RC trouble desk · no login needed

Your car's acting up. Let's find out why.

Pick what it's doing and we'll walk you to the likeliest cause first — ranked by how often it's the real culprit — with the exact checks to run. Built by bashers, for bashers.

Now on iPhone

Every tool here, in your pocket, working offline at the track. Free, no login.

Download on theApp Store

Step 1What's it doing?

18 common symptoms mapped

80+ ranked causes

free · no account

Wrench library

The know-how behind the diagnoses. Short, no-fluff guides for the jobs every basher hits sooner or later.

Heads upThese guides cover general principles that apply to most hobby-grade electric RC cars. Specific figures, like diff oil weights and gearing, are starting points from the wider hobby, not fixed values for every car, and some steps only apply if your car has that feature (oil-filled diffs, a steering damper, a tunable pinion). Always check your own model's manual for exact specs.

Gearing & speed

Before you fit a bigger pinion, check what it does to your top speed and heat. Drag the slider — the gauge sweeps from safe into meltdown in real time.

Build sheet

Motor KV (brushless)

Cells

Tire mm

Internal ratio

Spur T

Pinion teeth22

Final drive

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Motor RPM peak

—

Rollout

—

Top speed

—

Heat & stress

0mph

0SafeCautionMeltdown100+

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Reverse gearing finder

Know the top speed you're after? Enter it and we'll tell you the pinion to fit, and warn you if it'll run hot.

Target

Target top speed (mph)

Motor KV

Cells

Tire mm

Internal ratio

Your spur teeth

Fit this pinion

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Final drive

—

Actual speed

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At full charge

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Scale speed converter

Your real speed times your car's scale. This is the number that makes non-RC people's jaws hit the floor.

Real top speed (mph)

Your car's scale

Scale speed

360 scale mph

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Get the app

The site works fine in a browser. The app is the version you want in the pit bag, it runs completely offline, so it works at the track whether you've got signal or not.

Works offlineThe whole diagnoser and every calculator lives on your phone. No signal needed at the track.

Built for your thumbTabs at the bottom, haptic feedback, and a share button for sending a diagnosis to a mate.

Free, no accountNo login, no tracking, no data collected. Open it and use it.

Download on theApp Store

The pit crew

Stuck on something the diagnoser couldn't crack? This is where bashers will post problems, show off builds, and swap setups, a place to get a second pair of eyes from people who've been there.

Opening soon

The pit crew is just getting started

No threads yet, the forum opens once the doors are. When it's live, this is where build logs and tough fixes will live.

Try the diagnoser meanwhile