# E bike cutt of power brakes



## rokkko (Aug 1, 2017)

Hi,

I got that kind of e-bike with shitty mechanical cutt of power brake system. I want to put shimano mt200 hydraulic system with no cut off power wire. Could I install that kind of brakes into that bike? Could I just disconnect that wire from controller or maybe I will notice an error if I'll do that? Thank you guys!


----------



## BicyclesOnMain (Feb 27, 2021)

You can remove them and it won't throw a code, but stopping immediately after pedaling with be difficult for about 10 feet sometimes. The motor stays on momentarily after you stop moving the cranks, and in that moment it can put you into a wall or off the trail. Also bumping the pedals while moving it around can turn into a rodeo really quick.


----------



## TNC (Jan 21, 2004)

OP, what kind of bike is this on and how is it used? I have a Bafang BBSHD on an SC Bullit used for all kinds of mountain biking. Like you I found the cut-off switches to be a hinderance on the trail. There was an annoying lag before the motor kicked back in. Even as powerful as the pedal assist is on this bike, it has performed a ton better with the cut-off switches removed. I can let off pedaling or keep pedaling under power and just use the brakes to scrub speed for corners, etc. It's a little like fanning the clutch on a dirt motor in corners. It did require me to go to 4-piston brakes and 8" rotors front and rear.

On the shift cable cut-off, I've found it to be very useful. It really does help drivetrain smoothness and wear by killing power momentarily during a shift. The shift cut out and the reengagement of the motor is almost millisecond. The brake cut-offs induced a more noticeable lag before the motor kicking back in.


----------



## Jipman (12 mo ago)

What on earth is a brake cutoff? Why would anyone want brakes to control a motor?


----------



## TNC (Jan 21, 2004)

Jipman said:


> What on earth is a brake cutoff? Why would anyone want brakes to control a motor?


I'm thinking it may have more to do with street or bike path setups...maybe more safety related for those applications. 

And yes, I found it to suck for actual mountain biking. On a Bafang they are just "plug-in" controls that you can disconnect without issue.


----------



## BicyclesOnMain (Feb 27, 2021)

Jipman said:


> What on earth is a brake cutoff? Why would anyone want brakes to control a motor?


All the junk e-bikes use them because the on-off function of the switch in the motor is crude and unpredictable. I test ride ones all the time that will drive you an extra 20 feet after you stop pedaling, so the cut off switches in the brakes are necessary. What's equally annoying is some of them won't start assisting you till you've done a few pedal revolutions. Reminds me of riding a two-stroke motorcycle!


----------



## Jipman (12 mo ago)

I can see the headlines now "Cyclist crashes into a crowd of people, killing 4 of them" Lawsuit: Cyclist did not know that in order to stop your bike you have to stop pedaling it. Bike manufacturer sued for 4 counts of manslaughter for not warning the cyclist to stop pedaling. The jury also found the manufacturer negligent for not putting on a motor cutoff switch which would have reduced the impact speed. Court elevates the verdict to 4 counts of murder. Now manufacturer goes out of business after the settlement and all other bikes are required by a new law to have red stickers that say stop pedaling to stop the bike and we all have motor cutoff switches.


----------



## Jipman (12 mo ago)

BicyclesOnMain said:


> All the junk e-bikes use them because the on-off function of the switch in the motor is crude and unpredictable. I test ride ones all the time that will drive you an extra 20 feet after you stop pedaling, so the cut off switches in the brakes are necessary. What's equally annoying is some of them won't start assisting you till you've done a few pedal revolutions. Reminds me of riding a two-stroke motorcycle!


OK now I get it, they are making up for bad motors. my motorcycle has a cutoff switch on the gear shifter for a quick blip to power shift without the clutch, so I get the shift idea


----------



## BicyclesOnMain (Feb 27, 2021)

Jipman said:


> OK now I get it, they are making up for bad motors. my motorcycle has a cutoff switch on the gear shifter for a quick blip to power shift without the clutch, so I get the shift idea


Yes, exactly. You only find cutoff switches on the worst e-bikes, usually with hub motors. They work with a on/off switch that is supposed to triggered by pressure on the freewheel. Any good mid-drive like Bosch, Shimano, Brose, Yamaha will sense how hard as well as how fast you are pedaling and respond in milliseconds.
Rohloff has an electric shifter that can pair with a Bosch mid-drive to cut power briefly when you shift. Pretty cool stuff. 

Also my next motorcycle will have a quick shifter. I usually shift my motorcycles without the clutch anyways, but it's hard to do when you're riding at a spirited pace on pavement.


----------



## Jipman (12 mo ago)

I'd you get an r1250gsa the gear shift assosy is not very smooth unless under full power oddly enough


----------



## dysfunction (Aug 15, 2009)

Jipman said:


> OK now I get it, they are making up for bad motors. my motorcycle has a cutoff switch on the gear shifter for a quick blip to power shift without the clutch, so I get the shift idea


It's got cheat-mode?


----------



## Jipman (12 mo ago)

dysfunction said:


> It's got cheat-mode?


Yes it has a cheater shifter, some sort of gadget connected to the shifter tells the computer something that helps shift without the clutch. Important on a bike like this that could cost a fortune to fix a busted gearbox on a power shift. Not sure how it works because it's not a motorcycle, its a 700lb computer on 2 wheels with a seat. Also has all the cheater rider aid modes. And cheater wheelie suppression mode too...took me hours to figure out how to do a wheelie cause the computer controls that too. Now they are controlling the engine on lean angle. Radar adaptive cruise. Adaptive headlights. Bmw also has a prototype self driving bike. Soon it will fly


----------



## TNC (Jan 21, 2004)

BicyclesOnMain said:


> Yes, exactly. You only find cutoff switches on the worst e-bikes, usually with hub motors. They work with a on/off switch that is supposed to triggered by pressure on the freewheel. Any good mid-drive like Bosch, Shimano, Brose, Yamaha will sense how hard as well as how fast you are pedaling and respond in milliseconds.
> Rohloff has an electric shifter that can pair with a Bosch mid-drive to cut power briefly when you shift. Pretty cool stuff.
> 
> Also my next motorcycle will have a quick shifter. I usually shift my motorcycles without the clutch anyways, but it's hard to do when you're riding at a spirited pace on pavement.


A Bafang BBSHD...a mid-drive...has cutoff switches for the brakes and cable shift, but they are totally optional. The shift cable sensor is quite valuable, but the brake cutoffs may be useful depending on rider, riding type, riding location, etc. For mountain biking I think the power delivery and riding performance are much better without the brake switches...but they're there is one wants them.

While the BBSHD is cadence sensing vs. torque sensing, it can be programmed quite specifically with a $20 program cable from Luna Cycles and a short trip to Youtube. We have a Trek Rail 7 at our shop that is awesome with the Bosch motor and torque sensing, but I was a bit shocked to see how well a dialed in BBSHD performs on a decent frame for actual mountain biking.


----------



## BicyclesOnMain (Feb 27, 2021)

TNC said:


> A Bafang BBSHD...a mid-drive...has cutoff switches for the brakes and cable shift, but they are totally optional. The shift cable sensor is quite valuable, but the brake cutoffs may be useful depending on rider, riding type, riding location, etc. For mountain biking I think the power delivery and riding performance are much better without the brake switches...but they're there is one wants them.
> 
> While the BBSHD is cadence sensing vs. torque sensing, it can be programmed quite specifically with a $20 program cable from Luna Cycles and a short trip to Youtube. We have a Trek Rail 7 at our shop that is awesome with the Bosch motor and torque sensing, but I was a bit shocked to see how well a dialed in BBSHD performs on a decent frame for actual mountain biking.


Thanks, that's useful information. I haven't seen or tried Bafang's new mid drive motors yet.


----------

