The Conway E-Rider is a German off-road E-bike that has high ground clearance, full-suspension with long travel, and a centrally-located non-hub motor with a factory frame-mounted battery. There are two models, the “Performance” and the more expensive “Extreme“.
The motor is an outrunner about the size of a large coffee cup. A smaller motor can put out high power if you spin it very fast and then reduce the shaft speed down to a usable RPM with belts or chains. The Conway has opted to use a triple reduction using chains, with the primary and secondary being housed to keep the chains clean, to keep out anything that would entangle with them (safety), to keep the noise down, and to hold in the vital lubrication.
You can achieve the same wheel power with fewer reductions if you use a larger motor, so it appears Conways design concern was keeping the bike as light as possible, and keeping the weight of the battery and motor as centrally located as possible.
The biggest problem with outrunner style motors, is keeping them cool when under extended peak loads. A small improvement can be achieved by adding an air- fan (as seen in many RC helicopter outrunners). Conway has chosen the route of potting the stator in a thermally-conducting epoxy to aid heat-transfer from the hot coils to the aluminum baseplate (the heat-generating controller FETs are also attached to that same aluminum baseplate). Although it’s not visible in the pics, the motors aluminum baseplate is purposefully attached to a section of the aluminum bike’s frame, making the frame a heat-sink. I suspect that heat will not be an issue with this well though out system.
Many European nations have silly restrictions on E-bike system power, and when an E-bike doesn’t have much power to work with, it’s worth the hassle and cost to give the modest motor some gears. For the last few years, there has been a growing appreciation for a BB-drive as the easiest and cheapest way to give a motor some gears.
Off-road bikes have no power restrictions, so there are some exciting things happening in the European off-road scene. The Conway is proof that a company with significant engineering resources has studied every possible option, and came to the conclusion that giving the motor some gears with a light but powerful BB-drive on a DH frame using well-established engineering principles was the best possible choice for their upscale customers.
Price for the “Performance” is roughly 5,500 Euro’s, and the “Extreme” is 7,000 ($7,340 / $9,340 USD this month). We have been unable to find a North American dealer yet.
Aluminum frame, 7020-T6
7 /14-speed using derailleurs, electric BB-drive
20 kilograms (44 lbs.)
Dual-crown fork with 160 millimeters (6.3-in) of travel
48V Lithium-Ion battery
324-WH / 695-WH
Motor is a “CPM90-22-1000 A” (Compact Power Motors, GmbH), 1,000W continuous, 2,000W peak (1.4-HP, 2.8-HP)
triple-reduction using chains from the motor shaft to the BB