The Throttle and eBike Evolution
Do you need a Throttle on an electric bicycle?
For most people, the short answer is … YES! Twenty years ago, when I first became involved with electric bikes, all eBikes in America had a throttle. And people loved them as you could still pedal just like your regular bicycle, but also power them like a motorcycle -- or seamlessly apply electric power to your pedaling to help flatten the hills, cut the wind, or just cruise around. What a joy, and a revelation! For riders who were a little out of shape, had an injury, or were intimidated by hills, you could ride like a kid again!
For about ten years, every US electric bike was configured in this manner. The throttle also enabled you to feather in a bit power if you were slowly cruising by an art show or a farmer’s market, and gave you a ride home if you were too pooped to pedal. Enter PEDAL ASSIST -- the function where power would be automatically added to your pedaling effort. This was a nice additional feature, as long as you didn’t ditch your wonderful throttle. Most early pedal assist systems had just one power level, which boosted your pedaling effort about 50%, helping conserve battery life, though limiting top speed. But many manufacturers started offering bikes that were ONLY pedal assist which was a turn-off for many prospective ebike riders. Why in the world would they ditch the beloved throttle? The answer was simply that throttle bikes were illegal in Europe whose market size dwarfed the secondary US market. Europe also had a 250 Watt limitation on the size of the motor, so many bikes were pedal assist only and just 250 Watts of power. These early manufacturer’s didn’t want to design a US specific machine.
Around 2010, as the US market matured and models were designed specifically for America, most electric bikes integrated both features, and added multi-level pedal assist -- giving the rider the best of both worlds. The better Hub motors got more efficient, powerful and totally dependable. And the better brands employed higher quality Lithium Ion batteries with advanced chemistries providing longer life and lighter weight. However, many models still positioned the battery on a rear rack, causing the bike to be unbalanced toward the rear. In 2013 and 2014, new designs with more creative and better battery integration began appearing bringing back the balance of what a bicycle needs to be. In addition, the electronic parts all became modular and plug and play so they could be easily replaced if necessary. In my opinion, an electric bike with the battery on the rear rack is simply ... obsolete.
The Mid-Drive and the Hub Motor
Enter the Mid-Drive motor, another design for keeping the electronics balanced and at a low center of gravity. This design adds power to the gears of the bicycle which can yield a very high efficiency for the rider, and eliminate the weight of the motor in the wheel. This is particularly ideal for the off-road Mountain bike rider switching elevations in demanding terrain. Though the mid-drive can have many advantages, the throttle is usually eliminated, and pedaling is necessary to get the full benefit of using the gears. One key issue with mid-drive motors is that they are limited by the strength of the chain and the sprockets. To date, almost all systems use standard bike chains and sprockets, which were never designed for motorized use, so the power has to be kept quite low and inevitably, a crank drive will lead to increased maintenance on the drive chain and gears. This is a newer and emerging technology, going through many design modifications as it matures. That being said, there are some amazing off-road mountain bikes on the higher end of the price scale.
At this point, the trusty hub motor (originally invented by Nikola Tesla), with a throttle and pedal assist is a refined and mature system. A good sealed hub motor is zero maintenance, and now with ‘quick disconnect’ plugs, changing a tire is as simple as a standard bicycle. And for most riders who just want to add power to their pedaling, they are simply more fun.