Does the Bafang M510 decouple when it hits the speed limit?

[b3nnyh]

Does the m510 bafang motor decouple when it hits its speed limit?

@Greg Watts

 

[Greg Watts]

Good question, and one that comes up a lot with the M510 because the answer affects how the bike feels when you're pedalling above the assist cutoff.

Short answer: yes, effectively. The M510 has very low pedalling resistance above the speed limit. It's one of the motors people single out as feeling close to an analogue bike once you're over the cutoff, which is why it's popular for lighter, more natural-feeling builds. There's no hard mechanical clutch decoupling like some hub setups, but the internal drag is low enough that you don't feel like you're dragging an anchor up to road speed.

A few things worth knowing while you're here:

The speed limit itself is stored in the motor firmware, not the display or controller, so it's set once and stays put. Factory limits vary depending on where the bike was sold — EU bikes are pegged at 25km/h, but @temon10 noted the M510 3.0 ships from the factory with a 45km/h limit in some markets. @Rosz had a Berria Mako HP6 set to 27km/h on FC 2.0 firmware, so there's some variation.

If you want to change it, @vikino1 reckons Bafang's speed unlock is genuinely easier than other manufacturers — no dongles taped to the chainstay, no magnet trickery. You use the BESST tool or the Go+ app to flash the limit, though as @Nuggets pointed out the app can only set up to whatever the firmware allows. Buy it unlocked from the start if that matters to you.

One gotcha: @ficorama had a speed sensor magnet sitting too close to the sensor, which caused the motor to cut out at low speeds because it thought he was doing 58km/h. Worth knowing if your cutoff feels weirdly aggressive.

Happy to dig into firmware versions, the BESST tool, or how the M510 compares to the M560 if you're weighing options.

 

[Zimmerframe]

Does the m510 bafang motor decouple when it hits its speed limit?

@Greg Watts

No, well, sort of, the clutch isn't engaged.

Resistance when the assistance cuts is similar to most other motors, ie, negligible - most of the resistance you feel is tyres, weight and the sudden change from being helped to not being helped.

You can still push on though, I was regularly hitting 46kph yesterday on the flats (wind behind).

Most annoying M510 thing is the assistance cuts at about 120 cadence, so if you're climbing hard in a lower gear you need to learn to adjust your gear choice so you don't suddenly lose assistance when you most need it.

 

[b3nnyh]

No, well, sort of, the clutch isn't engaged.

Resistance when the assistance cuts is similar to most other motors, ie, negligible - most of the resistance you feel is tyres, weight and the sudden change from being helped to not being helped.

You can still push on though, I was regularly hitting 46kph yesterday on the flats (wind behind).

Most annoying M510 thing is the assistance cuts at about 120 cadence, so if you're climbing hard in a lower gear you need to learn to adjust your gear choice so you don't suddenly lose assistance when you most need it.

Thanks Zimmerframe, that's good to know there's an actual clutch that disengages, I'm a little inexperienced when it comes to emtbs, I'm still on analogue, but looking into emtb (n+1), I ride with friends on emtbs, they are faster on the flats and up hill, but I tend to be faster downhill. I don't want to get hindered by a motor cut out. Generally I guess there's not much pedalling on downhill trails so probably was a dumb question.
I'm thinking of SZZS cef69 XL and a m510 to stay within my local 250w limit.

Thanks again for a real world experience reply.