The November 2013 issue of Cycle World magazine has (starting on page 52) a direct instrumented comparison of the $18,995 2013 Brammo Empulse R and the $15,995 2013 Zero S. The “shoot out†article, written by Mark Hoyer, was very interesting and contained some comments that I had not expected.
In particular, he didn't think too much of the Empulse's transmission and felt that it was mostly there to make the bike more like a conventional IC motorcycle. While it did improve the Empulse's acceleration from a stop and likely improved it's top speed, Mr. Hoyer said that it had clunky shifting and significant drive-line lash, making it more like wasted effort than a real advantage in normal riding. He said that he typically left the bike in one gear and never bothered using the transmission. In contrast, he said that the Zero “is magically, mystically quiet and smooth by comparison. Belt final drive is nearly noiseless and makes for lash-free riding.†Mr. Hoyer goes on to say that the Zero S is not as quick off the line, but it is so much nicer to use that it doesn't matter.
The Zero's roll-on acceleration, between 40-60 mph is 1.94 seconds and between 60-80 mph is only 2.68 seconds, both times are faster than a Suzuki Hayabusa's top gear times. However the Empulse's 103 mph top speed bested the Zero's top speed of 90 mph.
Both bikes were said to have poor seats, with the Zero's being slightly better than the Empulse's. Also, the Zero was said to have a better riding position that the Empulse. However, the Empulse had a better chassis, better suspension components, wheels and tires and looked like it was worth its purchase price more than the plasticly Zero. The Zero was also let down by its poor brakes and suspension.
Here are the ups and downs: The Zero got ups for its “killer 30-60 mph surgeâ€, being super quiet and its IPhone app makes for great charge-info/gauge interface. It's downs included its poor styling, poor seat and poor components (for the purchase price). The Empulse got ups for riding like a motorcycle, looking cool and being charging-station ready. It's negatives included “gearbox makes little senseâ€, poor suspension set-up (too hard) and “gauge-package range calculation varies so much it's uselessâ€.
Here are the measured hard numbers:
Brammo Empulse R: weight: 471 pounds, range: 45 miles, 0-60 mph: 4.8 seconds, ¼ mile: 13.97 seconds @ 90.19 mph, horsepower (measured on a Dynojet dyno): 52.4 @ 4,900 rpm, torque: 62.6 ft-lb @ 1360, top speed: 103 mph.
Zero S: weight: 393 pounds, range 62 miles, 0-60 mph: 5.2 seconds, ¼ mile: 14.01 seconds @ 89.65 mph, horsepower: 56.0 @ 4665 rpm, torque: 75.8 ft-lb @ 1088 rpm and top speed: 90 mph.
The Zero was given a “big win†in the range department. In “normal†use, half surface streets and half freeway cruising in the 70-mph range, the Zero would travel 60 miles with a 15% charge remaining. However, as the charge dropped to 25%, top speed also began to drop, and by 15% charge, the Zero's top speed was limited to 40 mph. On the other hand, the Brammo would run at full performance levels, even when its charge level was only 3%, but its range tended to be 40 to 45 miles under “normal†use. On an identical 34-mile ride, the Zero's gauge showed 37% of its charge left, vs the Empulse' 18%.
The article comments that electric motorcycle performance deficits have been largely overcome and they are fun, fast and interesting to ride. But price remains an issue in the current marketplace, although plug-in motorcycles will likely find a transportation niche.
It concludes with the following statements: “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.â€