Do I really need motor cut brake levers?

I replaced the brakes and rotors on my Bafang Max drive bike. However the Bafang levers do not have enough pull for my new Avid BB7 calipers.

My idea was to get some proper Avid FR7 levers I know will work. So do I really need motor cuts outs?

Or does anyone know who makes a proper mountain bike lever with motor cut?
 

harryS

Well-Known Member
Motor cut-outs are a user decision, but I think they are necessary.

They do sell brake sensors you can mount in the middle of a brake cable. There are also sensors you can mount on hydraulic brake mechanisms too.

Here's a cable sensor on ebay that would need some cable splicing skills.

(Link Removed - No Longer Exists) that fits Bafang connectors.
 
Motor cut outs are not strictly a user decision. Some states coast to coast have laws requiring motor cut outs when the brakes are activated.

Georgia law for example states, "The electric bike may not exceed 20mph and must disengage the engine when the brakes are applied."

In California the law reads, "Electric bikes motors must disengage when brake functions are applied and use a switch or mechanism that, when released, will cause motor function to cease."
 

eDean

Active Member
My boshe fs rx does not have a motor cutout and I never miss it. I did not even know it didn't have that feature until after I owned it for a year. The breaks are so much more powerful than the motor.
 

opimax

Well-Known Member
I would think they are needed most when stopped , preventing the motor form engaging when not expected....bumping the pedals or the throttle by mistake
 
Can the break plugs on the controller be shorted out ? That could be my problem.
I'm all hooked up correctly and get nothing when I twist the throttle.



Charlie
WA4TWA
 

Green Machine

New Member
hell no.... go without them.

Just make sure your brakes are strong enough to stop the bike if it does happen to get stuck in wide open throttle....by the way i have never heard of this happening ...not once....
 

jusio

New Member
I have a bike with Bafang Max as well, and I don't have any motor cut brake levers (I have shimano hydraulic disc breaks). Motor cut brake levers are highly recommended if you only have a cadence sensors or throttle, but with torque sensor you can completely skip it.
 

Ann M.

Well-Known Member
@CHARLES PORRETTO SR, yes you can have a problem with the motor interrupts; generally not a fault of the controller. Try disconnecting the brake interrupts and see if the bike functions. You could have a number of issues, so this is just a shot in the dark. Make certain that the throttle is in zero position; most controllers have a cutout to prevent the power from engaging when a throttle is semi engaged before turning the system on. And it's not unlikely that some other connector may not be plugged in correctly or that the throttle is bad out of the box.
 

Cameron Newland

Well-Known Member
Definitely use brake cutoff sensors. The reason I love them so much is that I sometimes find myself in top gear going 20+MPH and I see a light turning red in front of me. I hold the brake levers down just far enough to cut off motor power (but not far enough to apply the brakes) while I pedal and downshift. If you don't have brake cutoff, your bike might provide motor power and lurch forward while pedaling and downshifting. I like to be in the proper gear when I come to a stop, and brake cutoff sensors make it much easier to do that. If you have an IGH, I guess that this isn't as necessary since you can shift gears while stopped, but for anyone with a rear derailleur, they're especially useful.
 

McCorby

Active Member
Absolutely, especially in mid-motor configuration.
???
Maybe so for Bafang mid drives, but not so for Bosch, Brose, Shimano, and Yamaha mid drives. They all have torque sensors and no throttle. They only provide assist when you are pedaling and there is no lag/run-on when you stop pedaling.
 

fooferdoggie

Well-Known Member
like meI tend to lightly pedal while braking get into the right gear without those cutoffs that could be problematic.
 

McCorby

Active Member
I think they are a necessary safety feature. Unexpected circumstances can arise.
There are no Brose, Bosch, Shimano, or Yamaha powered bikes that use them for motor cutoff. If bikes with these motors have them, they are not wired or they are being used for brake lights.
 

J.R.

Well-Known Member
When this thread was started 4 years ago most people here had never heard of Brose, Yamaha was a motorcycle and Shimano made derailleurs. Seriously though Shimano, Brose and Yamaha were just getting going in North America with their modern mid drives. 4 years ago the vast majority of ebikes had brake cutoffs and Bafang mid drive riders wanted them for hydraulic brakes. It's not a throttle or hub thing, it's a cadence versus torque sensing issue. Cadence sensing requires cutoffs because they don't start or stop instantly. Torque sensing hubs can have them, but it's not an absolute requirement.