BBS02B and BBSHD are not a setting

The BBS02B, model M315, is the smaller cadence motor: 750 W on the common listing, 100 Nm, about 4.3 kg, a 68 mm shell. A 500 W version is also sold. The BBSHD, M615, is the larger one: 1,000 W, 160 Nm, about 5.6 kg, often 48 or 52 V.

Both use the bike’s gears and both can be programmed. Programming does not make the hardware interchangeable. The chainring, the lockring and the controller live with the motor they shipped with.

Neither record is a British 250 W EAPC. A workshop can fit a limited controller. That fit is a new configuration, with its own continuous figure and its own cut-off, not a footnote on this page.

Budget a chain and a cassette into the first year if the bike will climb in a small gear. The motor will outlast a cheap chain without effort.