Bafang BBSHD 1000W: Power, Torque, Top Speed and Weight

Multiply them and you get peak electrical input. A 48V pack sits at 54.6V when full, and a 52V pack at 58.8V, so the numbers climb well past the label.

That is input, not output. Losses in the windings, the controller and the gearbox take their share, and they grow as the motor heats up. Voltage also sags under load, so a real climb sees less than the full-charge row.

• Seen as a 1500W motor? That is peak input rounded, with the same hardware and the same 30A controller.
• Seen as a 750W motor? Combined BBS02B/BBS-HD kits offer 500W and 750W options, and those are BBS02B motors, not the HD.
• Want more than 30A? That takes an aftermarket controller, covered in the controller guide.

In the US, the 1000W rating matters more than the peak. The Class 1–3 system most states use caps the motor at 750W, so a BBSHD bike is an off-road or private-land machine in most places.

Put a 42T ring against a 42T cog and the rear wheel sees roughly the crank torque. Drop to a 36T ring on the same cog and the wheel sees more, at a slower road speed. That is how a mid-drive hauls a loaded longtail up a grade that stalls a hub motor of similar rating.

The 160Nm is a claimed peak, and it arrives only while the controller lets the full 30A through. Lower the current limit in the software and torque falls with it.

• Low gears keep torque cheap. The motor makes its pull with less current, so it heats more slowly.
• High gears on a hill waste it. Cadence drops, current climbs to the limit and heat builds inside the case.
• Hard launches load the gearbox. The nylon primary gear takes the shock of every full-current start.

Riders who haul often pair the HD with a smaller chainring. Tooth counts and cassettes are covered in the chainring guide, and gear wear in the nylon gear guide.

Here is what a 27.5-inch wheel, roughly 2.2m around, does at two cadences. These figures are gearing maths; whether the motor can push you there depends on voltage, current, rider weight and wind.

Crank rpm is the figure people search for as "BBSHD rpm", and it rises with voltage. A motor's top speed scales with the voltage it sees, so a 52V pack spins roughly 8% faster than a 48V pack at the same load.

• Kits that list up to 45km/h or 37mph describe a fresh pack, tall gearing and no speed limit.
• The speed limit set in the controller cuts pedal assist; in some setups the throttle can be allowed past it.
• Tall gears raise top speed but slow every climb, so pick rings for the ride you do most.

For road use, the 28mph assisted limit of a US Class 3 bike is beside the point on a BBSHD, since the 1000W rating already puts it outside the classes in most states.

Add the battery and a complete conversion puts somewhere around 9–12kg on the bike, depending on pack size. A 52V 20Ah pack sits at the heavy end; a small 48V pack at the light end.

The dimensions that matter are the ones touching your frame. Measure these before you order:

1. Shell width. 68–73mm for the standard version, 100mm or 120mm for fat bikes.
2. Shell bore. Roughly 33.5–36mm inner diameter, threaded.
3. Down tube clearance. The motor body points forward under the down tube; a low tube, a cable guide or a kickstand plate can foul it.
4. Chainstay clearance. The chainring and its offset must clear the drive-side stay, which gets tight on fat bikes.
5. Ground clearance. The case sits lower than a normal crankset, so rocky trails and curbs find it.

Weight shows most when you lift the bike onto a rack or push it with the motor off. With the power on it disappears on climbs, and on descents the low mass keeps the bike planted.

Frame-by-frame fit is covered in the install guide, and wide shells in the fat-bike guide.

That design is simple and hard to break, and it suits riders who want the motor to do the work. It also explains the most common complaint: assist can feel like a switch, arriving with a surge and cutting a moment after you stop pedalling.

Programming softens it a great deal. These settings do most of the work:

• Start current sets how hard the first push is.
• Slow-start mode stretches the ramp from zero to full assist.
• Start degree decides how far the crank turns before assist begins.
• Stop delay shortens the run-on after you stop pedalling.
• Assist level spacing gives fine steps at the bottom for singletrack.

Those motors are compared head to head in the BBSHD vs Ultra guide. For most HD owners, the fix is an evening with the cable and the programming guide, which turns the on-off feel into something closer to a smooth ramp.

A throttle works alongside pedal assist on every version, and many riders use it to fill the gap at junctions where cadence assist is slow to react.