If you mostly ride off-road, want a throttle-heavy bike and like to tune things yourself, the Bafang BBSHD is still hard to beat for the money. If you want pedaling that feels natural, a 750W rating for street builds, or a 60V or 72V battery, the CYC Photon Gen 2 is the better fit. Both bolt into a standard bottom bracket and drive through your bike's gears. They just feel very different once you're riding.

The two kits side by side

These figures are from our product listings at the time of writing.

How they feel to ride

This is the biggest difference, and the spec table doesn't really show it.

The BBSHD uses cadence-based pedal assist. Once the cranks start turning, the motor gives you the power set for that assist level, whether you're pushing hard or just spinning your legs. A lot of riders like that. It's simple and strong, and with the throttle it pulls hard from a stop. The tradeoff is that it can feel like the bike is riding you, especially on tight trails or at low speed.

The Photon Gen 2 uses torque sensing. The harder you push the pedals, the more help you get, and when you ease off to shift, the motor eases off too. That's why a shift sensor usually isn't needed on a Photon. It feels much closer to a regular bike with stronger legs. If you've ridden a modern factory e-MTB and liked it, this is the one that will feel familiar.

If someone tells us "I want torque sensing," the answer is the Photon. There's no setting that makes a BBSHD feel like a torque-sensing motor.

Power, legality and where you'll ride

The BBSHD is a 1000W motor. Most US states cap e-bikes at 750W, so we sell it for off-road and private land use. If your build has to stay street legal, the Bafang BBS02B is Bafang's 750W option.

The Photon Gen 2 is rated at 750W with a 1200W peak, and a 250W version is available on request for places with stricter limits. It also has an unrestricted off-road mode that goes up to 2000W. Check your local rules before you turn it on.

Battery voltage

This one catches people out. The BBSHD runs on 48V or 52V only, and the battery should be able to supply 30A. Don't put a 60V or 72V pack on it. If you're running a 52V pack and see Error 07 or Error 30, our guide to flashing the Bafang controller explains the fix.

The Photon Gen 2 accepts 36V up to 72V, so it works with most packs you might already own. A higher-voltage pack gives you more speed headroom. The battery still has to keep up, though. We've seen cheap packs with weak BMS boards cut out when the Photon was set to maximum power, and lowering the power and torque settings fixed it. Our e-bike battery guide covers how to match a pack to a motor.

Fitting it to your frame

Both kits come in versions sized by bottom bracket shell width, so measure yours before you order.

• BBSHD: 68-73mm for standard mountain and hybrid frames, 74-100mm for most fat bikes, and 101-120mm for extra-wide fat bike shells. Press-fit frames need an adapter, such as the Lekkie BB86/92 adapter.
• Photon Gen 2: versions for 68-83mm, 100mm and 120mm threaded BSA shells, plus a BB92 press-fit version, so BB92 frames are covered without a separate adapter.

Chainline is worth a look on either kit. On the BBSHD, a lot of riders add an offset ring like the Lekkie Bling Ring to straighten the chain. Our Bafang chainline and Q-factor guide covers it. On the Photon, the spacer and chainline numbers for each shell size are in the Photon Gen 2 Q factor and chainline table. Chainring options run from 32T to 50T.

Full-suspension frames are the one place we'd slow down. Don't assume a motor fits from the frame model name alone. Send us photos of the bottom bracket area and the linkage first, and we'll check clearance with you.

Tuning and displays

The BBSHD UART is the tinkerer's motor. With a UART programming cable you can change current limits, assist levels and throttle behavior yourself, and there's a big community sharing settings. Our Bafang programming guide walks through it. The EggRider V2 lets you tune from your phone instead. Bafang also makes a CAN bus BBSHD. On CAN you can only change a few things (wheel size, speed limit and assist), and UART and CAN parts don't mix.

The Photon Gen 2 comes with a display (SW102T or the colour Intuition), and settings are handled in the display and CYC's Ride Control app. You get fewer settings to change than on a UART Bafang, and the defaults suit most riders. Our Intuition display guide covers setup.

Cost

On price alone, the BBSHD is cheaper: $679.99 for the kit, plus a display, which is sold separately. The 860C is about $105. The Photon Gen 2 starts at $949.99 and includes the display, throttle and speed sensor. Add the 860C to the BBSHD and you're at $784.98, so the gap to the Photon is about $165 for a threaded frame and about $223 for BB92. Prices change, so check the product pages for current numbers.

Parts and service matter too. BBSHD parts are cheap and easy to find. The Photon Gen 2 is modular, so the controller and other pieces can be swapped without replacing the whole motor.

So which one?

Pick the BBSHD if:

• the bike is mainly for trails, sand, snow or private land
• you like riding on the throttle and want full power with little pedaling
• you already have a 48V or 52V battery
• you want to tune every setting yourself

Pick the Photon Gen 2 if:

• you want assist that responds to how hard you pedal
• the bike needs to stay at 750W, or at 250W where that's the rule
• you want to run a 60V or 72V battery
• your frame has a BB92 shell
• you'd rather have the display and throttle in the box

Still stuck? Send us your bike, your bottom bracket width, your battery and how you ride, and we'll tell you which one we'd put on it.

FAQ

Is the CYC Photon Gen 2 more powerful than the BBSHD?

On paper, the BBSHD is rated higher (1000W vs 750W) and lists more torque (160 Nm vs 135 Nm). The Photon Gen 2 peaks at 1200W, or up to 2000W in its unrestricted off-road mode. In practice, the Photon's torque sensing makes the power feel smoother, while the BBSHD feels punchier on the throttle.

Can I run a 72V battery on a BBSHD?

No. The BBSHD is a 48V or 52V motor. If you want 72V on a mid-drive, look at the Photon Gen 2 or the other CYC kits.

Does the BBSHD have a torque sensor?

No. The BBSHD uses cadence-based pedal assist plus a throttle. If torque sensing matters to you, go with the Photon Gen 2.

Do I need a shift sensor?

On a BBSHD, many riders add one so the motor cuts power while they shift. On the Photon Gen 2, you usually don't need one, because the torque sensor backs off when you ease off the pedals.

Will either kit work on a fat bike?

Yes. The BBSHD comes in 74-100mm and 101-120mm versions, and the Photon Gen 2 has 100mm and 120mm BSA versions. Measure your shell width first.