Brammo Empulse R vs. Zero S - Electric Motorcycle Comparison Test

Electric bikes come of age. If you could ignore the price, you'd buy one... really.

Hard Chargers: Brammo Empulse R vs. Zero S illustration
Brammo Empulse R vs. Zero S - Electric Motorcycle Comparison TestCycle World

Sure, we could have an intense political discussion about coal, ethanol, nuclear power and good old crude oil, but right now I’d rather ride motorcycles.

These two bikes, the Brammo Empulse R and Zero S, are just that: Motor. Cycles.

Last year, we were impressed by the Zero S (Road Test, 2012). It set a new benchmark for range and performance and became the first plug-in bike we'd tried that most enthusiasts could call a "real" motorcycle.

This pair blows that previous bike away. Power and range are up big time.

The Brammo has been much anticipated since it broke cover a few years ago, but it wasn’t until recently that production versions were available. In terms of components, riding position and feel, this is the most internal-combustion-motorcycle-like electric. It’s got 17-inch Marchesini wheels with sporty Avon AV 80 tires in 120/70 and 180/55 sizes. A fully adjustable 43mm Marzocchi fork and Sachs shock make for a decent ride, though the setup is overly stiff.

But the biggest similarity to the motorcycle you now ride is the Empulse’s clutch and six-speed transmission. On the surface, this seems like a great idea, but the clunky shifting and significant driveline lash (and the Zero’s great performance with a single speed) make it more like wasted effort.

During testing, I typically left the Empulse R in a single gear since the motor will pull reasonably well from a stop even in sixth (you never slip the clutch—it’s only for shifting).

2013 Zero S studio side view
Zero S * Killer 30–60-mph surge! * Super quiet * iPhone app makes for great charge-info/gauge interface * Please hire Massimo Tamburini for next design * Who will have the first good e-bike seat? * Components not up to snuff

The Zero, meanwhile, is magically, mystically quiet and smooth by comparison. Belt final drive is nearly noiseless and makes for lash-free riding. The Zero S is not as quick off the line as the Empulse R, but the California-made bike (Brammos are made in Oregon) is so much nicer to use that it doesn’t matter. Output from the two bikes is similar, both producing 50-odd horsepower on our Dynojet 250i dyno, with 62.6 foot-pounds of torque for the Brammo and 75.8 ft.-lb. for the Zero.

Taken on its own, the Zero’s styling and materials are decent enough, but to our eyes, it is not particularly attractive and looks and feels a bit toy-like when compared to the Brammo or other motorcycles. Its lower seat and compact dimensions make it more approachable to new(er) riders. Its seating position is less aggressive, too, and it is comfortable except for the saddle, which has a strange hump under the seemingly vanishing foam padding. Still, the Zero seat wins here by being less bad than the Brammo’s, which locks you into one place and hardly has any foam at all.

The single benefit that the Brammo derives from its multi-speed transmission is a stronger launch and quicker acceleration. Its 0–30-mph time is 1.61 seconds versus the Zero's 2.31, and the Empulse holds a time advantage all the way through the quarter-mile. In practical terms, though, the Zero feels snappy off the line, and midrange roll-on is phenomenal. The Zero really impresses when you whack the "throttle" (rheostat?) open between 30 and 60 mph. In fact, the S's roll-on acceleration times are amazing: 40–60 mph takes just 1.94 sec. and 60–80 only 2.68. That's better than a Suzuki Hayabusa's top-gear roll-on time, main difference being that the 'Busa will keep pulling sixth all the way to its electronically limited top speed of 186 mph.

At 65 mph, the Zero comes into its own and walks away from the Brammo until they meet again at 90 mph, where the Zero tops out. The Empulse creeps up to 103 mph.

Brammo Empulse R studio side view
Brammo Empulse R * Rides like a motorcycle * The cool kids want to be your friend * Charging-station ready * Gearbox makes little sense * Get Eric Bostrom to spec your suspension * Gauge-package range calculation varies so much it’s useless

The Brammo's big external charger and J1772 plug (common at public charging stations; visit to see a map) is mighty awkward to carry. The Zero uses a three-pole power cord like you might find on your desktop computer, with the unit on board. The cord fits easily in the zippered, soft-topped "tank" storage compartment. Both bikes take power from a standard 110-volt 15-amp circuit and need about eight hours to fully charge.

The big win for Zero here, though, is range. In “normal” use, half surface streets and half freeway cruising in the 70-mph range, the Zero made 60 miles with 15 percent charge remaining. As energy reserves got down to 25 percent, top speed began to be limited, and by that 15 percent, the Zero would only go 40 mph. The Brammo, meanwhile, never seemed to cut power even when showing just 3 percent charge remaining, but its range tended to be more like 40–45 miles in the same mixed riding. Perhaps the best information we can give you regarding range is this: On an identical 34-mile ride, the Zero’s gauge showed 37 percent of its charge left versus the Brammo’s 18 percent.

Where the Zero is most dissatisfying for the rider is in suspension and brake feel. Add to this a plasticky feel and unremarkable styling, and you find yourself blinking mightily at the price. The Brammo looks much cooler and has better components, but its suspension tuning and brake feel fall short of many streetbikes, particularly at this Ducati/BMW-level money.

Overall, though, electric-bike performance deficits have been largely overcome: These are fun, fast and interesting to ride. Range has been improved to the point that they’re genuinely useful for medium-distance commuting and around-town transportation. But price makes them mostly unattainable, or at least easily dismissible in the current marketplace.

Nonetheless, these two electrics prove the technology is there and that plug-in motorcycles will likely find a transportation niche. While we found the Brammo Empulse R in many ways more exciting to ride, its clunky transmission, bulky external charger and more limited range make it finish behind the Zero S. The latter is so smooth and quiet and easy to ride that it makes a case for the electric motorcycle.

|Brammo Empulse R|Zero S
DRY WEIGHT|471 lb.|393 lb.
WHEELBASE|56.9 in.|55.7 in.
SEAT HEIGHT|31.1 in.|30.5 in.
RANGE (AVG)|45 mi.|62 mi.
0-60 MPH|4.8 sec.|5.2 sec.
1/4 MILE|13.97 sec. @ 90.19 mph|14.01 sec. @ 89.65 mph
HORSEPOWER|52.4 @ 4900 rpm|56.0 @ 4665 rpm
TORQUE|62.6 ft.-lb. @ 1360 rpm|75.8 ft.-lb. @ 1088 rpm
TOP SPEED|103 mph|90 mph


Intro image

Brammo Empulse R - studio right-side view

2013 Zero S - studio right-side view

Zero's smartphone interface offers abundant information about the state of the charging system and more.

Smart phone app detail screen.

Group action shot.