Brake shut off - how important?

K

Kevin

10 mW
Joined
Oct 27, 2009
Messages
26
I'm installing a new front hub kit. Brake shut off levers were included. My problem is that my Shimano shifters are of the Rapid Fire type with integrated brake levers. The handlebar gear shifters are attached to the brake levers.

Would it be absolutely imprudent and dangerous to operate the e-bike without the brake shut off levers?
 
I think it's riskier trusting the usual pot metal brake lever that comes with kits.
Neither of my ebikes have a brake switch and it's not presented any problems
. . . except that the bike is illegal without one.
EDIT: Apparently the biike is legal in this jurisdiction because the throttle has a return spring.
Yay!
 
I think Dog said you're still technically legal zoot, as long as your throttle springs back to zero when you let go.
 
No brake inhibitors on my bike. Just adds to the chaos and all the extra wiring. Cleaner and simpler without. Plus, on a front wheel kit if you hit the front brake and the throttle at the same time (which is hard to do - especially if they're on the same side of the bike) you're unlikely to get thrown off. The brake will stop the wheel (or slow it down) even if you're holding the throttle. On a rear wheel it's probably more possible to get thrown off since you could hit the front brake and the rear wheel would still be turning - throwing your weight forward. Never seen either...

It's another story when we install a kit for a customer. We always add at least the front brake inhibitor just for liability reasons...
 
Seems a little stupid... I mean does your car or motorcycle motor disengage drive when you hit the brake? I wonder what the rationale behind such a requirement is? perhaps it's those strange electric motors and their unpredictable behaviour......


Gow.
 
At first I thought they were silly, but I've had very bad luck with throttles breaking, and many of them were proceeded by an episode of WOT while I applied none, so the break cut-offs have saved my butt. You could probably do without if you have a very easy to reach power switch or disengage button. I still like them personally because I can set the throttle at a cruising speed and not have to mess with it if I just need to slow up briefly.
 
~95% of the people here have never HAD to use their brake cut off switches.

~5%, including me, have definitely used them, are glad they had them, and would not operate without them.

They can be a little problematic to install and get to work correctly. Brake handles also have to match the type of brakes for effective stopping.


Some folks prefer the Full power cutoff switch -- I also have one of these on my home brew ebikes.

I would advise one or the other.

edit: on some controller throttle connections, if you loose throttle ground, the controller throttle input floats full on.
If a stranger is riding the bike, or you have a nice high power motor, you will kiss that brake cut off switch.
Important for newbies.

And yes on my car, touching the brake disconnects the cruise control power.
 
One advantage of using a small motor is I can haul the bike down with the brakes pretty easily with the motor running full tilt. I tried this when I tested a controller which had auto-cruise control on my bike equipped with a 250W 24V motor at 36V just to be sure I could stop in a panic situation. When I let go of the brakes the motor slowly accelerated back up to speed with no drama. I haven't tried it with a powerful motor.

-R
 
The thought of my throttle failing WOT scares me. I'm still recovering from an injury caused by increasing the current limit too much on my bike, turned it into straight line only monster, took off so fast I only just managed to reach a brake lever before falling off the back. If you can stop your bike by putting your feet down then maybe you can do without brake cutoff switches, if you ride a powerful bike then you need them.
 
On the other side, its freaking annoying when you're leaned over trail braking in to a corner, starting to roll on the throttle.. and you get nothing because your finger is still touching the brake lever. Like, unsettling unbalanced offline annoying. Atsed.. I personally like having the cutoff lever, but it took a while to learn what not to do with them.
 
I also thought motor-cut-off brake levers weren't necessary, until I had my wife try riding my revive for the first time...

she twisted the throttle but wasn't going anywhere... then I saw her left hand and she had the left brake lever applied ( ! ) :shock: so I asked her to let go of the throttle immediately ! ! 1

You can accidently burn out the motor without the motor cut-off lever.

Even if you're the only one who rides your bike, an accident like this can happen when you're not alert.

It can also happen if you're riding down hill applying your left brake lever and you forget to release the throttle...

If you don't like the quality of your brake cut-off lever it wouldn't be too hard to rig it up yourself on high quality levers... just use its harness and glue a magnet & sensor on it.

J
 
I use a kill switch mounted on the throttle housing. I have too many wires already. The main reason I don't use brake switches is all the levers I had with switches sucked compared to the ones I'm using.
 
mrzed said:
(2) The motor of a motor assisted cycle must turn off or disengage if

(a) the operator stops pedaling,

(b) an accelerator controller is released, or

(c) a brake is applied.

http://www.bclaws.ca/Recon/document...C 1996 c. 318/05_Regulations/25_151_2002.xml

So you're fine there. Those listed are options, not all requirements. One of the the three is sufficient.
Click to expand...
Thanks for clarifying that.
Now as long as I don't hit the thumb throttle thinking it's the bell, I should be okay.
Maybe I've just been lucky all this time. When I first got the bike I was sort of nervous without the brake switch.
A kill switch to disconnect the battery makes more sense to me for an added safety measure.
 
Ironically, the controller I was sent doesn't have a connector for the brake shut off. The seller offered to send me a different controller, but for now I've declined to change out.

I will be mounting the controller on the front and top of the rack, and the controller's on/off switch will be easily accessible as I ride.

I guess this would serve as a "kill" switch if needed, wouldn't it?
 
Yep, a switch is nice and simple and works although I would make sure it's weather resistant at the least... it tends to rain everywhere once in a while :)

I'm part of the 5% who couldn't go without them, however, this is mainly b/c pulling them activates regen which is a huge asset if you don't have disk brakes. Every little bit of stopping power in an emergency helps :)
 
Hey guys !

I spotted this stuff about brake cutout switch importance... if you think you may turn the throttle while applying brake to the hub motor by accident then yep pretty important. Also equally, if you want regen to function efficient and intuitively... brake cutout is really the only way.

So the controller you received doesn't have the wires already? All that should be needed is to run a single thin wire along with the existing loom which goes for the throttle. Open the controller and post pics of the PCB to be sure, but most likely there will be a pad marked "EBS -" (near where the wires come out), solder this new wire to this pad.

The new wire running to "EBS -" (which for consistency with other infineon wiring colors I'm going to refer to as Yellow from now on) is connected (shorted) to one of the existing ground wires already present in the loom (just use the black wire going to the throttle... tap into it) to activate. So... run 2 wires to whatever switch you decide to use (must be normally open type switch) and whalla... you have a functional eBrake cutout (or regen).

With regards to the switch... I have many solutions for you as I have I employd one or the other of these on most of my builds - I am (literally) working on the thread for them and will update this post when it's finished with pictures in a little while (my goal for tonight, while waiting for a megapack to charge - 10S12P ) but there are methods as simple as visiting your local radioshack and getting a reed switch (the tiny kind) with N.C. contacts and mounting them beneath your brake pull housings attached with anything (glue, jbweld?, epoxy, ca) and then just attach a magnet to the moving part of your pull arm so when you pull them the magnet is moved away from the switch and it will go closed and short the Yellow wire to ground (5v ground). You could reverse this using a N.O. relay mounted towards the endpoint of the pulls travel, then place a magnet on the back of the pull so when you use the break the N.O. relay is closed by the magnet and eBrake is activated.

Another (better) method (for water safety, simplicity and size) is the hall effect sensor method. I will detail this out in my other thread but you can get hall sensors dirt cheap or salvage them from any bldc motor which may have them (some CD drives, misc parts) or you can just order them for a few bucks each (3-6). I have some so tiny (SMT type) which I use within my hobby/rc motors to enable use with infineon controllers. In either case, these work the same as the magnet (sort of) but usually the send positive voltage so... solder the ebrake line (the yellow wire) into th EBS + instead of the EBS -.

Another (sorry) point to make, using this method means you don't have to put the switch on the pulls.... controller in the back of the bike? Mount a hall sensor on your brake mounts some where and a small neodium magnet on the brake arms or caliper moving part... now you get the cutout but the point of interface can be the front or rear wheel... if you have a partiall exposed brake line... you can use th cable along the length too...

I'm just trying to help you think out of the box for eBrake locations and such...

I never use the stock eBrake pulls... if you need 2 send me a PM.

-Mike
 
I don't use brake switches either. I have to manually reset my throttle back to zero since the spring isn't all that great. I got a red button on my controller to kill everything if I need to though.
 
Icewrench said:
Another angle on brake switch location.
From Patriots build , not sure what to call that switch.

Click to expand...
Yep, that's a quick and clean looking solution.
Whether it's any good depends on its weather resistance.
Patriot called it "a simple compression switch".

The switch came off some kids bike horn/light combination @ Deal Extreme
The least expensive, light only, ~$4 option is perpetually sold out.
Otherwise you've got to spend ~$7 to $9 to get the switch and throw the rest of the lights and crap in the junk box.

I can't imagine the raw switches costing more than dollar each in lots of a hundred.
You'd probably have to buy a thousand or more before anybody would talk to you.
I'll ask at one of the two local electronics shops if they might know a source and be able to order a bunch direct from China.
Before committing to a gross or more, feedback from people who've used this switch would be appreciated.
 
Some kind of "emergency off " is a dang good thing. I just set up battery connectors where I can reach em easy, and just jank out the wires if need be. Another option could be to put a toggle switch somewere easy to reach connected to the brake lever circuits. Then you have a handlebar off switch, and keep the bikes nice brake levers.
 
You can wire a kill switch in parallel to your brake shut off too, because if your throttle gets stuck on full a simple switch makes good for shut off as you can operate this switch on and off to get home and have the bike under control without having the brakes always engaged always require hands on. Its not always good to hard switch your controller off while the bike is in motion.
 
Ohh and I forgot. Using brake at least one brake switch (Left brake) its makes it better on your batteries and dropouts, or front forks, if your motor is a front hub, as often it is possible to accelerate and brake at the same time, not a good combination to have happening on a long ride.
 
Icewrench said:
Another angle on brake switch location.
From Patriots build , not sure what to call that switch.

Click to expand...


Yeah, I asked an electrician at work, he said is looks like a basic internal spring compression switch. And yes, I bought the cheapy light for about $3-4 from DX at the time, just to get the switch. The cheap light still works without the switch, so I put it on my daughters bike.

As far as weather goes. I did ride home once or twice in some rain, and a few times on wet roads. The fact that it's under you bum on the rear, and the bike has full fenders offers alot of protection to begin with. However, after riding, the little rubber accordian shroud had some dirt on it. Of course this accumulated over several rides. The switch itself has never failed. It's so simple, it would probably have to get filled with dirt or water somehow to actually short out.I personally would recommend it over most other apps where actual brake/switch levers are not able to be used.
 
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