The Throttle and eBike Evolution
Do you need a Throttle on an electric bicycle? Absolutely
For most people, the short answer is … YES! Why? For starting out, accelerating away from danger, crossing a street, boosting your speed, or just for when your legs are tired. You know you always have a ride home! For most people riding on the street, I believe a hub motor eBike with both a Throttle and Pedal Assist is the appropriate system, despite the strong emergence of Mid-drive bikes and the powerful push by Bosch, Yamaha, and other well-subsidized advertisers. Of course, the mid-drive is great if you are an electric Mountain bike rider climbing and dropping on variegated terrain.
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 add power and ride just like a motorcycle. Suddenly, you could 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 the hills -- you could ride like a kid again!
For about ten years, all US electric bikes 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 companies' started making 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 of the US bikes were configured as pedal assist only and just 250 Watts of power. These early manufacturer’s simply 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 chemistry 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 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 bicycle's gears.
However, with the mid-drive, there is a continuous need to correctly time your shifts, and not doing so can cause motor, battery, ECU over-heating and thermal shutdown and thus poor performance. In addition, you NEED to shift the gears to get the benefit of the assist. And, the mid-drive will inevitably create increased wear and damage to the drive-train -- chain, derailleurs, gears and frame (even when shifted correctly). Most mid-drive system's 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 mid-drive will lead to increased maintenance. Higher priced premium mid-drive systems are starting to use proprietary hardened parts, but you'll have to pay way up for them. This is a newer and emerging technology, going through many design modifications as it matures.
That being said, there are some remarkable off-road mid-drive mountain bikes on the higher end of the price scale. My basic feeling is that Mid-Drives might be best for hard-core off-road riding and hub motors best for the street.
At this point, the trusty hub motor (originally invented by Nikola Tesla), with a throttle and pedal assist is a refined, perfected, and mature system. A good sealed hub motor is zero maintenance, totally dependable, and now that they feature ‘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 or push the trusty throttle -- they just are simply more fun.