2014 Zero SR | FIRST RIDE

As** electric motorcycles** continue their march toward credibility, it has to be said that Zero is leading the charge, so to speak. Each iteration of this company's products gains performance, capability, range, and value. This year will not be the exception, thanks to the 2014 Zero SR, an upgrade to the existing Zero S. It's fitted with a 33-percent-larger, 660-amp Sevcon Size Six controller—engineered by Zero but made in China. This controller allows the brushless Z-Force motor to produce a claimed 106 pound-feet of torque and 67 hp, increases over the Zero S of 56 and 24 percent, respectively.

More power is always better. In this case, Zero claims a 0-to-60 time of 3.6 seconds and a top speed of 102 mph. Usually power and range are at odds with each other but not here—not this time. As is usually the case, improvements come on many fronts. Each update of the air-cooled, direct-drive motor and controller has brought efficiency gains —that brings the extra power. But the most direct way to improve an electric bike's range is to give it more energy to begin with. And that's part of what Zero's done with the new SR. In addition to the SR's standard 11.4 kilowatt-hour battery pack, there is also an option called a Power Tank. This $2,495 add-on brings total maximum capacity to 14.2 kWh. (Incidentally, any 2014 Zero S or DS can be fitted with this 2.8-kWh auxiliary battery pack for the same $2,495.) Claimed curb weight goes from 407 pounds to 452 with the Power Tank.

What does this extra capacity do for range? According to Zero, the SR with the Power Tank option has a maximum range of 171 miles in city use, compared to 137 miles on the base battery pack. That's impressive, but it's also the best case, with the bike taking advantage of low speeds in the city cycle and plenty of regenerative braking. If you can keep your wrist out of it and maintain a steady 55 mph on the highway, the SR will go 106 miles, or 131 miles "combined," which simply means half at 55 mph and half in the city. Up the highway speed to 70 mph and you'll be pushing after 88 miles, says Zero, or after 116 miles of combined highway/city use. It's worth noting that the 102-mph top speed is peak; the bike is rated for 85 mph maximum sustained.

Also new for 2014 from Zero is a five-year/100,000-mile warranty covering the motor and controller (on all Zero models). Further, the company estimates that the SR's basic battery pack will live to see more than 300,000 miles in typical use and a massive 385,000 miles when combined with the Power Tank. Using the on-board 1.3-kW charger, the batteries (including the Power Tank) can be recharged from empty to 95 percent charge in 7.4 hours. But by using the optional CHAdeMO fast charger ($1,800), recovery time is just a little over an hour.

Beyond the controller and battery pack, though, the Zero SR is familiar material. The twin-spar frame introduced for 2013 is unchanged from before, but the entire 2014 Zero lineup gets improved Fastace suspension, with a beefier 43mm fork (up from 38mm) and wider triple clamps, plus a completely reworked and now fully adjustable rear shock. This chassis is wrapped in more refined styling by designer Matt Bentley, and you'll enjoy a far more informative LCD dash. Using new switchgear, the rider can now toggle among three riding modes: Eco, Sport, or Custom. The Custom profile is user-determined through an iPhone or Android device connected via Bluetooth.

The 2013 Zero S already offered a big step up in performance and allure from the firm's previous products, but the SR is another leap forward. With direct drive and a motor that intrinsically makes torque anywhere, it's so incredibly easy to get off the mark, though in Sport mode (because of the extra torque) you'll find it hard to do so without a jerk as you start forward motion. This brusque pickup requires a subtle change to your riding technique even over the stock 2014 DS, let alone previous less-torquey Zero models.

In urban mode, the SR is just as easy and controllable to ride as any less potent an eBike, especially since you don't have to worry about working the clutch lever to coax the motor into delivering drive. In Eco mode especially, it's very docile and usable, just whizzing silently through city streets where you'll want to pay special attention to pedestrians stepping off the curb in front of you because they hadn't heard you coming. Should you decide to treat the SR like a small, silent sportbike, you'll appreciate the upgraded suspension, which reflects Fastace's and Zero's continuous development. Gone is the bike's tendency to bounce and clang over big bumps; both ends are better, but the shock dramatically so.

There's little doubt the Zero line has improved substantially every year, and the models are gaining in value. The upgraded SR, at $16,995, is $1,000 more expensive than last year's Zero S with the same battery capacity, though the returning S is now $1,000 cheaper. An SR with the Power Tank nudges $20K. As ever, the seemingly high MSRP has to be balanced against the SR's simplicity, potential for longevity, and the estimated $1.60 in electricity costs it takes to "fill" it.

An evolution of the heavily updated 2014 Zero S, the SR offers more power, quicker acceleration, and a higher top speed.

Brammo Empulse LE

With more performance and better range, the Zero becomes an ever more compelling transportation device.