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clutch

What is a clutch and why do you need one? Learn how they're used for tuning both electric and nitro RC cars.

Diagram of the slipper clutch on a TLR 22 5.0 DC Elite

Electric RC cars and nitro cars use different types of clutches, and some use no clutch at all. Read on to learn about the types of clutches.

Electric cars

A slipper clutch allows the drivetrain to "slip" slightly as the car accelerates. It is intended to increase traction by preventing excessive wheelspin.

Direct drive (no clutch)

  • Faster throttle response
  • Less weight and rotational mass
  • Requires more throttle control, especially in less-than-ideal traction conditions
  • For off-road, this is sometimes used in stock racing applications where the increased throttle response is very important.

Slipper clutch

  • Slower throttle response
  • More forgiving to drive / less likely to break loose under power
  • For off-road, slipper clutches are common, although some 4WD cars use a center differential rather than a slipper clutch.
Side view of a slipper clutch at right. The spur is usually "keyed" to the clutch pads, so they rotate together. The pads slip against the clutch plate as the car accelerates, reducing the amount of power sent to the wheels and making the car easier to drive. Once the wheels get up to speed, the clutch stops slipping and all power is sent to the wheels.

Nitro cars

Nitro cars use a clutch to allow the engine to continue to spin even when the car is not in motion. As you pull back on the trigger and increase the rpms of the engine, the clutch engages, making the car move forward.

The speed at which the clutch engages is controlled by the clutch shoes and clutch springs, so please see those articles for more information on how to tune the car's response via the clutch.

The clutch shoes and clutch springs are contained within the clutch bell, as seen below. The clutch bell is usually one piece with the pinion gear. Read more about how the clutch works in our article on clutch bells.

Diagram of the clutch on an HB D819RS