Team Corally SBX-425

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.

All four wheels are driven. That gives more grip under power, especially on loose ground.

• The cost is more parts to maintain.

Sold without a motor, so you choose the motor, ESC and battery yourself.

• Rows that depend on the motor say so.

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.

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.

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.

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.

• It depends on the motor you fit, so the maker does not list one.

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.

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.
• This one is worked out from the tooth counts the maker publishes.

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.

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.

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.
• This car runs thicker oil in the front diff (15K) than the rear (10K): steadier on turn-in, with a rear that lets the car rotate.

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.

What the shocks are and how they are built, as the maker describes them.

• Oil-filled shocks damp with silicone oil; friction shocks, found on some entry-level cars, damp with a sprung plunger and cannot be tuned with oil.

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.

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 (50 wt) than the rear (35 wt). The front reacts more slowly, which steadies the steering, while the rear follows the ground more freely for grip under power.

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.

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.

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.