2015 Zero SR ZF12.5 +Power Tank | Review

2015 Zero SR ZF12.5 +Power Tank | Review
2015 Zero SR ZF12.5 +Power Tank

2015 Zero SR ZF12.5 +Power Tank – Test

2015 Zero SR ZF12.5 +Power Tank | Review
2015 Zero SR ZF12.5 +Power Tank

There is so much to like about the 2015 Zero SR ZF12.5 +Power Tank — once you get used to the missing two elements that have, thus far, been integral elements of the motorcycle riding experience. Sound, the underscore to almost every life experience, is completely changed on an electric bike, replaced by a whir that is quite pleasant and has many advantages.

Along with the various voices of an internal combustion engine, there is also the feel of the firing pistons that is simply not present on an electric bike. At first, something feels amiss, but it is surprising how quickly one can get used to this smooth near-silent experience.

This is a revolutionary year for Zero — it’s the first year Zero’s motorcycles have been built using only motorcycle componentry. As late as last year, Zero was still using a motorcycle/mountain-bike hybrid with a rear shock sourced from the pedal crowd. In 2015, we get the first true motorcycle from the Santa Cruz based company.

Sitting atop the Zero SR ZF12.5 +Power Tank, it feels similar to the Honda CB500F ABS, a friendly twin-cylinder upright sport bike. The two share identical wheelbases, the seat heights are within an inch, and the curb weights are separated by only 34 pounds — this Zero is heavier due to the long-range battery array.

Zero tucks in the rake an extra degree-and-a-half, while the two bikes have 17-inch wheels (a bit wider tires on the Honda) with a single 320mm front rotor and 240mm rear disc. So, the Zero SR ZF12.5 very much has the feel of a traditional motorcycle powered by internal com- bustion when it comes to size, weight, and ergonomics.

2015 Zero SR ZF12.5 +Power Tank | Review roadOf course, once the key is switched on and the Z-Force 75-7 passively air- cooled, radial flux permanent magnet, brushless motor is armed, the experience changes in a hurry.

The Zero SR ZF12.5 puts out 50-percent more horsepower and, more importantly, well nearly four times the torque of a CB500F. Those shocking numbers tell you one thing — the Zero performs.

It took a slight adjustment from my right hand to stop over-jumping my takeoffs. Without the pulsing engine under my fingers — which helps my mind moderate how I unleash it — I overcompensated by twisting too hard. Acceleration on the SR is immediate and impressive.

With plenty of torque from the bottom to the top, there is an ease of movement to everything the SR does. Even in the Eco profile, you don’t feel at all cheated by a lack of power. The SR is still lively and fun, though acceleration is not quite as instantaneous. On the freeway it tops out at 74 mph in Eco, and you won’t squeeze anymore out of it, even going downhill.

Toggling between the riding profiles on the fly using your right thumb makes this one of the most user-friendly mode switches, and encourages you to change things up just as often as conditions dictate.

When you’re feeling Sporty, it’s very easy to get going too fast; it is a reminder of how significant the sound of a revving engine is as an auditory guide and, when you don’t hear it, you continue to wind things up and wring it out. The Zero SF ZF12.5 can hit 100 mph in the Sport profile, and the bike feels plenty stable at high speed. It is worth noting that you can’t cruise at speeds over 85, as the motor will quickly heat up and reduce power—it happened to me.

The ABS-assisted J.Juan calipers provide adequate stopping power with a single 320mm disc up front, and a 240mm in the rear, and feedback at the front is very direct. However, considering how easily the bike accelerates and the minimal engine braking available, a second disc (or maybe a radially mounted Brembo caliper) would add a welcome sense of confidence when riding aggressively.

The SR’s Showa forks and new Showa motorcycle shock handle small bumps and pavement inconsistencies well at moderate speeds, but when pushing the pace in the canyons, the bike’s somewhat top-heavy figure makes itself known and can feel insecure over rough patches.

While Zero SR ZF12.5 has promoted to full Showa suspension, these are not the sort of high-end units you’d expect on a bike that has a recently reduced base price of $15,995 ($18,490, as tested). Although the 41mm inverted cartridge forks and piggy-reservoir shock have full adjust- ability, they do not compare with the Showa suspension found on the much less expensive Honda CBR1000RR, for instance. We would like to see a Zero SR with optional high-end suspension to go with its fine 23-pound aluminum twin-spar frame.

On favored smooth routes, however, the bike is surprisingly athletic and its willing acceleration almost demands a spirited pace. There’s something about riding at speed without the sound of the engine that makes you feel like you’re flying. The excellent Pirelli Diablo Rosso II tires help quite a bit, giving that confidence in corners that enhances that effortless feel.

2015 Zero SR ZF12.5 +Power Tank | testIt does take some acclimating, as the Zero SR ZF12.5 has a gliding sensation when coming off throttle due the lack of engine compression braking and the ability to downshift. This is perfectly fine in straight-line situations when there is no need to slow down quickly, but if I got into a turn too fast, instead of rolling off and letting compression braking slow me, I used a touch of the rear brake pedal for stability.

Around town the Zero SR ZF12.5 is a complete blast. The ease of operating a clutch- and shift-free transmission allows more attention on the ride instead of the operation, and the silent nature of the electric engine attracts totally different feedback from those around you.

Whether you are scooting through cars to the front of the queue at lights, or lane splitting through slow traffic, the Zero SR receives double takes and surprised looks—when it’s noticed. You can easily zip through quiet neighbors in stealth mode, attracting Zero attention.

It’s a fun feeling, as if you’re sneaking a ride where you shouldn’t. Even if you are noticed, without that ‘loud noisy motorcycle engine’, the Zero SR ZF12.5 is unlikely to rouse anyone’s ire.

The sporty but mostly upright ergonomics of the SR should be all-day comfortable, but you’ll run out of juice before you can truly test that, which brings us to the inescapable shortcoming of the Zero SR, even with the $2495, 44-pound +Power Tank option — the range is still not there, and it still takes too long to charge (10 hours with a standard plug to 95-per- cent; 2.3 hours with a $600 accessory fast charger).

Running on the freeway at rush hour, mixing high speeds and lane-splitting, the SR +PowerTank delivered about 100 miles from a full charge—well short of the claimed 125-mile range. I was most disappointed to find that I could not enjoy a spirited ride for the length of Mulholland Highway in the Santa Monica Mountains from the San Fernando Valley to the beach and back — a 61-mile round trip.

2015 Zero SR ZF12.5 +Power Tank | gaugeHard riding and hills are kryptonite to the battery and, long before I hit the turn-around point at Pacific Coast Highway, I had run through nearly half the charge and was forced put it in Eco mode and turn back.

Still, the 2015 Zero SR ZF12.5 +Power Tank can satisfy a variety of riding needs — from the perfect commuter bike, to an around town casual ride, to short-run canyon romper—and will be appreciated by experienced riders, even as it is docile enough for beginners. With routine maintenance unnecessary, and no trips to the gas station, it would be hard to go wrong with this as a second bike in your garage if the idea of electric power appeals.

Photography by Don Williams

Riding Style:

Story from Ultimate MotorCycling magazine; for subscription services, click here.

2015 Zero SR ZF12.5 +Power Tank Photo Gallery


  1. It should also be noted that there is no traction control on the Zero SR. If you pin the throttle in less than ideal traction conditions you will be very violently removed from the bike. Voice of experience talking here. Rode through some soft dirt before getting on pavement and obviously some of it stuck to the back tire. Ended up getting thrown about ten feet from the bike. On one of the adventure bike forums someone asked for suggestions for a hooligan bike and several people recommended the Zero SR. You can get really stupid on the SR without alerting half the country to your presence.

  2. With their severely limited range, long charge times, and insane pricing, electrics are hardly ready for prime time. Yes they are fast but so are jets, and we don’t put them on motorcycles.

  3. I have this bike – thought I’d add my two cents:
    First of all there is a typo in the article – he states that he coudn’t make a “61-mile round-trip”, right after stating the he was getting 100 miles/charge. Maybe he meant 61 miles each way? (You can easily ride a 100 mile round-trip).
    Secondly – the standard overnight charging does take a long time, but if you want to take a long ride and don’t mind bringing the optional off-board chargers along, you can charge up the battery pack at a car-charging station in the time it takes to stop for lunch. No, not as fast as getting gas, but much better than the prohibitive 10-hour charge time.
    I wouldn’t call the range, “severely limited”. I have ridden 150 miles on a single charge (riding at an average speed of 45 MPH in foothill twisties) – that’s a three hour ride – time to take a break no matter the type of motorcycle.
    Finally: the best analogy I’ve heard so far – from motorcycle reviewers – is that this technology is the closest we have on Earth to an actual “magic carpet ride”.
    That’s exactly what it feels like to ride this thing.


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