Hey Everybody,

I have been out of this for a while and had a half-completed SCT that I plan on using for a basher. Before I order a few more missing pieces I just wanted to confirm my pinion gear and electronics choices. I will be running the Proline Badlands Tire
So I took the diameter of the tire and multiplied by 3.14
This got me 12.42

Next, I took my Spur Gear Teeth / Pinion Gear Teeth
Tekno SCT Spur: 44T
Pinion Gear: 15T(ALT 14T)
Total 2.93 (3.1428)

I got a total of 4 for my differentials (via this information: petitrc.com/Tech/UnderstandGearingRatio/]Understand Gearing Ratio)
So I multiplied 2.93*4 (ALT 3.14*4)
Final Drive Ratio: 11.7333333 (12.5712)

Lastly, I subtract the final drive ratio from the tire size.
15T = 0.68 (More Top End Speed)
14T = -0.15 (More Torque)

My plan is to run the SCT using a 3S lipo and HobbyWing Ezrun Max10 SCT and HobbyWing Ezrun 3652SL G2 (3200KV)

Does this all make sense? Or am I completely wrong?

Uuuhhh....🤔
Thats math right?

I admire the maths, but I’d build the car, and use the smaller pinion at first. Bring the car in after a few mins and check temperature. Repeat until the run is finished. If temps are ok, use then bigger pinion.

Don’t over think it, enjoy it : )

Exactly. Use a temp gun. Find a good conservative gear at first. Temps around 140 150 max.

Thanks all.

Just trying not to under gear it at the same time. With that current setup would you say start with a 13T and move up? I will have to place an order with Amain and I just don't want to add unnecessary items to the cart. I should be good with 13, 14, 15 and 16T?

Nothing wrong with the maths!!! Or using a temp sensor (and ultimately the math should be checked with a temp sensor!)


Your 44/15 is good and if your gear ratio of your diff is 4 (40/10) then your doing it right.

I usually only use the gearing as tire size usually stays the same. Even the 40/10 for the diff ring to pinion ratio of the differential inst a factor unless your tuning with that as well. Its more about the motor pinion to spur ratio then anything.


If you want to factor in tire size just take your gear ratio from above and divide it by the circumference. This is considered the cars rollout an is more important on on-road cars as they are sensitive to gearing changes and the foam tires when cut down changes the ultimate gear ratio.

https://www.rcuniverse.com/forum/rc-...o-rollout.html


So in your case the 12.42/11.73333 or 12.42/12.57

I'm running a sct410.3, with the max10sct and the 4600kv on 2s, with a 17t pinion. No racing, just a "basher". It runs awesome, more than fast enough, nothing overheats ever. Awesome truck. Your plan is what I wish I had done, but I had a bunch of good 2s battery so went with the 4600. Get a variety of pinion gears and test and tune till you and the truck are both happy.

​​​​​​​Awesome. Thanks. I've added a 13-16T pinion in my cart. Im sure those will be enough to get me where I need to be

Perfect. Thanks for the help!

4000kv on a 3 cell is to much battery..I and some might stay under 3500kv for 3 cell.12.6x 4000.. dont see this staying under temps with 3 cell..
just my 2 cents worth

thats my mistake. should be 3200KV