20 NOVEMBER 2015 // MOTORCYCLE CONSUMER NEWS
by Jeff Buchanan photos by Gina Cioli
IN WHAT COULD be perceived as a telling move concerning the future of electric motorcycles, Polaris (manufactur- ers of Victory and Indian Motorcycles) recently acquired
Brammo, the electric motorcycle company. Within months
of the acquisition, Victory entered a prototype electric race
machine in the prestigious Isle of Man TT and made headlines when they took third place against the highly developed Mugen Honda entries, and will now offer the bikes
for sale through its Victory dealerships.
Brammo Engineering will continue to develop the electric platform in partnership with Polaris, but the endeavor
is being presented solely under the Victory brand—the
only remnant of Brammo is their logo imprinted in the
rubber key fob and on the control levers. The new machine
is officially called the Victory Empulse TT.
The unique characteristics of an electric motor take a little getting used to. Because they can generate full power at
the first turn of the output shaft and are absent the sound that
accompanies a traditional gas engine, the sensation couldn’t
be more different. In fact, the instant power delivery from the
Empulse’s internal permanent magnet motor must be softened
by a controller to allow the power to come on more smoothly
with application of the throttle (by the way, “throttle” is actually
a misnomer, as it’s technically a rheostat).
The near soundless motion when riding the Empulse gives
the false impression of the machine being slow, when, in fact,
it’s reasonably quick, although not the quickest electric bike
in our experience. On the dyno, our Empulse produced 49.51
hp (in Sport mode) at the rear wheel, while both the prototype
H-D Livewire and the most recent Zero we tested, the 2014
ZF11.4, are clearly faster (the Zero giving 72.79 hp and 109.2
lb.-ft. of torque). In gas equivalent terms, you could say the
Empulse has the performance of a 450cc–500cc twin, and the
Zero and Livewire are closer to a 700cc.
When talking electric vehicle components, the battery is as
critical as the motor itself. Like the other electric bikes in our
limited experience, the Empulse uses a Lithium Ion battery
pack, the same type you find in laptops and consumer electronics, chosen for its good power density, meaning relatively
lighter weight. Drawbacks of the lithium ion design include
shorter recharge lives and greater degradation with age.
The engineer’s biggest challenge is to balance the size of
the battery (think fuel supply) against its weight, so the vehicle
doesn’t become too heavy. In the Empulse’s case, the battery
provides 103.6 Volts in Eco Ride mode and 117.6 Volts in Sport
mode. The difference in power feel between the two settings
is minimal, but the Sport setting will clearly drain the battery
faster if you use full throttle for any length of time.
Victory says the battery is good for the life of the bike,
2000 recharge cycles, and it backs this assertion with a 5-year,
100,000-mile warranty on the battery. However, as of this print-
ing, no battery replacement costs had been finalized. And as
this technology is so unfamilar to most of us, it needs to be
mentioned that batteries don’t return to the exact same power
level with each recharge, but actually drop slightly each time.
A big part of dealing with electrics is managing battery
usage, which means constantly monitoring the battery’s energy
consumption gauge. As you do, you quickly see that changes
in riding style will dramatically alter the estimated range. On a
full charge and riding sedately, our Empulse showed a predicted
range of 134 miles. Yet when we ran higher speeds and asked
for stronger acceleration, the range estimate dropped rapidly
to just 70 miles.
Determined to test its real world range, we rode a local route
with a variety of traffic conditions at a variety of speeds. Starting with 100% charge, our Empulse was good for just 66 miles
(for reference, the Zero SR, Sept. 2014, went 98.7 miles). And
when your battery gets low, it’s not merely a matter of looking
for a gas station, you need the charger, an outlet, and plenty
of time. Plugged into a 110 V outlet, our bike needed just shy
of eight hours to replenish the battery to 100% while drawing between 12–14 amps. However, there is a 240 V charging
option available that claims recharging an empty battery to
95% in 3. 5 hours. But there is a bigger difference between 95%
charge and 100% charge than you might imagine.
Transmission & Clutch
The Empulse is also unique in the category for being fitted
with a motorcycle-like constant mesh six-speed gearbox rather
than simply a single-speed direct drive.
While shifting helps to make the Empulse feel more like a
traditonal motorcycle, given the constant power of an electric
motor, does the changing of gears and repeated building of revs
produce better acceleration, or is the advantage more imaginary
than real? Although the engine is capable of handling starts in
any gear, shifting into first for take-offs does provide the stron-gest acceleration, and is also said to improve the regenerative
braking effect. But a serious drawback is that the transmission
contributes to the Empulse’s excessive drivetrain lash, which
is especially disconcerting when getting back into the throttle after letting off, when full torque happens instantly. One
wonders if the benefits of a transmission are worth it, or if it
would be more advantageous to lose the weight and let the