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My old rc10 (with 6gear tranny) got a Reedy Radon 17t brushed motor for christmas running with an inexpensive hobbyking 45a brushed esc that has lipo cut off. i started running it with a 4000mah 2s lipo yesterday but the motor and esc seems to get a bit hot. Currently using the 81t 48p spur w a 17t piniion, should i go to a 16t pinion or get an 87t spur? There are other brand spurs i could probably fit with less than 87t, more than 81t, go there before 87t? im using the stock sized wheels and tires (jconcepts detonator version). will an 87t spur fit behind the stock rc10 dust cover? will a 16t or smaller pinion get close enough to work with the 81t spur?

i just want to cruise around in the grass basically. looking more for longer run times over high top speed.

I think you need to go down a few pinions. I'd start with a 14. My son's RC10T with monster truck size 2.2's has the same motor and I have it geared 87/18 (FDR is 10.875) and he can run a full 5000 mah 2s lipo without the motor getting too hot.

I'd try something in the FDR range of 10-11.

81/14=10.58
87/15=10.61

Running in grass is going to increase your motor temps as well.

thanks for the reply ca-rj.

On your son's truck with the 87t spur, does the dust cover fit without problems? I think im gonna get an 87t so have a bit more flexibility with pinion option in the future as the 17t pinion with the 81t spur seems to reach close to the end limit of the motor slot (maybe with the other hole on the motor can it may allow smaller pinions than i assume?)

Hi,

With a 6 gear I think you will run into problems with the gear cover running a bigger spur than 81th.

The new RPM gear cover max 81th with a 6 gear.

Don't run it in grass, it will get hot!

Cheers, Dave.

I am not running a cover on my son's truck. Mostly out of laziness.

I've got an 87t covered by the stock gear cover on my 6-gear right now. Part of the trick with gear covers is to drill the screw holes very carefully, so that the adjustment nut is in the exact center of the access hole, whether it is a stealth or a 6 gear. The top shafts are in different locations between the two, which is why you can get rubbing on some but not others.
OP, you're right that you will run out of options with the 81t, since the motor hits the trans case before you can tighten a 15t, but a 16t fits. I would just gear down until the temps are reasonable, since heat kills magnets and burns up brushes in a hurry. I run a 91t in my tekin mid with a 6 gear, but I had to cut the bottom off the cover to clear it. Tiny pinions don't last as long, and create more friction. I like the Kimbrough gears 'cause you can fill them with 18 balls; more balls is better!
If you're bashing with lipo, you may just need to pause in your run if the motor gets too hot. Darn that grass!

DaveM wrote:The new RPM gear cover max 81th with a 6 gear.

The new RPM cover goes over an 87 on a 6 gear with zero issues. Fits like a glove.

Hi Guys,

It's interesting about the New RPM Classic gear cover on a six gear with a 87th spur, one of my cars

it went straight on no rubbing, the next car it rubbed badly!

Work that out!

I have bought 81th spurs for my 3 six gear cars.

Cheers, Dave.

the 87t spur fits by the way. very close but no evidence of rubbing the dust cover.

Lemon, I gave the same car, motor, Novak T4 and 5000mah lipo to a friend for his daughter to run. I want to say it was geared 81/16, then bumped up to 81/18 running on the street. Even with my pro soldered motor leads, the 14 gauge wires became hot enough to desolder. You could not touch the motor for more than a second. I say run it until you let the smoke out

After only buying a re re worlds last year to run in a vintage festival we have down here, and being very happy with it, i know own a erdinger goldpan, graphite team car and a b2(well 3..one i got for 16.90!) anyway in one of the classes we have to run the goldpan as it was in the day, no mods, same tyres etc and a 27t mubachi brushed control motor...i though it was just me but after playing around with gearing a bit and even at 81/18 ( the standard setup for 27t) the motor still gets fairly hot after a 5 min run on the track...and its painfully slow...is this just the norm? Is there anything that can be done gearing wise to get it to run faster yet cooler? I started with 81/26..yes i know..was fairly zippy at the top end but u could fry eggs on the motor..81/24 was my fav for acceleration and reasonable top end but still waaaay to hot..any help would be appreciated...i would run a lower turn motor but cant in the classic class

I would ensure you have all fresh/good bearings and zero drag in the entire drivetrain. Outside of that, keep the motor clean and lubed up, run it.

Totally rebult it, gearbox runs smooth, new bearings in the rear hub carriers etc..