Zero Motorcycles continues to upgrade its model line-up, with the 2013 Zero Motorcycles bikes getting a motor and battery upgrade. Offering bikes now in 8.5 & 11.4 kWh packages, Zero claims city mileage ranges to be 103 & 137 miles, respectively. The motors on the Zero S, Zero DS, and Zero MX have been bumped up to 54hp spec, the Zero XU retains its 27/28hp configuration, and the new Zero FX gets a 44hp lump.

The big addition to the family is the 2013 Zero FX (pictured above), which follows the lines of the Zero DS dual-sport, but uses the same chassis as found on the MX. The Zero FX appears to be the more off-road capable version of the Zero DS. While the DS will have 8.5 & 11.4 kWh options for its battery packs, the Zero FX will come with only 2.8 & 5.7 kWh unit options — the same as the Zero XU and Zero MX. Pricing on the Zero FX starts at $9,495.

The added battery and power boosts should help keep Zero Motorcycles in check with Brammo, which is set to finally bring its Brammo Empulse R street bike to market later this year. With 2013 rumored to have a “Brammo Killer” in the line-up, we’re not quite sure if the Zero S design lives up to the hype, even with its upgraded power train, but considering the sales figures between the two companies, we might be wrong on that assessment. Photos after the jump.