was a 4mm so these will work until i get the motor mounting screws from tower. but when i mounted the motor it is so big that it will only slide half way back along the screw slots. i just hope the 16t and 19t pinion gear that i just ordered has enough room to fit.


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