While rivals Mission and Brammo have either completely disappeared or been swallowed up by a larger company, Zero keeps improving and introducing new bikes. It's steadily improved its offerings over its 10-year history. I rode the DS model a few years and wasn't impressed. It felt like a bad motorcycle with an electric motor strapped on. A few months back I rode the 2015 DS, FX and SR models and was impressed at how much the company had come at creating vehicles that were not only real motorcycles, but were fun to ride.

The new DSR has 25 percent more horsepower and 56 percent more torque than the regular DS. That performance increase is due to the new high-output 660-amp motor controller. The base model ($15,995) has a city range of 147 miles and freeway range of 70 miles when cruising at 70-miles an hour. The optional "Power Tank" adds 2.8 kWh of power storage (for an additional $2,674) that extends the range to 179 miles in the city and 86 on the highway.

The FXS continues the FX's mission to make riding on the street way more fun than it should be. It has 70 pounds of toque and up to 44 horsepower in a less-than-a-300-pound body. The 3.3 kWh version with 45 mile city range runs $8,495 while the 6.5 kWh version with a 90 mile city range will set you back $10,990.

The motorcycles are both powered by the updated Z-Force motor. Zero says the motor produces power more efficiently, cools more rapidly and has a higher thermal capability. Basically, it lets you ride the bike harder and at higher sustained speeds with better range. In addition to the new bikes, the motor will be in the 2016 Zero SR, Zero S ZF13.0 and Zero DS ZF13.0.

Zero is also introducing an industry standard (J1772) charging port in its new Charge Tank accessory. It's the same charging port system used by Tesla and the Fiat 500e. This is in addition to charging via a regular wall outlet. Known industry wide as Level 2 charging, the new tank will speed up charging from up to over eight hours to about two or three depending on the bike. The Charge Tank will be available in the spring for an additional $1,988 and will work with 2015 and later SR, DS, DSR and S models.

All these new bikes will be available in dealerships starting in November.