Brake lever cut off questions

[Fordulike]

As my planned electric bike build is verging on slightly the wrong side of the law anyway, does an electric bike require the cut off lever switches by law?
Also has anyone ridden a bike without them. Does it make them dangerous?
Probably wont be fitting a pedelec, so i can cut the power with the throttle at any time.
A lot of the new non electric bikes appear to have integrated shifters and brake levers, which makes choice of bike suitable for a build more difficult.

 

[Grizzly Bear]

I've stopped using them, I think they are dangerous. A motorcycle style kill switch is useful on a powerful ebike, but if you're running something like a little Bafang, then the brakes can easily overcome the motor power, that's assuming you have proper brakes that work that is!

Griz

 

[jerrysimon]

I initially ran my Brompton Tongxin conversion without cutout brakes. I then fitted one and now in fact have fitted both cutout brakes.

The thought of the front wheel spinning without being able to cut it is scary. Although mine is throttle only and letting go of the throttle would normally stop it you just don't know, it may get jammed or you may panic and push the throttle by accident.

Grabbing the brakes is a natural reaction in an emergency situtation and knowing that both mine cut all power is re-assuring.

I would have thought that was even more important on a higher powered electric bike.

I also have a cut out switch that I can hit which kills all power, again if something jams or shorts.

Regards

Jerry

 

[John L]

Hi Dave

I think you read earlier that I "adapted" the integrated gear shifter and brake lever (with a hacksaw blade ) so I could fit the cutout brake. I definitely feel more secure knowing that the motor will stop automatically if I have to jam on.

I have only one issue with the cutout brake that comes with the sunlova kit - you can't adjust the brake lever (no adjustment screw). My brake lever is traveling a long way before the brakes grab the wheel rim.

John

 

[Fordulike]

Thanks for the replies.
John L, you were certainly brave doing a mod on your integrated system
What about the legality of a bike with no cut offs?
Also, do the Wuxing levers open the circuit when pulled or close it?

 

[flecc]

Thanks for the replies.
John L, you were certainly brave doing a mod on your integrated system
What about the legality of a bike with no cut offs?
Also, do the Wuxing levers open the circuit when pulled or close it?

Pedelec bikes usually don't have cutoffs and are entirely legal, stopping pedalling cuts the power of course. Brake cutofs are usually fitted to bikes that allow throttle only power, but I agree with Griz, not essential. I'm not aware of the law requiring them.

When the law changes shortly and only pedelec is possible, all brake cutoffs on new bikes will disappear permanently.
.

 

[Fordulike]

So i can just omit the cut off levers without any mods to the controller?

 

[flecc]

Usually yes, many make contact to perform the cutoff, so leaving the connections in the controller open circuit leaves it working. On the minority that work the other way, shorting the pairs together does the trick.

Try it open circuit first, that works on both my bikes. If it doesn't work on yours, just put a link wire across each pair of cutoff connections.
.

 

[Pedalo]

Has anyone experimented with reed switches and magnets? I was thinking of trying this with my Brompton build but won't bother if they don't work well for this purpose.

 

[Fordulike]

In theory yes.
I remember years ago i built a record player turntable using a reed switch/magnetic drive. It was only an experiment and produced excruciating amounts of audible wow and flutter
Reed switches are capable of handling fairly high voltages, but not sure they can handle large currents.
What context would you be using the set up in, the braking system?

 

[Old Timer]

If you are in traffic or around people it makes sense to use throttle so that you have control of speed and drop off and then brake cut off is not quite so important. When using pedelec(as will be the case when the new law comes in) then from my riding experience brake cut off is important, if your system is set up correctly with the supplied magnet pedelec disk you`ll find that a short turn of the crank fires up the motor and drop off of the motor is by no means instant when you stop pedalling. Because I had integral gear change with brake levers on one bike I converted I just didn`t bother with the cut out brake levers because to be honest I live very rural with next to no traffic.
Then shortly after completing the conversion I rode the bike up the lane to the next junction, checked my mirrors and did a U turn and as I was crossing the joining point of the lanes where all the gravel and shite gets washed and pushed to I gave a half turn on the crank (whilst lightly holding the non microswitch levers) and of course the bike front wheel skidded in the gravel and sand just at the unbalanced moment and the bike slid sideways. Luckily it was slow enough for me to jump off the saddle and stop. If I had had microswitched levers the light grip I had on them would have given me the feathering of the brakes you require when turning slowy plus the prevention of the motor from firing up.

Of course micro switched brake levers are important when riding with pedelec. Inconvenient YES when you have combined gear change levers but stupidity not to fit them in my book.

 

[Fordulike]

Of course micro switched brake levers are important when riding with pedelec. Inconvenient YES when you have combined gear change levers but stupidity not to fit them in my book.

I ride mostly on bike paths when i can, so i'll probably do without the brake levers and pedelec on my project.
As for the situation you describe, i get that with my current Cyclamatic.
I've learnt to stop pedalling moments before any slow sharp turns and either let it coast round or use the throttle sparingly.
I'm hoping to integrate a system where the throttle steps up the motor nice and proportionally to the throttle input for complete control.

 

[flecc]

Of course micro switched brake levers are important when riding with pedelec. Inconvenient YES when you have combined gear change levers but stupidity not to fit them in my book.

Well that means that the most experienced e-bike markets in Europe where they sell many times the number we do have it wrong, since EU pedelec bikes don't have brake cutoffs. Look at the 20 odd makes using the Panasonic unit for example, no cutoffs to be seen anywhere. Same goes for all the other European produced makes using other motors that we see over here.
.

 

[flecc]

As for the situation you describe, i get that with my current Cyclamatic.
I've learnt to stop pedalling moments before any slow sharp turns and either let it coast round or use the throttle sparingly.
I'm hoping to integrate a system where the throttle steps up the motor nice and proportionally to the throttle input for complete control.

The problem is the poor design of all cheap Chinese pedelec bikes, and you are absolutely spot on with your approach. Pedelec bikes need decent torque sensing so that rider touch is reflected in motor output as happens on the Panasonic, Yamaha, Sunstar and Giant Freedom, all higher priced units, and other makes of e-bikes produced in the EU.

Properly designed pedelecs never need brake cutoffs.
.

 

[Fordulike]

I think it's all about motor controllability.
If you have a bike system, like Old Timer described, that has a little bit too much kick when the pedelec operates at slow speed, then yes you need to be able to tame this with brake cut offs.
If the pedelec and controller is well designed, then it shouldn't give the wheel too much power in situations as a slow turn.
I should imagine a lot of the kits are designed to get you going at higher speed and pay no attention to very low speed maneuvers.
As for any worries of the throttle sticking on and the bike zipping off with no hope of controlling it, i'll just reach down and switch the power key to off.

 

[Fordulike]

The problem is the poor design of all cheap Chinese pedelec bikes, and you are absolutely spot on with your approach. Pedelec bikes need decent torque sensing so that rider touch is reflected in motor output as happens on the Panasonic, Yamaha, Sunstar and Giant Freedom, all higher priced units, and other makes of e-bikes produced in the EU.

Properly designed pedelecs never need brake cutoffs.
.

Beat me to it

 

[Grizzly Bear]

Has anyone experimented with reed switches and magnets? I was thinking of trying this with my Brompton build but won't bother if they don't work well for this purpose.

I have, and they do work, I just don't like brake cutouts. I bought some reed switches that are use for model railways, I wired them into the thottle circuit, you are then able to keep the better quality brake/gear shifters, instead of the rubbish cutout lever assemblies.

 

[Old Timer]

Well that means that the most experienced e-bike markets in Europe where they sell many times the number we do have it wrong, since EU pedelec bikes don't have brake cutoffs. Look at the 20 odd makes using the Panasonic unit for example, no cutoffs to be seen anywhere. Same goes for all the other European produced makes using other motors that we see over here.
.

I get your point Tony but that also means that all the bikes and kits that have/are using microswitch levers have it wrong?
All my bikes have them inc the Alien kits and the Alien Aurora ready built bike and Annes bikes inc the Synergie Breeze.
I see the problem converting a bike with integral brake gear levers(although I got over it nicely) but can`t see why including them in ready made off the shelf E bikes would be a problem.
I know the new and old Oxygen bikes have them, not sure about Wisper?

It`s horses for courses I suppose but can`t see why anyone would want to be cornering whilst pedalling as you do at times with the motor still pushing and perhaps more so with a front hub.
When I jump on my bike and pull down to the end of my drive, check to see the road is clear with a brake on I know that the bike isn`t going to shoot forward if I slightly loose balance( which we all do now and then) and I inadvertantly twist the throttle.

 

[flecc]

I get your point Tony but that also means that all the bikes and kits that have/are using microswitch levers have it wrong?

It's the Chinese made pedelecs that tend to get it wrong, not having torque sensing or it being poorly implemented, and it's particularly difficult to get right with fairly powerful wheel hub motors.

It can be done though, as Giant have now done on the Freedom model. Hopefully other manufacturers will take that cue and improve their models, but I doubt if the makers of the budget end will be bothered to try since it adds cost.

There have been some improvements over the years though. The first version of the Currie kit* and the early first version of the eZee pedelec systems were truly lethal, high powers kicking in at full force the moment a pedal was touched or a throttle opened. I've got a repaired panel door that had a hole punched through it by one of these!

*900 watts!
.

 

[Old Timer]

It's the Chinese made pedelecs that tend to get it wrong, not having torque sensing or it being poorly implemented, and it's particularly difficult to get right with fairly powerful wheel hub motors.

It can be done though, as Giant have now done on the Freedom model. Hopefully other manufacturers will take that cue and improve their models, but I doubt if the makers of the budget end will be bothered to try since it adds cost.

There have been some improvements over the years though. The first version of the Currie kit* and the early first version of the eZee pedelec systems were truly lethal, high powers kicking in at full force the moment a pedal was touched or a throttle opened. I've got a repaired panel door that had a hole punched through it by one of these!

*900 watts!
.

Well, I agree that a more sophisticated pedelec control would be welcome, can you imagine what the Aurora is like at full power? even at low power it spins away.
I still don`t really get why throttles are being phased out. Was there a reason given for the change? As I see it the change will have an effect on anyone with a disability or from getting over an illness like I did recently.