Rlaarlo HongYan HY6 6x6 Brushed RTR

A brushed motor carries current through carbon brushes that rub on the commutator.

• It is cheaper and smooth at low speed.
• The brushes wear and the motor loses power over time.

Ready to run: built at the factory with the electronics installed.

• Some come without a battery or charger; the maker's box contents say which.

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.
• This one is 800 mm long.

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.

• On this car one tooth changes the gearing by about 7.1%.
• A bigger pinion loads the motor and ESC harder, so check the maker's gearing chart and feel the motor temperature after a run.

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.

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.
• This is the high range, which sets top speed and is what the calculators load first.

The same chain in low range: the transmission's second, lower set of gears.

• The pinion and spur are shared, so a pinion swap changes both ranges by the same share.
• This one is worked out from the low-range final drive the maker publishes.

Spur teeth divided by pinion teeth: the part of the gearing that a pinion or spur swap changes.

• Here it is 2.786:1.

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.

• This is the high range, which sets top speed and is what the calculators load first.

The final drive in low range, where a crawler spends most of its time: slower and stronger, for climbs and fine control.

• It is 2.0 times the high range.
• Switch the calculators to Low to work in this range.

This vehicle has a two-speed transmission: a high range for speed and a low range for crawling.

• The maker does not say how the range is changed.
• Both ranges share the pinion and spur.

The outside diameter of the mounted tire, tread to tread. A taller tire covers more ground each turn, which gears the car taller.

• At high speed tires can balloon and grow, so the real gearing gets taller as the car goes faster.

How far the car moves for one turn of the motor: tire circumference divided by final drive.

• It lets you compare gearing across different tire sizes; more rollout is taller gearing.
• Here it is 21.7 mm.
• This is the high range, which sets top speed and is what the calculators load first.

How far the truck moves for one turn of the motor in low range.

• Here it is 10.8 mm.

Brushed motors are rated by can size and turns rather than KV, so there is no KV to show.

The highest LiPo cell count the maker rates the electronics for. Each cell is 3.7 V nominal and 4.2 V fully charged.

• 3S is 11.1 V nominal and 12.6 V off the charger.
• Running more cells than this risks the ESC and motor.
• Many cars also run on fewer cells, only slower.

The motor fitted at the factory, as the maker names it.

• In a name like 5280, the digits usually give the can size: 52 mm across and 80 mm long. A bigger can makes more torque and sheds heat better.
• Brushed motors are often named by can size, such as 540 or 550, and by turns: fewer turns is faster.

The electronic speed control. It feeds power from the battery to the motor as you work the throttle, and usually powers the receiver and servo too.

• An amp figure in its name is normally the maker's continuous rating.
• A brushed ESC cannot run a brushless motor.
• Set its low-voltage cutoff for LiPo, so a pack is not run flat.

The plug on the battery lead. Your battery needs the same plug.

• An adapter works, but it adds resistance and another joint that can work loose.
• XT plugs are sold on packs from many makers.

A brushed motor has no KV rating, so no theoretical top speed is worked out. Compare gearing by rollout instead.

The vehicle's weight as the maker states it.

• The maker does not say whether it includes a battery.
• More weight takes more power to accelerate and lands harder on the parts; it changes top speed very little.

Overall length as the maker states it, usually with the body fitted.

• Useful for comparing real size, since scale labels are loose.

Overall width as the maker states it, usually with the body fitted.

• A wider car is more stable in corners and harder to roll over.

Overall height as the maker states it, usually with the body fitted.

• Useful when checking it fits a shelf, a bag or a car trunk.