Yamaha is hitting the US market with a series of four pedal-assist electric bikes covering a range of urban commuting and light MTB riding. Powered by 250-watt, high torque mid drive multi-sensor motors and 500 Wh battery packs, the Urban Rush, Cross Connect, Cross Core and YDX Torc are in stores now.

The first three of these bikes use Yamaha's PWSeries SE motor, a fairly grunty 250 watt nominal system providing up to 70 Nm of torque, or approximately 280 percent of what you're doing at the pedals in its highest assist mode, through an efficient mid-drive unit that allows the motor to take advantage of the bike's gear train.

Pedal support is provided through the use of a three-sensor system that reads crank torque (how hard you're pushing the pedals), cadence (how fast you're turning the pedals) and rear wheel speed through high-speed sensors. That's significant, because it should help these motors do a great job of sensing what you're doing and contributing their power smoothly and intuitively, avoiding any jerky unexpected takeoffs and generally just giving you that "I've borrowed Lance Armstrong's legs" kind of feeling.

The trail-focused YDX Torc gets the beefed-up PW-X motor, which adds a further 10 Nm of peak torque to give a final output of 80 Nm, and 320 percent of your pedal effort in its highest EXPW assist mode.

For comparison, Bosch's high-torque Performance Line CX motor kicks in 75 Nm at its maximum, and that's one of the most powerful-feeling 250-watt nominal motors on the market. These new Yamahas will be no slouches. If they manage to avoid pedal drag above their maximum assist speed of 20 mph (32 km/h), they could take some business off Bosch.

Batteries are a reasonably unremarkable 500 watt-hours, at 36 volts. They're not integrated into the frames, which is disappointing, but they don't look too offensive as they sit, and the bottom mount point looks solid. It'll charge in around 4 hours.

Range figures aren't quoted, but we'd expect this kind of configuration to net you somewhere between 50 and 120 km (30-75 mi) of assisted riding, depending greatly on which mode you're in, your weight, the terrain, the tires, how windy it is and any number of other factors.

Urban Rush

The Urban Rush is an understated urban getabout with rigid forks and drop handlebars. It's got a 10-speed Shimano Tiagra groupset, complete with double chainring at the front, as well as 160 mm hydraulic disc brakes and an LED headlight that runs off the battery. It'll sell for US$3,299.

CrossConnect

The CrossConnect is your fully commuter-kitted road bike, complete with a rack, fenders and a pair of SR Suntour NCX 63mm air/coil forks up front to smooth out the road. The bars are flat, the grips ergonomic, there's a headlight and a side stand, as well as a 9-speed Shimano Sora trigger-shift gearset and 160 mm hydraulic disc brakes. It's going for $2,999.

CrossCore

The cheapest of the bunch at a retail price of $2,399, the CrossCore gives you basic rigid forks, a flat bar, ergonomic grips, a 9-speed Shimano Sora shift system, a headlight and the same 160 mm brake discs.

YDX Torc

The powerhouse of the lineup with its 80 Nm PW-X motor, the YDX-Torc is built for light MTB trail riding as well as road use. As such it gets a nicely curved, hydroformed frame, RockShox Recon RL lock-out forks with 120 mm of travel, and bigger 180 mm brake rotors. The shift system is upgraded as well, to an 11-speed Shimano SLX setup, and the tires are Maxxis Ardent 27.5 x 2.25-inchers with silkworm puncture protection under the tread. MSRP is $3,499.

All these bikes cut out their pedal assistance at 20 mph (32km/h), and will surely be available internationally in a Euro-spec 25 km/h limited model.

Yes, they're puny 250-watters, which won't impress many in US markets where much larger nominal wattages are road-legal. But that's just nominal power; anyone who's test-ridden a bunch of different 250 W bikes will tell you that it's the torque that counts, with some feeling vastly more powerful than others. We haven't tested any Yamaha mid-drives, but they're comparable on paper to the Bosch CX motors, which feel plenty fast and fun for urban use, so these should be worth a test ride.

Source: Yamaha

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