Element RC Enduro Knightrunner RTR

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.

• Crawlers are built for slow, controlled climbing over rocks: very low gearing, flexible suspension and locked axles.

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

• The cost is more parts to maintain.
• A crawler needs every wheel pulling to climb.

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.
• That low-speed smoothness is why so many crawlers use one.

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 462 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 5.6%.
• Crawlers run small pinions for slow, precise wheel speed on climbs; a bigger one is quicker on the trail but harder to control on rocks.

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.

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

• Here it is 4.833:1.

The type of each differential, as the maker states it.

• A gear or ball diff lets the wheels on one axle turn at different speeds in a corner; a spool or locked diff turns them together for straight-line drive and climbing, at the cost of steering.
• Crawlers often lock both axles so every tire pulls on a climb.

Hub bearing size: The documented drivetrain connection or size for this exact model. Match the mating component before buying a replacement.

The tooth spacing of the fitted gear, stated as metric module or diametral pitch.

• The meshing pinion and spur need matching pitch. A missing pitch can be inferred from the other fitted gear; module and diametral pitch are not silently converted.

The tooth spacing of the fitted gear, stated as metric module or diametral pitch.

• The meshing pinion and spur need matching pitch. A missing pitch can be inferred from the other fitted gear; module and diametral pitch are not silently converted.

Whether the front axle is driven by the motor.

• The calculator uses this axle's own tire size and complete recorded gear path.

Whether the rear axle is driven by the motor.

• The calculator uses this axle's own tire size and complete recorded gear path.

Every reduction after the spur, multiplied together: transmission, transfer case and axle gears.

• That chain is why a crawler's figure is much higher than other classes'.
• 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.

Every reduction after the spur, multiplied together: transmission, transfer case and axle gears.

• That chain is why a crawler's figure is much higher than other classes'.
• 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.

• Among 1/10 crawlers & trail trucks in the catalog, the middle half run between 30.4:1 and 49.8:1 on stock gearing; this one is 47.1:1.
• Crawlers run far higher ratios than other classes, so the truck can creep and hold on a climb.

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.

• Among 1/10 crawlers & trail trucks in the catalog, the middle half run between 30.4:1 and 49.8:1 on stock gearing; this one is 49.8:1, shorter than most.
• Crawlers run far higher ratios than other classes, so the truck can creep and hold on a climb.

How the driven axles are connected.

• The coupling has not been established from a source. It is not inferred from 4WD or from the axle differentials.

Front rollout divided by rear rollout, minus one, expressed as a percentage at equal axle-input RPM.

• The front tires cover 5.7% more distance than the rear at equal axle-input RPM, using the listed diameters and reductions. The connection between axle inputs is not recorded, so its ability to accommodate a mismatch is unknown. These figures do not predict vehicle road speed.
• Positive means the front covers more distance per input turn. Zero means matching rollout, rather than matching wheel RPM.

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

• Crawler wheels are named by rim size, such as 1.9 or 2.2 inches; that is the wheel, not this tire diameter.

The hex on the axle that the wheel locks onto and is driven by. A wheel must match the hex size to fit.

• 12 mm is the common size on 1/10 cars, so most 1/10 wheels fit; offset and width still vary.
• The wheel nut is a separate size, so check its thread too before buying nuts.

Axle thread: A documented stock wheel, tire, or axle measurement. Stock dimensions alone do not establish the largest size that will clear the body and suspension.

• This working size comes from a replacement advertised for the identified OEM part. Confirm the fitted part before ordering; a replacement's size may differ.

Stock wheel diameter: A documented stock wheel, tire, or axle measurement. Stock dimensions alone do not establish the largest size that will clear the body and suspension.

Distance at the front axle per motor turn through its recorded gear path.

• This follows the listed gear reduction and tire diameter; it does not account for tire slip or deflection.

Distance at the rear axle per motor turn through its recorded gear path.

• This follows the listed gear reduction and tire diameter; it does not account for tire slip or deflection.

What the main chassis is made of and how it is built, as stated for this car. Braces, stiffeners and skid plates are not counted.

• Steel is heavy and strong; on a crawler that weight sits low and steadies it on climbs.
• A ladder frame is two rails joined by cross members, as on a full-size truck.

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 shaft size matters when buying seals, ends and rebuild kits.

The stock springs, in the maker's own wording: a color, a rate or a length.

• A stiffer spring holds the car up and resists bottoming out; a softer one lets it squat and follow rough ground.
• Rates are not comparable across makers unless they state the same unit.

The same measure at the rear, which differs from the front on this car.

Front lower shock bolt: A documented shock mounting interface at the named end and eye. A ball stud or standoff is distinct from a through-bolt. Match the mounting type, thread and eye dimensions when choosing a replacement shock.

Rear lower shock bolt: A documented shock mounting interface at the named end and eye. A ball stud or standoff is distinct from a through-bolt. Match the mounting type, thread and eye dimensions when choosing a replacement shock.

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.

• Front and rear run the same oil on this car, so both ends respond alike. Changing one end at a time is the usual way to shift the balance.
• 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.

Brushed motors are commonly described by can size and turns. No motor KV is published for this vehicle; turns alone cannot supply an exact value.

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.

• 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.
• Crawler ESCs usually have a strong drag brake, which holds the truck still on a slope when you let off the throttle.
• 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.
• Deans and other T-style plugs are older designs, still common on smaller cars and race packs.

The current the stock speed control is rated to carry, as the maker states it.

• The continuous figure is what it can carry all run; the burst figure only for moments, such as a launch.
• A motor or pack that pulls more than this risks the ESC.

The published size of the battery compartment or the stated maximum pack dimensions.

• Read the dimension labels beside the value, then compare with the battery's case size rather than its capacity.
• Allow room for the leads and the battery restraint.

Battery retention: A documented battery, motor, or ESC installation detail. Electrical ratings and physical fit are separate checks.

ESC mounting method: A documented battery, motor, or ESC installation detail. Electrical ratings and physical fit are separate checks.

Motor mount material: A documented battery, motor, or ESC installation detail. Electrical ratings and physical fit are separate checks.

• This working size comes from a replacement advertised for the identified OEM part. Confirm the fitted part before ordering; a replacement's size may differ.

ESC mounting dimensions: A documented battery, motor, or ESC installation detail. Electrical ratings and physical fit are separate checks.

ESC motor connector: A documented battery, motor, or ESC installation detail. Electrical ratings and physical fit are separate checks.

The stock servo that steers the car.

• Metal gears take hard knocks to the front wheels better than plastic ones.

How hard the servo can turn, at the voltage the maker rates it.

• More torque steers heavier cars and bigger tires more precisely and holds the wheels straight over rough ground.
• Kilogram-centimetres and ounce-inches measure the same thing; the other unit is converted for comparison.

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.

The distance between the front and rear axle centers. A longer wheelbase is steadier at speed and over bumps; a shorter one turns more tightly.

• On a crawler it also decides how well the truck clears a ledge without the chassis catching.