How does a reverse gear make a car go backwards?

An extra idler gear flips the direction. Two gears touching always spin opposite ways. Put a third gear in between and the output flips back. A reverse gear is just an extra gear you can switch into the path, so the car drives backwards while the motor keeps spinning the same way.

Try Reverse-Gear Truck for free

Gearbox & Drivetrain Cars booklet pack: 30 PDF booklets for $5.99. Instructions only; individual booklets remain free.

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Try it yourself

Build a line of 2 gears, then 3 gears. Which way does the last one spin each time?

Build it: the build that teach reverse gear

  • ↩️ Reverse-Gear Truck: The motor only spins one way — the gear lever decides forwards or backwards! (level 4 of 5, about 55 minutes, 18 steps)

Common engineering questions

How can I try reverse gear at home?

Build a line of 2 gears, then 3 gears. Which way does the last one spin each time?

Which builds teach reverse gear?

One MightyCog build teaches it: Reverse-Gear Truck. Start with Reverse-Gear Truck: 18 steps, about 55 minutes.

Ideas that go with it