+ Click to Enlarge ECO-FRIENDLY POWER: The 125cc eCycle is driven by hybrid diesel-electric power and the makers claim fuel efficiency of 1.74 litres/100km.

October 11, 2001
By Dave Abrahams

AMERICAN technology developer eCycle claims it is possible to build an environmentally friendly hybrid superbike capable of 270km/h and has already built a 125cc diesel-electric prototype that pulls wheelies and will do 130km/h.

The bike has Marchesini wheels, Grimeca brakes and a Penske rear shock. This is no motorised bicycle - its makers say that one day all bikes could be made like this and that there’s no limit on the size of the motor.

“Our customers will be thrilled to buy a 125 bike that wheelies and gets at least 1.74 litres/100km - as well as handling and stopping better than anything on the road.” said eCycle’s Dan Sodomsky. “If we made a one-litre bike with that technology, it would be at least as good as what is available now and I think it could easily reach 270km/h.”

The e-Cycle has two motors, one electric and one diesel. Since an electric motor provides its maximum torque a zero revs it does all the work up to 25km/h with power coming from a 156-Volt DC battery pack and kicking out 10kW. At 25km/h the diesel starts up (it doesn’t even run below that) and both motors provide maximum power for acceleration.

Once at a steady “cruising” speed the computerised management system cuts out the electric motor and, since it is still coupled to the drivetrain, it’s used as a generator to recharge the battery pack. If you need to accelerate the electric motor kicks in again to provide the extra torque.

The engine and electric motor are seamlessly integrated by the fully electronic power management of the eCycle. In fact the only giveaway is the sound of the engine starting and stopping around 25km/h.

The diesel always runs within the fairly narrow limits of its optimum operating range so it can be smaller and more efficient while the electric motor does the rest.

The diesel is an alloy 125cc air-cooled two-stroke twin producing 7.5kW.
It’s fed by Parker Aerospace Macrospray injectors, originally developed for use in
aircraft turbine engines. Compared to conventional small motors it runs hot, with very high compression - both of which make it more efficient.

It’s based on the unique eCycle rocker crank mechanism that has a one-piece piston and con-rod moving in a straight line. Thus the cylinder and crankcase are entirely separate, divorcing the combustion and lubrication processes. This means that the engine uses practically no oil and burns as clean as a four-stroke while oil change intervals are much longer since the oil stays free of contamination - up to 100 000km.

E-Cycle claims that their motor is simple, light (just 6.8kg), cheap and easy to build.

The electric acceleration comes from a three-phase, permanent magnet, brushless motor rated at 5kw continuous and 15kw peak power. It weighs 6kg, runs on 156 volts of direct current with a peak current of 75 amps. The voltage is provided by a hybrid battery pack containing 13 12V 5Ah sealed lead acid batteries, connected in series for 156V nominal voltage.

The total weight of the battery pack is 26kg.

The eCycle gearbox is a simple constant mesh two-speed unit, running on ball and needle roller bearings, with a slipper clutch for smoother shifting - and to prevent rear-wheel lockups under braking. Final drive is by a Gates Polychain II belt, as used by Harley Davidson.

The whole thing is held together by a light steel and alloy frame that also acts as a heat sink for the battery pack and electronic components. The batteries are mounted low and well forward in the chassis to provide a fashionable front-biased weight distribution while the single-sided alloy swingarm houses the gear-box and final drive.

Front suspension is by courtesy of a pair of FAR 48mm upside-downies while the rear rides on a Penske Racing shock-absorber - the first time one of these superb units has found its way on to a commercially built road vehicle.

The front brake has a single 298mm disc under a four-piston Grimeca calliper. The back wheel sports a 216mm disc and a single-piston calliper.

Sodomsky concluded: “There is interest in the bike from around the world and a large Chinese company is looking at making a major investment soon.”

The company hopes to market the hybrid motorcycle in 2002 at a projected dry weight of 105kg (although the prototype in the picture weighs in at 132kg) with a top speed of 130km/h and 0-100 acceleration in six seconds. The target retail price is US$5 000 (about R42 500).

The 270km/h hybrid superbike will come later.

SPECIFICATIONS

Motor: Air-cooled two-stroke diesel twin.
Capacity: 125cc.
Power: 7.5kW.
Induction: Parker Aerospace Macrospray injectors.
Ignition: Compression.
Starting: Electric.
Transmission: 2-speed constant mesh with final drive by belt.
Suspension: 48mm FAR inverted cartridge forks at front, Penske Racing hydraulic shock absorber at rear.
Brakes: 298mm disc with four-pot opposed piston Grimeca calliper at front, 216mm disc with single-piston Grimeca calliper at rear.
Tyres: Front: 110/70-17 tubeless. Rear: 130/70-17 tubeless.
Wheelbase: 1321mm.
Seat height: 762mm.
Dry weight: 132kg.