bbshd shutting off

[ebikeer]

I have the luna cycles giant bike with the bbshd motor. So the problem is when hitting a dip or pothole at speed the motor shuts off for about 2 seconds then back on as nothing ever happened. I should also point out that the display is not affected by this. All the electrical connections look to be tight and im not sure were to go from here.

[funwithbikes]

hmmm. Do you have sensors on your e-brakes. A sharp bound might be enough to bring the magnet and sensor close enough to tell the motor to shut off because it thinks the brakes have been squeezed.

Could you try disconnecting the brake sensors and seeing if the problem still happens?

[ebikeer]

I do not have brake sensors.

[ebikeer]

Is it normal this quiet in here?

[mbwaterdog]

Does it have a gear shift sensor? Maybe that is getting jolted somehow?

[ebikeer]

would that still be a problem using while the throttle only?

[mbwaterdog]

Definitely. I throttle and shift all the time. The gear sensor shuts off the motor when throttling or I PAS. I can't imagine the cable shifting without you actually shifting gears, but what I'm thinking it could be is the actually gear sensor itself moving. It might be getting bumped somehow. For example, if your bike is full suspension, hitting a bump might cause the gear sensor to move over the cable, thereby cutting your motor out. It could also be that the connection between the sensor and your controller is loose. I would check that (and ebrake sensors, but you don't have those) first, then troubleshoot from there. The gear sensor is normally seated in the cable housing, which should prevent this problem found happening, but you never know. Of course, always double check connections.

[Woody]

You could disconnect the gear sensor cable at the wiring harness and take it for a test ride to see if it still cuts out on the bumps. But without brake sensors the only way to shift safely would be to stop pedaling for a second while shifting. If it cuts off on the bumps while pedaling or using throttle then at least you know it's not the gear sensor.

[ebikeer]

I do have a full suspension bike. I checked the wiring connection for the gear sensor it looked tight. I then disconnected the gear sensor from the wiring and then went three miles fast and hard over rough terrain with no problems. Before I did any of this I noticed the shift cable housing might be moving at the zip ties near the derailleur.

[lairpost]

I experience the same problem, also a full suspension with gear sensor. Have you found a solution that will allow running the gear sensor without the motor cutoff issue? I thought about better securing the cable housing to the swingarm as I expect that housing is moving with the suspension action, not the shifter cable.

[mbwaterdog]

You could try mounting the gear sensor on the chain stay - drive side - near the derailleur. Run the cable along the stay to the motor. Of course, best to make sure the problem is the cable housing moving, causing the sensor to slide over the cable thereby causing a 'false' motor cutoff signal. Another way to test this theory is to try riding on flat level ground, or locking out your suspension. If that solves the problem, then it likely is the cable housing moving and the next step should be to either (1) secure it better, or (2) move it. I can't imagine the cable housing moving the sensor unless yhe housing was cut sightly short and there is a small space inside the gear sensor for it to move around.

[tom e gun]

I have a problem, my motor and dispay shut off and won't come back on for 5 to 10 or 15 min, then I can ride a quarter mile or so and it shuts off again, has any one had this problem ?

[AZguy]

I had a similar problem with a BBSHD that turned out to be a connector between the battery and motor that arced and was no longer making a dependable connection. Bending the male pins back to being more flared helped but I ended up replacing the connector anyway.

[max_volt]

https://electricbike.com/forum/forum/knowledge-base/motors-and-kits/bbshd/39217-troubleshooting-a-completely-dead-bbshd-or-bbs02

[tom e gun]

Well I took the connector off and rard wired it using crimp connectors and rode it one day without any problems then yesterday I rode it and it seamed fine at first then I hid a bump and it shut down on me again, and did some weird stuff with my display, changed my settings, cleared my odometer an things like that, anyway today I took it apart again checked the battery voltage with a meter at the battery and at the wires coming off of the cradle, that seamed fine, I use crimp connectors and wired in a st 90 connector and turned it on, well lifting the back wheel and giving it throttle I only get 15 mph full throttle and flashing red dotted line where it say pow on my display ? Any help would be appreciated.

[JPLabs]

It sounds like it's struggling to provide much current. Anytime bumps change things, you can be 99% sure you have a connection issue, someplace. Hopefully not inside your battery pack...

Inspect and wiggle more wiring, maybe hang the bike, have someone else hold throttle, while you use both hands to inspect. Note I didn't suggest using a rubber band on the throttle, that would be dangerous. ;)