SILENCE. It’s not a word normally associated with motorcycles but, at 60 km/h, this is exactly what you experience aboard the Zero DS ZF11.4. Okay, not complete silence. There is the slight flutter of wind rushing past your helmet, the noise of fluid working in the dampers of the suspension and a faint whine from the electric motor. Grabbing the front brake to stop at a traffic light, I’m surprised at the unusual sound of pads grating on the single disc to slow progress. The loudest racket, however, is caused by the stationary-but-idling vehicles at the red light that pump toxic gasses into the atmosphere.
Californian-based electric-vehicle company Tesla (founded by South African Elon Musk) surprised the automotive world when it launched its first fully electric production vehicle, the Roadster, in 2008. This forced other carmakers to take the electric transformation seriously and developed EVs of their own.
And now the trend has crossed over to the motorcycle realm. Zero Motorcycles, also based in California, started producing electric motorcycle prototypes in 2006 and currently has four production models. The question therefore is: when will mainstream motorcycle manufacturers take note?
It was with some trepidation that I collected our test unit … images of small electric scooters and kid’s toys plagued my mind. Seeing the bike in the underground car park came as a relief. It was indeed a “real” bike and all the necessary elements were in attendance: fully adjustable, upside-down forks up front and a single shock at the back; a 19-inch front and 17-inch rear wheel; sturdy looking alloy frame; and wide handlebars.
The powertrain consists of a 11,4 kWh battery pack (hence the name ZF11.4) and a 40 kW aircooled electric motor that’s connected to the rear wheel by a carbon-fibre belt that results in a fixed gear ratio. No clutch is needed, as electric motors produce almost maximum torque at zero engine speed.
Starting the bike is as easy as turning the key before keeping an eye on the initialisation process on the instrument cluster (until a green light confirms the Zero DS ZF11.4 is ready). The readout is clear and the analogue rev counter marked to 7 000 r/min, a digital speedo, trip meter and a “fuel” guage displaying the battery’s state of charge.
Twist the grip and you get seamless thrust all the way to the (claimed) top speed of 158 km/h. With such immediate power on tap, Zero’s engineers have opted for a safety-first approach and have developed a soft-throttle calibration (even in sport mode; see Connected bike? below).
With 92 N.m of instant torque, it would have been easy to create a wheelie monster of note, but this is not the case in the DS. The front wheel stays firmly planted during full-bore pull-aways and the acceleration gradually builds as the speed of the electric motor picks up. The bike is by no means slow and can easily leave traffic behind. Even cruising at the national speed limit is an effortless affair.
The handling is predictable, aided by the low centre of gravity created by the placement of the batteries and electric motor. Although the bike is designed for mild dual-purpose use, it’s more suited to paved roads.
Using the bike in a spirited manner dramatically reduces the battery range (and challenges the cooling performance of the electric motor). In our enthusiastic use, the range from full to flat dropped below 100 km. Exercise restraint and the bike should be able to achieve closer to 200 km between charges. Topping up the electrons is as easy as connecting what looks like a long kettle cord to your household electric socket (an onboard charger is provided). At the normal charging rate, it takes about seven hours for a full recharge (a fast charging option can halve this time).
The best part is the cost: at around R1,50 per kWh, a full charge amounts to just R17,10. The equivalent petrol consumption cost (at R14 per litre) is therefore between 0,61 and
1,22 litres/100 km depending on the riding style (a comparable petrol-powered bike consumes an average of 5,0 litres/100 km). The fact the Zero needs almost no maintenance and the battery has a warranty of five years or 160 000 km make the high R162 000 asking price (the Achilles’ heel of most new technologies) easier to swallow.
Considering the price, does the bike rival existing motorcycles? The short answer is no. The rear suspension is too firm, which compromises comfort, the rear brake is more of a token item, ABS and traction control are absent, some of the switchgear is hard to reach and the limited range could be a problem (that said, many of these issues will be addressed with the new-for-2014 range).
However, to lambaste this bike would be missing the point. It provides a taste of motorcycling’s future. Whether you’re an early adopter/eco warrior, or simply want to experience the smoothest motorcycle powertrain in the market, a test ride is a must.
Connected bike?
The Zero Motorcycle App allows you to connect your smartphone to the bike via Bluetooth. The owner can then calibrate economy mode (which is activated with a switch behind the handlebars) by setting the maximum speed, maximum torque and level of regenerative braking, among other items, to maximise range. The app also displays the state of the battery and how long a full charge will take.
