Hole new ball game
Why force air around a bike if it can go through the middle of it instead…?
There’s no reason for electric bikes to resemble petrol powered machines, yet all of them do… until now. This land speed record prototype by White Motorcycle Concepts has a tunnel through the middle, producing huge aerodynamic benefits. We ask the bike’s inventor Rob White about the prototype that could take him to 250mph on a salt flat and – potentially – increase the range of a generation of electric bikes.
What are the aero benefits of the duct?
If you can reduce frontal area, that’s a major part of your drag reduction, but what we’ve found with the duct [dubbed V-air] is that it also changes the way that the air separates around the bike. When the air hits the front of a normal bike it might have to travel 300mm or 400mm left, right, up or down before it can run along the length of the bike. With the duct, air doesn’t have to move that far to pass the mass that’s travelling through it. V-air reduces the bike’s aerodynamic resistance by as much as 70% compared with a high performance road bike according to the results of wind-tunnel testing at MIRA. If you could just get 15-20% less drag that would be utterly market disruptive. Could you imagine if you reduced the drag of a Moto3 bike by 20%? It would win every race.
Has there ever been anything like this?
The Britten [the radical V-twin racer created by John Britten in the early ’90s] was trying to get the air from front to back as smoothly as possible, but it was in a different way. We’ve opened up the centre section and faired in the body, whereas on the Britten they faired in the upper torso and tried to get the airstream split past the cylinder heads. I think maybe Britten might have come up with a similar concept to ours if they had the packaging options we now do.
Was it always going to be electric?
It doesn’t take long to see the benefits of housing an EV powertrain into a bike such as this. Motors are getting lighter, smaller and more cost-effective, batteries are getting more energydense, lighter and cheaper. What we’ve done now is probably the most difficult packaging that we’ll ever have to, because as the technology develops those parts will be easier to package.
Why has it got two wheel drive?
Due to the high centre of gravity of a motorcycle, you can only really harvest braking energy from the front tyre. To do that you need electric motors or some connection to the front wheel. In a conventional motorcycle you’d struggle to deploy energy through the front wheel because it tries to wheelie, but with less front lift we can do that [the tunnel dramatically cuts front-end lift at speed].
You’re aiming for a 250mph record…
You need a fair bit of power – 250kw upwards (335hp) – to reach those speeds, but on salt you lose traction before you’ve exhausted your power. The keys to success are traction and low drag, with power third in line. We’ll run on asphalt in the UK first, where we don’t have to worry about grip. For this first stage we’ll have relatively low power, about 100kw (134hp), but I think we can crack 200mph with that, and get a British record.
What about the future beyond records?
The Yamaha Tricity 300 is well suited to the retrofit of V-air [it’s got two
‘Could you imagine if you reduced the drag of a Moto3 bike by 20%?’
front wheels, like the Niken] and we’re just completing a proof-of-concept. In simulation we’ve seen a 25% reduction in aerodynamic drag. I’d love to see an OEM take the idea on and see what they could make of it.
Won’t people hate the weird looks?
I love bikes and I’m not going to argue about the appeal of a beautiful Ducati or Bimota. Generally, those bikes have a small tail unit and a low nose. As soon as you raise the nose for the duct entry, you get a form that’s difficult to navigate. With [designer] John Keogh’s talent we have sketched a few versions of a ducted superbike concept that are aesthetically quite appealing. But the duct is a sensitive thing, and to get the performance there’s a tug of war between form and function.