Team Associated's RC10B84D Classic Kit is a four-wheel-drive 1/10 dirt buggy kit in a Classic livery, sold without motor, electronics, wheels or tires.
A 78T spur on the centre diff works through a 2.5:1 internal ratio, so the pinion you fit sets the final drive. The diffs are filled with 15K front and rear and 200K in the center, and the shocks with 35 wt and 30 wt. Change the center oil first if the buggy pushes or spins its rear under power.
The kind of vehicle the maker sells it as. It sets what the car is built to do and which cars it is fair to compare it with.
Buggies are low, light off-road cars built for jumps and fast corners on dirt, clay or turf tracks.
Drive
All four wheels are driven. That gives more grip under power, especially on loose ground.
The cost is more parts to maintain.
Power
Sold without a motor, so you choose the motor, ESC and battery yourself.
Rows that depend on the motor say so.
Build
A kit you build yourself from parts.
Most kits come without motor, ESC, servo, radio and battery, and many without tires or a painted body.
The manual lists what to add.
Scale
The maker's nominal size compared with a full-size vehicle. It works more as a class label than a measurement.
A 1/10 monster truck is far bigger than a 1/10 touring car, so compare length and weight for real size.
Part number
The maker's product number for this exact version.
A V2, a new color, or a kit instead of an RTR usually has a different number, and parts can differ between them.
Check it against your box or receipt before ordering parts.
Class
Buggy
Drive
4WD
Power
Motor not included
Build
Kit
Scale
1/10
Part number
90056
Drivetrain
Pinion
The small gear on the motor shaft. Fewer teeth gear the car shorter: quicker acceleration, lower top speed and a cooler motor. More teeth do the opposite.
On a chassis sold as kits, each kit brings its own.
Spur
The large gear the pinion drives. A bigger spur with the same pinion gears the car shorter.
Pinion and spur must have the same pitch, or tooth size, to mesh.
The Gearing parts table below shows this car's pitch and part numbers.
On this car the spur is mounted on the center differential.
Transmission & axle
Every reduction after the spur, multiplied together: transmission, differentials and axle gears.
It is fixed by the design; the gearing you change is the pinion and spur.
Final drive
How many times the motor turns for one turn of the wheels. A higher number is shorter gearing: more acceleration and pulling power, less top speed.
Diff oil, front
Silicone oil sealed inside the differential. A diff lets the wheels on one axle turn at different speeds in a corner; thicker oil makes it act more like a solid axle.
At the front, thicker oil keeps both front wheels pulling out of a corner but makes the car turn in less willingly; thinner oil steers more easily.
It is graded in cSt (centistokes), a measure of thickness that means the same across brands. K means thousands, so 15K is 15,000 cSt.
Diff oil, center
The center diff splits power between front and rear. Thicker oil there sends more drive to the end that has grip and helps acceleration; thinner oil lets the car steer more easily off the throttle.
Diff oil, rear
The rear diff mostly shapes drive out of corners.
Thicker oil there puts power down more evenly on loose or slippery ground; thinner oil lets the car rotate more easily through a corner.
Front and rear diffs run the same oil here (15K).
Pinion
Not applicable
Spur
78TStock
Stock
Transmission & axle
2.50:1Stock
Stock
Final drive
Not applicable
Diff oil, front
15KStock
Stock
Diff oil, center
200KStock
Stock
Diff oil, rear
15KStock
Stock
Wheels & tires
Tire diameter
The outside diameter of the mounted tire, tread to tread. A taller tire covers more ground each turn, which gears the car taller.
Race tires wear down over a day, and a smaller tire gears the car shorter.
Tire diameter
Not applicable
Suspension
Shock oil, front
The oil in the shocks slows how fast the suspension moves. Thicker oil settles the car more slowly and resists bottoming out; thinner oil lets the wheels follow bumps.
At the front it mostly shapes the steering: thicker oil makes the car turn in more calmly and dive less under braking; thinner oil turns in sharper and keeps the front tires on the ground over bumps.
Racers go thicker for big, smooth jumps and thinner for rough, choppy tracks.
It is graded in wt here. A wt number is the oil maker's own grade and differs between brands, so match the brand, or use the oil maker's chart to convert.
Shock oil, rear
The rear shocks mostly shape grip under power and how the car lands.
Thicker oil at the rear holds the back up on landings and keeps it steadier on the throttle; thinner oil lets it squat and follow rough or loose ground for more grip.
This car runs thicker oil at the front (35 wt) than the rear (30 wt). The front reacts more slowly, which steadies the steering, while the rear follows the ground more freely for grip under power.
Shock oil, front
35 wtStock
Stock
Shock oil, rear
30 wtStock
Stock
Power
Motor
Motor KV is the RPM a motor turns per volt with no load.
This vehicle comes without a motor, so there is no stock KV; it depends on the one you fit.
Motor shaft
The diameter of the motor's output shaft, which a pinion's bore must match.
This vehicle comes without a motor, so it depends on the one you fit.
Battery
The highest LiPo cell count the maker rates the electronics for.
This vehicle comes without electronics, so it depends on the ESC and motor you fit.
Motor
Not applicable
Motor shaft
Not applicable
Battery
Not applicable
Performance
Theoretical top speed
It needs a motor KV, and this vehicle comes without a motor. Fit one and the calculator works it out from the motor's KV and the gearing.
Theoretical top speed
Not applicable
How to read these figures
Stock is as the vehicle ships.
Calculated is worked from the stock figures on this page rather than stored beside them, so the two cannot drift apart.
Not applicable means the vehicle does not come with it, like the motor on a roller or the tires on a race kit, or does not have one, like a KV rating on a brushed motor.
Pinion and spur parts for the Team Associated RC10B84D Classic Kit: fitted, and optional gearing supplied in the box
Component
Teeth
Pitch
Bore
Part number
Fitted at the factory
Spur
78T
48P
Not applicable
92149
About teeth, pitch and bore
Tooth counts are the ones in the specifications above.
Pitch is given as metric module (Mod 1, Mod 0.8) or diametral pitch (32P, 48P). They are different standards and are not interchangeable, even where the numbers look close.
Bore is the pinion’s hole, listed separately from the motor shaft.