Soapbox Race
How to build a winning Red Bull Soapbox racer
Nick Hunter, captain of 2019's UK champions Gas Gas Gas, reveals his tricks and tips for building a dream machine...
Red Bull Soapbox Race isn't your average road race. Comic-Con meets Formula One, it's a beautifully daft event involving daredevil driving, crazy obstacles and vehicles that truly push the limits of their builders' creativity.
"You’re judged on three things," says Nick Hunter, captain of 2019's UK champions Gas Gas Gas. "What you’ve built, your start line performance, and the run-time to the end of the course. Whereas other soapbox racing events are looking for the fastest entry, here it’s more about flair and creativity, putting on a show for the crowd."
Winners Team Gas Gas Gas
© Leo Francis
The competition is as much about flair and creativity as it is speed
For Nick and his team (all of whom are design engineers for a company that produces equipment to protect soldiers from chemical warfare agents and gases) their debut race in 2017 proved a real learning curve. Appearing inside a giant gas mask on wheels, they crashed out spectacularly on the slopes of London's Alexandra Palace, went back to the workshop and returned two years later to claim the title in a heavily modified car.
With the return of Red Bull Soapbox Race in 2022, strap yourself in as Nick reveals how to build a winning vehicle...
1. Have a solid chassis
"You want to start with a nice stable chassis. The easiest option is to use something from an old existing vehicle — I’ve seen teams build soapbox cars with something they’ve picked up in a reclamation yard, like a sit-on lawnmower, where they’ve stripped everything off except for the base and the wheels and built on top of that. Trailers also work. We've always built a custom frame, using plywood because it's got a nice light weight yet good structural strength. And having a flatter frame with wheels a little stretched out helped to keep it balanced."
2. Keep the bodywork light
Things falling off is okay – it's sacrificial bodywork!
"Your outer frame needs to be lightweight so you shouldn’t be bothered if it gets damaged. Some teams use polystyrene, others use cardboard which is also great as you can form it, bend it and turn it into the shapes you need before painting it. It’s with the bodywork where you will have most fun in being original. We lost a cardboard air intake box during our winning run — things falling off is okay, as long as it doesn’t affect the speed, it’s sacrificial bodywork. The rest of the car held up pretty well."
Action from Red Bull Soapbox in 2013
© Nathan Gallagher/Red Bull Content Pool
Red Bull Racing's ultimate Soapbox building tips
3. Use the right wheels
"You’ll see lots of teams using wheels they've got from prams or bicycles, which is fine, but they can collapse quite easily. We wanted something more substantial as a thicker wheel definitely makes the car more stable, whereas thinner wheels at higher velocity can cause a speed wobble. Our rear wheels came from an old moped, while our front wheels came from a trailer on a farm, although we ended up buying new tyres for them."
4. Don't forget the brakes!
"Before the build, you're provided with a set of regulations. One of which is that the brakes must work on a minimum of two wheels. You can build it as basic as rigging up a pulley system where you yank a piece of rope which presses down two bits of wood on top of the wheels. Handily, the moped wheels we'd repurposed already had the rotors for a disc brake system. We also picked up an old pushbike at the scrapyard to help us create a cable-type system. We then pulled a lever off an old office chair and used that as our brake pedal."
5. Give it the shock treatment
"Soapbox cars can take quite a bump over the ramps, especially those with rigid frames. In 2017 I felt the brunt of it when we crashed out. Two years later we had a helping hand from Pro Tech Shocks, a company who make suspension for race cars; they were nice enough to gift us four suspension units. Our job was to then come up with a design to fit them into the car. Although the easiest way to get good suspension is by repurposing the forked suspension from an old bicycle. We saw many teams who took this approach and did quite well in the race."
Fans lap up the action at Red Bull Soapbox London
© Nathan Gallagher / Red Bull Content Pool
6. Call in as many favours as you can
"To say thank you to Pro Tech Shocks we stuck some of their stickers on the soapbox at the race. It’s always helpful to call in favours, begging or borrowing stuff for your build. We managed to get another local company to waterjet cut some of the parts for our chassis, a local go-kart track donated a seat for our driver to sit in, and we found somebody else who gave us an old steering wheel. You’ve definitely got to scrounge around and see what you can get."
7. Think outside the (soap)box
"We had been working on a fake engine block for the car, when one of our team, Seb, suggested it would be great if we had some pistons on the car, using a battery drill mechanism to make them move. Riffing on that idea I said the pistons could be Red Bull cans, and so we did it. When the judges came over to check the kart for creativity that was one of the wow features. It also helped draw crowds for the public walk-through."
8. Steer clear of imbalances
"For 2019's car we bought a go-kart steering column on eBay and used that as our steering arrangement. With a bit of spare metal, we then made rods which we attached from the steering bracket to our wheels. It’s tricky to get the steering right on a build — you don’t want too much sensitivity but at speed you still want good control. That’s key for having confidence in the car. So ensure your steering column is securely fixed, and also that there is a good clearance around the wheels so that, when you do steer, it doesn’t rub the bodywork."
Making a splash at Red Bull Soapbox Race London
© Leo Francis
9. Don’t overload your front end
"When you’re pushed down the start ramp there’s usually a gap where the ramp meets the road. You need a bit of ground clearance built into the front of the soapbox to compensate for this divot, as some of the bodywork can break off around this area at speed and get stuck under your car. That actually happened to us in 2017 when a bit of polystyrene came off and we ground to a halt after the second jump. In the end the marshals had to push us."
10. Play to your strengths
"You might not be an engineer, but you can certainly work a build around what your team are good at. The competition is as much about flair and creativity as it is speed, and I’ve seen some incredibly inventive teams capable of creating a soapbox racer everyone wants to see. In 2019 it was Bumblebee from Transformers which drew a lot of attention. Their team actually had people who could weld and were able to build a custom frame out of metal, it's all about spreading your skills.
Champagne with Gas Gas Gas
© Mark Roe; Red Bull Content Pool
11. Find a theme
"We all worked for a company that specialised in respiratory equipment so it made sense [to race in a giant gas mask in 2017]. Going into 2019, we decided to push the story forward, explaining in our application video that the crash two years previously meant that an antidote to stop a zombie invasion was still on a hill at Alexandra Palace, and that our new driver was the latest hero to take on the mission."
12. Keep well padded
"Working for a company like ours we were able to borrow products for the costumes, including a full helmet with respirator for the driver. And thanks to the military-like gear and general zombie apocalypse theme, he was able to stay well padded, with knee and shoulder pads while looking the part. You do get some spectacular crashes at Red Bull Soapbox Race, it's on tarmac and yet I have seen people driving in Lycra!"
13. Learn from your mistakes
"If you've raced a soapbox before then have a real think about your design and what you can do better. When I crashed out in 2017, our steering column wasn’t fixed to anything. We had two people sat side-by-side, passing the wheel to each other because it was on a universal axis. It was a novelty but it proved detrimental to our handling ability. We ended up using the same sort of chassis again in 2019, but just honed and stiffened it so it was more suited to the course. We also went from two seats to just having one driver who was now sat much further down, giving us a lower centre of gravity and more control downhill.
14. Test your car properly
"This is an important one. During our first event we tested the car on some small hills without going over any jumps. It was a big mistake. By race day it turned out our suspension was way too soft, too unstable. It almost collapsed. Do your best to make sure the suspension and car as a whole holds up at high speed, giving yourself plenty of time to make any fixes if you need them."