Kart Building Tips
Provided by Peter Bowden, Founding Kart Scrutineer
Building your first kart might seem like a challenge, but don’t panic—it only has to survive two or three runs down a 750-metre track! That said, it will need to handle a couple of sharp corners, hold up under heavy braking at the finish, and be sturdy enough to tow up to nine other karts behind it. No pressure, right? Over the years, we’ve picked up a few tricks of the trade to help you build something fast, strong, and ready to take on the course.
Sourcing Parts
Karts come in all shapes and sizes (within the Technical Regulations, of course!). Some of the most creative donor items have included push bikes, ride-on lawnmowers, kid’s pedal karts—even a piano! Push-bike-based karts are a popular choice, and you might find a usable bike through friends or neighbors.
A word of warning—don’t bother checking your local Civil Amenity Site! I tried once, thinking I could "recycle" an old bike, only to be told that nothing entering the site could be taken away. Ironic, right?
Wheels
One of the trickiest parts to source. Bike wheels are plentiful, but keep in mind—they’re not designed to handle high side loads, something they rarely experience in normal cycling. If you're going the bike wheel route, consider the weight of your kart and riders.
Mountain bike wheels can handle around 60-80 kg in a vertical direction—but may struggle under increased side loads.
BMX wheels are more durable and widely available—better for handling stress but still not perfect for side loads.
Workshop trolley wheels can work if you want something extra robust.
Brakes
Absolutely critical—your kart must have efficient brakes. Be cautious about using kids’ bike brakes—they aren’t strong enough! The issue is that child-sized brake levers don’t have much leverage or travel. Swapping in adult levers won’t help—the calipers will just bend or break.
Adult bike brakes work well, but don’t cut corners on installation. Some builders have used moped, scooter, or motorcycle brakes, which have proven to be reliable.
Fabrication
This is where things can get intimidating—not everyone has access to welding equipment. If you need help, Tom Webb at The Forge Motor Company can assist with welding at reasonable rates. Reach out to Tom at 07854370870 or tommwebb223@hotmail.co.uk to discuss your kart needs.
For in-depth kart-building advice, check out Facebook Soapbox & Gravity Racing UK.
Final Thoughts
Kart building isn’t as daunting as it seems—after all, it only needs to survive two or three runs down the track! Keep your design solid, your brakes strong, and your creativity wild—and you'll have a kart that stands out on race day.
Best of luck, and see you on the course!