First Ride: 2012 Zero S ZF9 review

Is it zero hour yet for electric bikes?

I WENT skydiving once (and once was enough, thanks). The overriding sensation as I fell out of the hole cut in the wall of the juddering single-engine aircraft – besides the feeling of my stomach and I being instantly hundreds of feet apart – was silence. Yes, the wind rushed past my ears at the speed of gravity's relentless pull, but overall, there was just falling, falling, and silence.

I thought about that earthward plunge last week, as I was slicing through midday traffic on the northbound A3 on my loan 2012-model Zero S ZF9. (I also thought about how much better speed was when horizontal rather than vertical.) A rare break in the miserable winter weather meant the road was dry and the sky was blue, and motorists were pushing a brisk pace. And every time I wanted to get past a car or two, I cracked open the throttle and shot past them, silently and swiftly, like those fluffy clouds I tumbled past years ago.

As a motorcyclist, twisting throttles and shooting past cars may seem like the most normal thing in the world. But doing it in complete silence was a novel experience, and knowing that what was powering me well past 70 mph was nothing but electron juice – well, that was pretty damn impressive. An hour later, dismounting back at Visordown HQ, I could only conclude: electric motorcycles have arrived. I know, I know, this is 2013, and electric/hybrid cars are common enough now that this isn't some sort of jaw-dropping futuristic technology anymore. No, what impressed was simply the fact that I'd just done a fast 50-mile ride running on the same stuff as the iPhone in my pocket, and come away thinking 'Well, that was fun!'

Fun, you cry in protest? Surely riding a hoover across the living room would be more entertaining than <sneer> an electric bike? I hear you; I like internal combustion engines as much as the next guy, and the sound of the Yamaha RD350B 'stroker twin I owned when I was 20 will always be the sound of a motorcycle to me. But I'll break it to you gently: riding the Zero S was, actually, genuinely, fun.

Californian manufacturer Zero Motorcycles has been around since 2006 and has earned thumbs-ups from the likes of Jay Leno and Arnold Schwarzenegger, but it has taken the company these six years to get to a stage where their flagship model, the sporty S with the top-spec ZF9 power pack, is not just a technology showcase but something you and I can take seriously. With an advertised range of 'up to' 114 miles (EPA cycle) and a claimed top speed of 88 mph, it's starting to sound like a real-world machine.

It looks like a proper motorcycle too, with its supermoto-esque styling and a rather dashing all-black-with-red-wheels colour scheme. The suspension, wheels, brakes and bodywork could belong to any bike, but not the power pack that sits between the twin spars of the aluminium frame, a non-descript rectangular block of a battery looking rather like a computer server from a decade ago.

The 9 kWh-capacity lithium-ion power pack is a 'double-stator axial flux permanent magnet brushless motor' and has a '420 amp, three-phase brushless controller with regenerative deceration'. No, I have no idea what that means either. The bike's overall build quality is good but not great, and there is a hint of the lashed-together about it when you look at it dead side-on, an angle that highlights the gaps between the frame, seat, and bodywork. But it is a complete-looking motorcycle.

Astride the narrow but comfortable seat, which is unintimidating to the short of leg, you turn the key and the instrument display and bright headlight come to life. Now what? No clutch lever, no gear lever, no engine noise... is it even working? A wee twist of the throttle and whoa, you're on the move, silently rolling forward, picking up pace. Keep it pinned and, suddenly, you are positively shooting forward – 40, 50, 60 mph arrive in surprisingly short, silent order. 

The brilliant thing about electric motors is that they make plentiful, constant torque, with an absolutely linear curve (a straight line, then). The ZF9 makes the leccy equivalent of about 25 bhp, about as much as a Suzuki Inazuma 250, but its 40-odd lb-ft of torque is 80% that of a Kawasaki Ninja 600! Plus, there's no transmission loss, as the clutchless direct-drive immediately hurls all that torque to the rear wheel via a belt.

There's a catch, however. Zero has intentionally moderated the S's power delivery below 30 mph, with the result that, off the line, its acceleration is below potential; you can feel a momentary hesitation when the lights turn green and you want to be sprinting away. This may be perfectly acceptable to someone migrating from a bicycle or a car to a Zero, but quickly gets irritating to anyone used to a combustion-engined motorcycle. That said, from 10 to 30 mph, the S will keep up with and indeed can outpace average city traffic; from 35 mph onwards, the 155kg Zero's acceleration to 65-70 mph is extremely strong, and the linearity of the surge never gets dull. Top speed is about 85 mph.

It helps that this turn of speed is complemented by a solid package of cycle parts: a 310mm single front disc and two-piston caliper which has good feel and power (one-finger stops are possible) and 17-inch wheels shod with grippy Road Winner rubber, suspended on 38mm inverted forks in front and a monoshock rear, both adjustable. Light and low, the bike is easy to flick through bends, pushing on the wide, flat handlebar supermoto stylee, and without all that clutch and gear fuss, you just drive out of corners on a fat wave of torque.