Hydraulic cut-off brakes

I never have understood why Ebikes think they need a mechanism of cutting power when the brake is applied.....?
Pedal bikes dont have that,..
Mopeds dont have it...
Motor scooters dont have it...
Motor bikes dont have it....
Cars dont have it.. ?
Why is this considered necessary for electric bikes ??
 
If you've ever had an e-bike fail to WOT then you'll be thankful you have an e-brake...
 
Even my (very illegally over powered ) Ebike motor driving through the chain, is no match for the basic rim brakes fitted.
If i chose to hit the brakes at WOT even in low gear, it would simply pop a fuse ( been there, done that)
So why a normal, legal 250W -750W drive, fitted with supa hydro discs, should need a brake cut off....is still a mystery to me ! :roll:
 
Hillhater said:
If i chose to hit the brakes at WOT even in low gear, it would simply pop a fuse ( been there, done that)
So why a normal, legal 250W -750W drive, fitted with supa hydro discs, should need a brake cut off....is still a mystery to me ! :roll:
Click to expand...
E-brakes save from popping a fuse and walking home, genius :roll:
 
Hillhater said:
I never have understood why Ebikes think they need a mechanism of cutting power when the brake is applied.....?
Pedal bikes dont have that,..
Mopeds dont have it...
Motor scooters dont have it...
Motor bikes dont have it....
Cars dont have it.. ?
Why is this considered necessary for electric bikes ??
Click to expand...
You need them if you use the PAS because the power doesn't cut immediately after you stop pedalling. Also, most Ebike throttles are thin plastic, which breaks easily. When they break, you normally get half-throttle because you need the low-throttle magnet hard up against the hall sensor to get zero throttle. I've broken two throttles like that.
 
full-throttle said:
E-brakes save from popping a fuse and walking home, genius :roll:
Click to expand...

I thought that was what pedals were for ?..(should it ever happen):wink:
...but actually i would just fit the spare fuse that i carry. :mrgreen:

What do you do if one of the brake cut out switches or connections fails and kills your motor ?
More switches and wiring means more potential for problems.
 
Hillhater said:
full-throttle said:
E-brakes save from popping a fuse and walking home, genius :roll:
Click to expand...

I thought that was what pedals were for ?..(should it ever happen):wink:
...but actually i would just fit the spare fuse that i carry. :mrgreen:

What do you do if one of the brake cut out switches or connections fails and kills your motor ?
More switches and wiring means more potential for problems.
Click to expand...

The circuit for a e-brake is normally open. So if you have a fault, just unplug and go.

In my book, the ebrake handles are good for a couple situations. With PAS and/or cruise control, it's a need or else you'll have to blip the throttle every time you wish to stop. Then, the last useful (albeit rare) situation is run away throttle or standing around meddlesome kids. There's no clutch or 'neutral' with our bikes, so a careless throttle grab on a powerful setup could lead to comedy or pain (depending on where you were standing at the time)
 
cal3thousand said:
The circuit for a e-brake is normally open. So if you have a fault, just unplug and go.
Click to expand...
..but not in all cases.
..and what if the fault is on the controller side of the plug ?

cal3thousand said:
In my book, the ebrake handles are good for a couple situations. With PAS and/or cruise control, it's a need or else you'll have to blip the throttle every time you wish to stop.
Click to expand...
With PAS ? ...shouldn't that stop ASSISTING when you stop pedaling ?
Cruise control ?? do you really get the chance to use cruise control ?... if you can switch it on...you could switch it off too !

cal3thousand said:
Then, the last useful (albeit rare) situation is run away throttle or standing around meddlesome kids. There's no clutch or 'neutral' with our bikes, so a careless throttle grab on a powerful setup could lead to comedy or pain (depending on where you were standing at the time)
Click to expand...
..So you stand with your hand on the brake ? ....so do I,... ( or i turn the safety switch to "off" if i think someone is likely to fool around)

Really , these are poor justifications for the extra complexity of brake cut off switching systems.
The only genuine reasons i can think of is for activating regen... if you happen to have that facility ( DD hub and suitable controller etc )....or simply to comply with the laws in your locality.
 
Hillhater said:
cal3thousand said:
The circuit for a e-brake is normally open. So if you have a fault, just unplug and go.
Click to expand...
..but not in all cases.
..and what if the fault is on the controller side of the plug ?

cal3thousand said:
In my book, the ebrake handles are good for a couple situations. With PAS and/or cruise control, it's a need or else you'll have to blip the throttle every time you wish to stop.
Click to expand...
With PAS ? ...shouldn't that stop ASSISTING when you stop pedaling ?
Cruise control ?? do you really get the chance to use cruise control ?... if you can switch it on...you could switch it off too !

cal3thousand said:
Then, the last useful (albeit rare) situation is run away throttle or standing around meddlesome kids. There's no clutch or 'neutral' with our bikes, so a careless throttle grab on a powerful setup could lead to comedy or pain (depending on where you were standing at the time)
Click to expand...
..So you stand with your hand on the brake ? ....so do I,... ( or i turn the safety switch to "off" if i think someone is likely to fool around)

Really , these are poor justifications for the extra complexity of brake cut off switching systems.
The only genuine reasons i can think of is for activating regen... if you happen to have that facility ( DD hub and suitable controller etc )....or simply to comply with the laws in your locality.
Click to expand...


How can it fail on the controller side of the plug? If it could do that, it wouldn't matter if you had the switches connected or not.

Yes, controllers should stop power when you stop pedalling, but they don't, so you need brake cut-offs.

If you fit a cruise control, they're essential, but not only that, they're really useful for controlling the power. I leave my cruise on, and use the brakes to cut power when I want to slow down or stop, and then let go the brakes to accelerate back up to cruise speed. No need to touch the throttle, which makes very comfortable riding.

You're impression of brake switches, to me, seems somewhat unrealistic. They're very reliable, and even if they did give problems, you only have to disconnect them or cut the wire. I have them on all my bikes. I can't say I wouldn't ride a bike without them, but, for me, the advantages far out-weigh the minimal disadvantages. They make the bike both more pleasant and safer to ride. I can understand your point of view to an extent if you have a throttle-only electric motocross bike, but it's a different situation to use a bike on the road for normal commuting.
 
Chalo said:
Magnetic micro proximity switches usually cost more than contact microswitches, but they offer different mounting options. Some of them are really small.

Standex-R12575-micro-proximity-switch.jpg
Click to expand...

Where can I buy this one?
Looks fine for my project :mrgreen:
 
my crystallite controller has a soft power switch together with an ebrake ? switch which I have mounted on the handlebars on the left of my throttle/cruise.

I assume switching this off is just as good as a brake cutoff in case of throttle runaway ?

you can see it mounted here in the video (P.S. try not to laugh too hard, it was my first ride on this beast)

[youtube]IsodEjnNFV8[/youtube]
 
Instead of hacking a switch on my hydraulic brakes, I had an old mechanical brake lever with a switch in it, and just hooked that up separately so I activate it when I grab the hydraulic lever. This gives the option of just using the E-brake separately. I can game this and get a lot more regen on a ride if I am getting Range Anxiety.
 
Hillhater said:
I never have understood why Ebikes think they need a mechanism of cutting power when the brake is applied.....?
Pedal bikes dont have that,..
Mopeds dont have it...
Motor scooters dont have it...
Motor bikes dont have it....
Cars dont have it.. ?
Why is this considered necessary for electric bikes ??
Click to expand...
Another reason: On our UK forum, a guy was running a 500w BPM without cut-off switches. His throttle stayed on for whatever reason, so he had no choice but to overwhelm the motor with the brakes, which caused so much current to flow that it melted the solder off the reinforced traces in his controller. He was lucky that he didn't burn his motor too:
http://www.pedelecs.co.uk/forum/electric-bicycles/15845-fault-finding-help.html
 
d8veh said:
...so he had no choice but to overwhelm the motor with the brakes, which caused so much current to flow that it melted the solder off the reinforced traces in his controller.
Click to expand...

So his "modified" controller doesnt have current limiting or over current protection ! ( or even a simple fuse ) :roll:
..and he has no other means of cutting power ? ( control switch etc) such that once the battery is connected, everything is "live" ?
 
Hillhater said:
d8veh said:
...so he had no choice but to overwhelm the motor with the brakes, which caused so much current to flow that it melted the solder off the reinforced traces in his controller.
Click to expand...

So his "modified" controller doesnt have current limiting or over current protection ! ( or even a simple fuse ) :roll:
..and he has no other means of cutting power ? ( control switch etc) such that once the battery is connected, everything is "live" ?
Click to expand...
Try stalling your motor with the brakes for about 10 seconds to see if you're protected. The one time I stalled a motor for a split second, it damaged the gears.

No he didn't have an accessible master switch and even if he did, imagine what you'd do when the throttles stuck on full when you' re turning a corner completely taken by surprise, would you go for the brakes or the switch, bearing in mind that you're already going too fast for what you want?
 
Dlogic said:
Yes, that´s the same switch i´ve ordered. Just like Chalos. :) Mine has a metric M10 * 1 thread though.

.
Click to expand...


Hi Diologic,

I think I'll attempt to do something similar to your idea Where did you find the pressure switch with metric fittings?

Best
 
Dlogic said:
I found my switch here:

The M10 * 1 was modified to M8 * 0,75 in order to make things more compact. :)
Click to expand...

Wow cool. Thanks - so how do you make it smaller :? - would love to know how. :)
 
That´s no big deal since the rear part of the switch is hexagonal. Just clamp that part in the lathe and work it down to a diameter of 8mm. Next cut the new thread on it and you´re all set. :)

2cx7y2f.jpg


Located on the left side is the original t shaped brass connector. The powder coated and rethreaded one for the avid code r brakes sits on the right side. On the center the hydraulic pressure switch has been installed. This thing goes between the brake lever and caliper. Once the lever is pulled the oil pressure actuates the switch. A clean and moisture proof solution.

The only downside is that you´ll need to bleed the brakes. Without the 50€ avid bleed kit an impossible task.
 
Dlogic said:
A clean and moisture proof solution. .
Click to expand...


Yes, very clean indeed. Actually the most awesome hydraulic cut off switch for DOT 5.1 I've seen on ES until now or anywhere else :D Dlogic, you rule. :wink:

Just to make sure, your Bill of Materials would be:

1x T-connector with M8 fittings
3x Male to Female adapter (Also (M8x0,75)?)
2x Avid tube fittings (what is the size of the avid thread, also (M8x0,75)?)

Again, excellent work!
 
Thanks for the charming words. :)

Finally some spare time was found to fit the switch to the bike. The intention was to use it for activating the rear brake light. But since it´s so sensitive it could also be used to activate regen. With just a very light squeeze on the lever it closes long before the brake pads begin to excerpt pressure to the disc.

Still have to wire it up and tuck those cables neatly. Maybe this weekend it´ll be all set. :mrgreen:

30l2zkg.jpg


1. The tube fittings from Avid cost around 6€ a piece. Two are needed.
2. A few years ago a taps and dies set was bought that has all metric threads starting from M2 all the way up to M16. Don´t ask me the price though, you´ll think i´m nuts!
3. The bleed kit from Avid costs another 50€.
4. The T connector comes with M10*1 threads and was reworked using a lathe. The M10 threads look way to bulky.

The Avid tube fittings have an M8*0,75 mm thread. You can also make these yourself on a lathe and save those 12€.
Precise cutting tools are a must here or else you´ll end up with a leaking system. :twisted:
 
Dlogic said:
The bleed kit from Avid costs another 50€.
Click to expand...
You can make your own for much less. Apart from the 2 fittings all the parts are easily available. The fittings are same thread as some pneumatic ones. Got a whole bag of them :D
 
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