Powering the Grinder is the 255W Fazua Evation Black Pepper motor, a unique power plant that’s lightweight and fully removable from the bike.
A 36V, 7Ah (252W) battery is also housed inside the removable drivepack and sits just on top of the motor. It’s not the largest battery, but it pairs nicely with the 255Wh motor. The motor and battery combo couples with a mechanical gear box in the bottom bracket that transfers power through the cranks and into the rear wheel. Should you choose to ride the Grinder as a non-motorized traditional bike, this entire drivepack is removable and can be replaced with a hollow shroud — a swap that makes the bike about 8 lbs lighter.
I’m a really big fan of this motor. This is the second BULLS bike I’ve ridden and reviewed with the Fazua system, and I love how stealthy it looks and how well it matches your natural pedaling. As I mentioned before, I like e-bikes that make you forget they have a motor. The Fazua does this very, very well.
BULLS built the Grinder as a member of the budding family of “super light” e-bikes, which employ smaller motors and batteries in a drive system designed to emphasize fitness, ride quality and stealthy looks. The e-bike portion of the bike is designed to supplement a rider’s pedaling instead of overpower them. To accomplish this, they took a less is more approach to the motor and battery, allowing them to conserve weight and achieve a very natural ride feel.
The Grinder is a Class 1 e-bike with pedal assistance to 20 mph. Fazua motors have three pedal assist settings starting at “breeze,” or the lowest power setting with 100W of aid, then “river” or the mid-power setting with 210W of assistance and “rocket,” the 250W highest power setting.
The “river” mode was my happy place — It’s where I spent most of my time on flat roads and small-ish hills, though I did find myself toggling up to “rocket” mode on steep or long hills and I’d frequently drop down to “breeze” to conserve battery on downhills or pancake-flat sections. Despite its emphasis on fitness and a rider’s pedaling, it’s incredible just how much power this bike has. On steep hills, the “rocket” mode is aptly named; there were few steeps this bike couldn’t fly over.
Like BULLS’ other lightweight e-bike the Alpine Hawk, the Grinder is lacking a handlebar display or touchpad. Instead, the bike uses a remote discreetly mounted on the downtube.
This remote has five LED lights that show battery life and change color depending on your chosen pedal assist level. There’s just one button in the center to turn the bike on and off, and touch-sensitive pads on the top and bottom of the remote allow you to cycle through the assist settings. This ultra-discreet display is another testament that the Grinder is a bicycle first and e-bike second. Sure, the lack of display and slightly hidden remote took a little getting used to, but I appreciated not having the handlebars cluttered with a big display and some buttons.
