Techwatch: Cars v bikes: let’s be grown up about this
03 May 2013 10:00
For acceleration it’s two wheels, but what about braking?
Down the pub, we all like to imagine ours is the best. But in a no-holds-barred shoot-out, who gets there?
Let’s start at the start. Bikes launch phenomenally well, putting all their weight onto the driven wheel and becoming “all wheel drive” by virtue of there only being one on the road. It’s important to lean forward and not let the bike lift, but even quite modest bikes post blistering 0-60 times compared to cars thanks to this effect.
As the speed comes up, bikes have the drag coefficient of Cologne cathedral even with their modest frontal area – around a quarter of a car - they still need quite a lot of power to reach a given speed. This has the by-product of meaning they rush up to their maximum speed comparatively quickly, where a car takes an age to put on the last 10% of their speed.
Braking for the first bend is where it all goes wrong. Despite being able to launch at up to 1.4g, few bikes can brake at anything over 1g. The limit is the rear wheel lifting – the rider can’t really lean back over the rear wheel.
Into the bend and bikes are back to parity, with a good bike cornering like a good car, at just over 1g – the limit is the rider’s nerve. With bikes being so much narrower than cars, a wide array of lines are possible on a given bend, which can make up for a lot by turning in late and firing out of the corner like the MotoGP bikes do.
Getting out of the corner is technically comparable but quite difficult to achieve in practice. A little slide in a car while you feel your way back onto the throttle is nothing like as distressing as the same event on a bike. No, really.
So, which is it? Well, it all depends really – but don’t try outbraking a really sporty car any time soon, it will end in tears. Performance-per-pound - now that’s where you want to lead the conversation next.