How 4 Ebike Motors Give Your Pedalling a Boost
The high tech behind smooth assistance
The high tech behind smooth assistance
It feels like having a tailwind all the time. That was the feedback Ben Pye, technical specialist at Shimano Canada, heard from a tester using the Steps system on an ebike. But that’s not necessarily the feeling you get from every ebike motor. Ebikes have been in North America for roughly eight years. Almost every major bike company has at least one in its fleet, which makes sense. Unlike those crypto-scooters with token pedals you see in bike lanes, ebikes require the rider to actually turn a set of cranks. That pedalling gets a boost from the battery-powered motor. Ebike motors fall into two categories: mid drive and hub drive. Mid-drive systems, such as Shimano’s Steps, are far more popular with bike companies than hub-drive ones. Why? A mid-drive motor makes an ebike feel more like, well, feel more like a bike.
Shimano Steps
One reason a mid-drive motor makes an ebike feel more bike-like is the placement of the unit. The mid-drive motor sits at a bike’s bottom-bracket area. “A mid-drive motor centralizes the weight and balances the bike better,” Pye says. “The bike’s steering and centre of gravity is very similar to what riders are used to.” Also, repairing a flat rear tire on a mid-drive ebike is the same as a regular bike. With a hubbased motor, flat-tire repair is a bit trickier.
Shimano introduced its Steps E6000 system in 2014 to a small test market in Germany and Holland. In 2015, it came to this continent for testing. It went live, so to speak, in 2016. In North America, the system is actually known as E6050. You see, we can ride a bit faster than the Euros. A European ebike motor can only provide assistance to 25 km/h. If you want to go faster, that’s all on you. In North America, an ebike motor can provide a boost to 32 km/h. Also, in Europe, Shimano has an off-road Steps system, the Xt-level E8000, to complement its city-bike oriented unit. The E8000 is likely coming to North America in 2018.
The Steps system relies on four sensors to provide assistance to your pedalling. Those sensors watch torque, speed, cadence and crank position. The 418 Wh battery on the Steps (or new 504 Wh battery) is designed to run in temperatures ranging from 50 C to -10 C, so even hard-core commuters can have pedalling assistance late, or early, in the season. If you are storing the battery in your garage, you don’t have to worry
“I was blowing the doors off of them on the climbs.”
about it until the mercury goes below -20 C. Of course, as with any battery, lower temperatures decrease performance. At more civilized temperatures, the battery will help you cover about around 120 km per charge in eco mode. The range decreases with the more assistance the motor provides, whether in normal mode or high. In 2016, Shimano introduced a new charger to lessen the charging time. On the old charger, it would take four hours to charge a battery that had been drained completely. The new charger will top up the cell in 3.5 hours. Also, the first 80 per cent of the charge is done in 1.5 hours if you need power in a hurry.
Another feature of Steps is a 6-km/h walk assist. Because an ebike is usually pretty heavy, you can turn on walk mode to help you move the rig up a hill as you look for a free post-and-ring to lock up. When the motor is paired with an Alfine Di2 hub, you can have “automatic” shifting. You can program the system to monitor your pedalling cadence. If your cadence drops below a certain range, the system will downshift. If the system notices you pedalling faster than the set range, it will upshift.
Finally, with the Di2 version, you can program a start gear. “Let’s say you want the bike to start in third gear every time you pull away from a stop sign,” Pye says. “If you pull up to a stop sign in sixth gear and stop for two seconds, the system automatically shifts to third. But, if you were climbing a hill in first or second and come to a stop, it won’t shift up to a harder gear.”
Giant Syncdrive Sport
Giant was one of the first companies to bring an ebike to Canada. For model year 2009, it offered the Twist Freedom DX with a Syncdrive motor on the front hub. For 2017, Giant Canada has three ebikes – the Quick-e+ for commuters, and the Dirt-e+ 1 and the Full-e+ 0 SX for the off-road set. They all use a mid-drive motor, Syncdrive Sport, that Giant developed from technology by Yamaha. “We have a great partnership with them,” says Giant Canada product manager Sean Kerr of the relationship between the two companies. “They have an office in our factory. We’re the only bike company that’s been allowed to get into that motor of theirs and fine-tune the mapping of the motor’s sensors. So, we’ve been able to customize how we want our bikes to ride.”
A hub-drive motor relies on sensors to assist your pedalling in a natural, unobtrusive way. In the case of the Syncdrive, there are four sensors: speed, torque, cadence and motor rotation. Software ties all the sensors together and decides how the motor will behave. Shimano and Bosch also have their own ways of handling data and managing their motors’ behaviours.
The 500 Wh battery on the Syncdrive is made by Sanyo/ Panasonic. Kerr says you can get roughly 100 km on it, but cautions that range depends on many factors. This past August, he took a Full-e+ 0 SX to the Chilcotin Mountains. “At the time, I didn’t know what I’d get out of the battery on that ride,” Kerr says. “I knew i’d have four hours of non-stop off-road riding. I rode in eco mode almost the whole way, bit on normal. But I never put it in power mode. I came out of that ride with more than 70 per cent left in the battery. I had way over-babied it.” The battery can be charged on-bike or off in about 2.5 hours.
On the Chilcotin ride, Kerr was with some top level riders, provincial champions, who are always nice enough to tone rides down for him. But this past summer, Kerr had the upper hand on some sections. “I was blowing the doors off of them on the climbs,” he says. “They were hanging off my Camelbak straps on an incline. It was a great day because that never happens to me.”
Bosch Performance CX
The Performance CX ebike motor by Bosch debuted in North America at Interbike in 2015. As with most things ebike-related, the off-road-oriented motor first appeared in Europe – in this case, a year earlier. The German company, however, has been involved in ebike motors since 2009.
“We’ve always been mid drive,” says Jonathan Weinert, marketing manager of Bosch ebike systems. “When the motor is adding on to your pedal power right at the cranks, it feels more seamless. You don’t feel as if you’re being pushed or pulled by something. You just feel stronger.”
Two figures that are commonly presented with an ebike motor are the watt hours of the battery and the amount of torque the motor can add to the cranks. Recently, Bosch released a 500 Wh battery for the Performance CX. A rider can opt to use that more powerful battery instead of the previous 400 Wh model, or switch between the two. The 500 Wh battery is four per cent heaiver than the 400 Wh one, but offers 25 per cent more range. The Bosch motor can put out 75 Nm of torque. “Some riders, if they are doing really steep trails, they just want as much boost as possible, or they’re looking for torque. That’s the key thing for them. But a high max torque can mean a trade-off in range. We have systems that don’t have as much torque, but you get more range out of the battery,” Weinert says.
When Bosch developed the Performance CX for off-road ebikes, the company had to improve the responsiveness of its system. On the trail, you need the motor to act quickly when you start pedalling up a tricky hill. You need power and traction. The Bosch system has three sensors that monitor pedal torque, wheel speed and cadence. “The electronics inside the system take measurements from those three sensors 1,000 times a second to ensure you get just the right amount of force, but not too much. When you are going uphill, you get great traction control,” Weinert says. He also says you can achieve a sense of uphill flow with such a motor.
Like the Shimano Steps system, the shifting on the Bosch system can go fully-automatic. In the case of the German company, its motor has to be paired with the Nuvinci Harmony internally geared hub. The system will monitor your cadence and shift to accommodate any changes it detects.
Pendix
Pendix, a German ebike system, approaches its mid-drive system differently than Shimano, Giant or Bosch. It’s more direct, if you will. “With the Shimano, Bosch and Yamaha, there’s a small motor that’s run through gears to drive your cranks. The Pendix is a big motor that acts directly on the crank,” says Dave Clifford, product manager for ebikes at Opus. The advantage of the direct drive is that it is quiet. Really quiet.
The left-side (non-drive-side) crankarm has the Pendix motor integrated into it. The system can be added to any bike with a bsa-threaded bottom bracket. “If you can change a BB, you can install that system,” Clifford says. The other Pendix components are its bottom bracket with a torque sensor and the battery, which mounts to the bottle-cage bolts on the down tube. Clifford spec’d the Pendix on the Opus Case+ not only because the motor is smooth and quiet, but it has a sharp, clean look. There’s no head unit. The charge on the 300-Wh battery is indicated by a coloured light near its top: green means fully charged; yellow, 70 per cent; orange, 40 per cent; and red, 10 per cent. You can select one of the three power modes – eco, smart or sport – by turning a dial on the battery. Pendix is working on an app so you can monitor the battery via Bluetooth. While the Pendix is available on the Opus Case+, the system isn’t yet available to Canadian riders looking to convert their bikes to mid-drive ebikes. It’s just a matter of time, though, as ebikes continue to get more popular.