Engadget shreds on the Zero S all-electric motorcycle (with video!)

By Tim Stevens

posted April 23rd 2009 11:08AM

Review

It's not the first. It's not the fastest. It's not the lightest, the strongest, the cheapest, or even the best looking electric motorcycle out there. It is, however, one of the very few you can order today and, when it ships next month, ride it (legally) on the highways and byways of all 50 states. Europe, too. Among that very limited group the Zero S electric supermoto (or electrimoto as we've taken to calling it) is certainly a standout, completely custom-built around battery and motor, and we were lucky enough to take it for a spin on a hazy, dingy, frequently traffic'd New York City side street -- just the sort of conditions a two-wheeled urban warrior/commuter relishes. Read on for our full impressions and a video that will take you along for the ride.

Zero S Motorcycle

History and design

If you wanted the ideal man to form a company crafting purpose-built electric motorcycles, you'd be hard-pressed to find a better choice than Neal Saiki (sounds like psyche). He's a former NASA employee who went on to create some award-winning all-terrain bicycles (the Haro Werx 5/VL120) and trick components. He even was part of a team that created an entirely human-powered helicopter.

Ironic, then, that he's shifted his focus over to things that provide their own power -- alternative though it may be.

His company, Zero Motorcycles, started with rechargeable bikes intended for playing in the dirt, but its latest creation, the Zero S, is rather more of an all-rounder. It's a supermoto or motard, a breed of bike that slots in between a purely off-road dirtbike and a road-focused naked sportbike. While most in this class are little more than dirt models with fewer knobs on their tires and and more preload in the dampers, the S is a totally custom ride, sharing nothing with its trail-blazing predecessor.

Nothing, that is, except for incredible lightness. At just 225 pounds it is about 75 heavier than the Zero X dirtbike, but that's still a massive 75 pounds lighter than a comparable petrol-powered bike, like the 300 pound Yamaha WR250X. A quick look 'round the thing and it's plain to see why. Tap the frame and the aluminum feels thinner than the door panel on an econobox, but it's of course far more rigid and weighs a sprightly 29 pounds. Frame and sub-frame meet at a cylinder that bisects the structure and serves as the mounting point for the rear-suspension -- a trick job from Fox with a remote reservoir.

That shock is mounted to a similarly light and stiff (and also similarly bisected) swingarm, which provides nine-inches of travel on the rear. The front forks offer eight. Wheelbase is a lithe 55.75-inches, with 16-inch wheels on either end. Both sport disc brakes that look nothing if not lightweight; tiny and slender and perhaps better suited on a top-end mountainbike instead of a new-age motorcycle. But, they do the job.

It's all built around an 80 pound battery inserted where a typical bike's motor and radiator would go, sitting on a brushed aluminum tray with some die-cut flourishes on either side for strength and a little bit of style. Beneath that sits much of the electronics, cooled by a pair of small ducts on either side (plastic in this model, but they'll naturally be carbon fiber on the production bike). There were a few other differences here from what you'll see if you were to order one, the other primary one being the turn signals.

Those in the pictures are tiny, LED-infused, European-spec affairs, while the US Department of Transportation requires something rather larger -- and surely uglier. Regardless, it's a good looking bike for those who respect simple, minimalist engineering. Yes, anyone looking for aggressive styling like that found on the Suzuki B-King or Hayabusa will surely be disappointed, but even so there are a few things that could be improved. The tail section, for example, looks unnecessarily long, even if it's there to keep you from getting a line of gunge up your back, and the plastics on the front fairing ahead of the battery could use a little tidying up.

Like most great bikes the motor is fully exposed for you to gaze at appreciatively, but unlike most great bikes this one is so small it sits down between the pivot points for the rear swingarm, with a sprocket directly attached that turns the drive chain. A skilled mechanic can pull that motor in under two and a half minutes, and yanking the power cell doesn't take much longer. Why is that important? Saiki wanted to stress the upgradability of the bike: the battery is said to last five years, and while right now a new unit will set you back a massive $5,000 (half the cost of the bike), by the time you'll need one Neal hopes a replacement will have dropped to just $1,000 or less, and despite that will offer even more power. The same goes for the motor -- if you have more kilowatt-hours on tap you can pair that with a bigger motor for more power over the same range.

In other words: this is state of the art right now, but in a few years, when it isn't, you'll be able to easily swap the motor and battery for whatever the current hotness is. And, whether upgrading or just replacing that battery, it's important to note that it's largely salt based and contains no heavy metals. It can be thrown away in any landfill if you should desire and, believe it or not, it's edible. Well, the goop on the inside is, anyway.

The ride

Anyone who doesn't ride a scooter (or any of the disconcertingly growing number of automatic motorcycles) will feel a bit strange fondling a left grip with no clutch lever. Its omission makes starts and U-Turns somewhat jerky affairs, especially given the torque of the motor. It feels something like a newly introduced gas-powered bike with poorly sorted fuel injection, and much like the engineers of those bikes Saiki assures us things will be a bit more smooth on the production model.

The torque that makes starts a little shaky also makes the thing fun to ride. With just one mare over 30 horsepower it has the top-end oomph of your average 250cc buzzer, but with 62.5 ft/lbs of torque available from 0 RPM it gets up and goes like no little single or tiny inline twin could hope to. Sure, it lacks the rush that you get when your fire-powered econo-machine spins up north of 12,000 RPM, but most would trade that for twice the torque -- we know we certainly would. It was enough to zip us up to 50 mph (and stop again) well inside the span of a city block, and this was on a pre-production bike with about 25 percent less oomph than the ones customers will start receiving next month.

That said, some more top-end would certainly be nice. As it is maximum velocity is a paltry 60 mph, and while that's presumably limited to preserve motor and battery, if the Electric Motorsport GPR-S can go faster with far less power we'd like to see what the Zero S could really do with another gear. As it is this bike isn't really a safe on highways.

Many, of course, would argue that the thing isn't safe anywhere given the general lack of noise that it makes. It isn't totally silent, in fact it isn't much less noisy than a Kawasaki Ninja 250R at mild revs, but it's quiet enough that you can hear unexpected things, like the clashing of the chain and the subtle squeak of the brakes. It's a far cry from the average symphony (or drone, depending on your prerogative) of an average bike. Do loud pipes save lives? Saiki calls that an "absolute myth" and we agree; an inattentive motorist who doesn't see a motorcyclist isn't likely to hear them, especially since the Doppler effect means those rumbling pipes aren't doing much more than annoying those behind you -- and anyone within a few city blocks.

Suspension is on the soft side, very compliant over the potholes and creases we aimed for on this road, which should set this up to be very good for off-road duty. However, things didn't feel so soft that the bike wouldn't provide a clean, confident lines through faster turns. The brakes, however, don't give much confidence. The bike certainly stopped quickly enough, but without the immediate bite and responsiveness you'd expect on a lightweight like this. Looking again at the limited surface area on that front disc tells you why.

Wrap-up

By far the biggest drawback of this bike is its cost. At just shy of $10,000 it's nearly $4,000 more than a comparable 250cc supermoto, and while $.40 fill-ups from any 110 or 220 volt outlet sounds fantastic, given the 70+ mpg figures from the gas-powered competition in this class you'd have to drive hundreds of thousands of miles to make up the difference. Factor in reduced maintenance costs (no oil to change, coolant to flush, carbs to clean, valves to adjust, etc.) and that horizon gets a little closer, but the decision to buy one of these right now is not going to be based on economics.

You'll have to be the sort who wants to change the planet, be on the cutting edge of the future of transportation, or simply ride something that's different. Most of all you'll have to not want to go anywhere further than 60 miles round-trip, because that's as far you're going to get on a charge. Given the skinny, moto-style seat here you probably wouldn't want to sit on it for much longer than that anyhow.

It's a great bike, a real bike, and while it has more than a few shortcomings and a price that places it well into the "want" category and far from the "need," it's hugely fun to ride and, given that it makes no noise, legal to take to places where noise regulations would otherwise prohibit. Oh, and did we mention it's good for the environment? Yeah, that too.

Update: We're getting a couple questions in comments we wanted to address:

Q: What's the recharge time?
A: "Less than four hours" is the official line. We naturally didn't get a chance to find out just how much less.

Q: What's the seat height?
A: 35.5-inches, but the bike is so skinny so it doesn't feel that tall.

Q: What was the power delivery like?
A: A little like a bike with an ever so slightly loose chain; snatchy at first but totally usable. Throttle response was good at all speeds once moving.

Q: WHERE ARE YOUR GLOVES!?
A: Stupidly sitting right there on the curb, somehow forgotten until the shoot was over.

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