The following is excerpted from a Cycle World post by Ben Purvis about Honda’s patent application for a regenerative-braking system for hybrid and/or all-electric motorcycles based upon the two-wheel machines being two-wheel-drive motorcycles. The article contains numerous images and illustrations from the patent application.
TOKYO — One of the key technologies used by virtually every electric and hybrid car on the market is regenerative braking—or reversing the flow of power to recharge the batteries when you’re slowing down—as a way to boost range. But the same idea has yet to be fully exploited on motorcycles for one simple reason: We do almost all of our braking with the front wheel, and send drive exclusively to the rear.
Funky New Honda Bike Patent Has Drum Brakes
In cars, the braking effort is more evenly spread, and many put their power down though the front wheels, making the job of using electricity regeneration much easier than it is on bikes. However, the rewards of regen are potentially significant. Every time you hit the brakes, the forward motion that you burned fuel (or used electricity) to create gets converted into heat and dissipated into the air. If you can recover that energy and reuse it later, it’s a much more efficient way of operating.
A motorcycle’s weight transfers significantly to the front during braking, and the rear brakes are barely used in most cases. But that weight transfer also means using the rear wheel for regen-braking-to-drive isn’t always most efficient. Honda has been pondering precisely this problem, and it’s come up with a solution that involves making a hybrid or all-electric bike that’s two-wheel drive.
The obvious solution here—and one that’s been experimented with by various bike firms already—is to add a small electric motor/generator in the front wheel hub. But with such a vast amount of braking done with the front wheel, it’s unlikely that such a design could efficiently recover the maximum possible energy. Honda’s solution doesn’t use any electric connection to the front wheel but relies on hydraulics instead.
Will the patent ever become a viable production machine? Your guess is as good as ours at the moment, but given the potential increase in range and efficiency that effective regenerative braking offers, there’s a significant carrot dangling in front of the company that can crack this conundrum, particularly as ever more bikes move to electric power.
To view the entire post and images, click HERE.