Thanks very much for this, as this seems an ideal solution. The illustration in your older post is good, as even with my limited electrical knowledge I can understand and replicate it.

Sadly, walk in shops such as Maplins and Tandy’s disappeared off the high street some years ago, as they were always good for purchasing electrical components.

Just to make sure I have understood the introduction of a 10k potentiometer is this the connection method?

I have used identical Juliet connectors to save spicing into the existing throttle wires.

Just to make sure I have understood the introduction of a 10k potentiometer is this the connection method?

I have used identical Juliet connectors to save spicing into the existing throttle wires.[ATTACH=full]62767[/ATTACH]

Yes, that's correct. Please let us know how you get on. When set correctly, it should have the effect that the throttle will do nothing until nearly fully twisted. Just the last bit will give the 6km/hr. In other words, it has the effect of cutting off the bottom part of the throttle operation.

Hi Saneagle,

Will do,

thanks.

Hi Saneagle,

I’ve noticed on the Juliet plugs and sockets I have sourced that the three cables are black, red and blue. Not wishing to assume where these go I was thinking of inserting the plug into the controller socket and checking the black and red are respectively live and ground and confirming the polarity, meaning the blue would be the signal wire.

What do you recon, or could this be done at the throttle wire to avoid accessing a live supply, and if so how.

Your knowledge on this would appreciated.

Hi Saneagle,

I’ve noticed on the Juliet plugs and sockets I have sourced that the three cables are black, red and blue. Not wishing to assume where these go I was thinking of inserting the plug into the controller socket and checking the black and red are respectively live and ground and confirming the polarity, meaning the blue would be the signal wire.

What do you recon, or could this be done at the throttle wire to avoid accessing a live supply, and if so how.

Your knowledge on this would appreciated.

There's only one wire that's live, and it's only 5v. It won't do any harm if you short it. The only reason you need to get the correct sequence is for it to function correctly. If you have a matching connector with flying leads, plug it in to the switched on controller and measure which is 5v, then check which of the other two is ground by checking resistance/continuity.

Hi Saneagle,

I wired the 10k pot using the juliet plugs, plugged it in the between the existing throttle plug an controller socket and the throttle operation was not operative and the potentiometer allowed some various speeds randomly with the speed on the display showing 3mph when it appeared to be maximum speed of 15mph.

not the result I was after.

I have resorted to a physical throttle stop set to 6mph on the flat but soon as I hit an incline it slows to about 4mph so not an ideal solution.

 

 

 

 

stop

Hi Saneagle,

I wired the 10k pot using the juliet plugs, plugged it in the between the existing throttle plug an controller socket and the throttle operation was not operative and the potentiometer allowed some various speeds randomly with the speed on the display showing 3mph when it appeared to be maximum speed of 15mph.

not the result I was after.

I have resorted to a physical throttle stop set to 6mph on the flat but soon as I hit an incline it slows to about 4mph so not an ideal solution.

 

I don't think you can use an analog throttle to control something like cutoff speed. The throttle voltage is translated to a current going through the motor, you should still hear the motor going when you reach the maximum setting regardless of the incline. That will defeat the objective of cutting off the motor when you reach a preset limit like 4mph.

The practical solution for OEMs is to ask the manufacturer of the controller for the firmware to be reprogrammed. If you have to make do without the assistance of the manufacturer, you will need to have a separate speedometer and program it to activate the brake sensor when the bike reaches the desired speed.

Hi Saneagle,

I wired the 10k pot using the juliet plugs, plugged it in the between the existing throttle plug an controller socket and the throttle operation was not operative and the potentiometer allowed some various speeds randomly with the speed on the display showing 3mph when it appeared to be maximum speed of 15mph.

not the result I was after.

I have resorted to a physical throttle stop set to 6mph on the flat but soon as I hit an incline it slows to about 4mph so not an ideal solution.

 

 

 

 

stop

There's no reason that it shouldn't work. A potentiometer is a voltage divider. All it does is reduce the voltage on the throttle signal line. With the adjuster fully one way, there is no resistance, so the full throttle signal can get through. If it doesn't work like that, theremust be a mistake in your wiring.

I don't think you can use an analog throttle to control something like cutoff speed. The throttle voltage is translated to a current going through the motor, you should still hear the motor going when you reach the maximum setting regardless of the incline. That will defeat the objective of cutting off the motor when you reach a preset limit like 4mph.

The practical solution for OEMs is to ask the manufacturer of the controller for the firmware to be reprogrammed. If you have to make do without the assistance of the manufacturer, you will need to have a separate speedometer and program it to activate the brake sensor when the bike reaches the desired speed.

You can because the throttle is a speed controller. You can try it. Open the throttle a bit and you get a low speed, a bit more goes faster and so on. It works by giving a voltage in the range 1.2v to 3.8v.

 

The range 0v to 5v is divided up by the ADC into say 256 steps. In that case it needs a value of 62 before it does anything and 195 to give maximum speed of say 20 mph, which would mean a value of 87 for 6km/hr. 87 would conver back to 1.7v

 

If you put the signal through a potentiometer divider, you'd need to divide the max signal of 3.8v by around 45% so the potentiometer would need to be set just past half-way.

 

The controller doesn't know what you're doing with the throttle. It only sees the voltage coming to it on the signal wire and responds accordingly. Around 1.7v should give the 6km/hr. The signal needs to be very clean. You can't use PWM.

Hi whoosh and Saneagle,

Having read some posts on other sites I thought I’d give some other configurations a try.

Connecting just 2 of the pot terminals in between either the live wire or the signal wire threw up an error code, but when connecting 2 of the pot connections in between the ground wire allows restriction of the maximum speed when operating the throttle, no error codes and thenmph seems to be displaying correctly.

How this works i’m not sure, but will solder the configuration and set the pot to 6mph which is 2mph over the permitted limit but I can’t see me getting my bike confiscated for a 2mph discrepancy.

I’ll install a secluded bypass switch so that should my muscle cramps or asthma develop mid ride I can get home on the option of full throttle.

Hi whoosh and Saneagle,

Having read some posts on other sites I thought I’d give some other configurations a try.

Connecting just 2 of the pot terminals in between either the live wire or the signal wire threw up an error code, but when connecting 2 of the pot connections in between the ground wire allows restriction of the maximum speed when operating the throttle, no error codes and thenmph seems to be displaying correctly.

How this works i’m not sure, but will solder the configuration and set the pot to 6mph which is 2mph over the permitted limit but I can’t see me getting my bike confiscated for a 2mph discrepancy.

I’ll install a secluded bypass switch so that should my muscle cramps or asthma develop mid ride I can get home on the option of full throttle.

Well, done. I was pretty sure it would work. Thanks for the update. This gives a way to legalise all the Amazon bikes with independent throttles for £0.12 and twenty minutes work.

For on the spot check purposes i have set the throttle to 5mph which in reality is useless as a means of ones, well me anyway, initial take off mode as it takes me a while to get my balance and both feet on the pedals.

Whoever came up with the 4mph rule has no idea of the needs of the elderly and those not so fit wishing to to back in cycling, bear in mind that e-bikes are supposed to be an aid to get those very people back into cycling.

Edited April 20, 20251 yr by Bobbo1260

For on the spot check purposes i have set the throttle to 5mph which in reality is useless as a means of ones, well me anyway, initial take off mode as it takes me a while to get my balance an both feet on the pedals.

Whoever came up with the 4mph rule has no idea of the needs of the elderly and those not so fit wishing to to back in cycling, bear in mind that e-bikes are supposed to be an aid to get those very people back into cycling.

The 4mph thing is designed to be an aid when you have to push the bike, that's why it is called walk assist. It usually only has a low power output and is not meant to allow you to start without pedalling.

On my Engwe the walk assist is applied by holding the minus button. The 4ph via the throttle is to aid initial take off.

On my Yosepower kit holding the minus button also delivers 4mph but the throttle allows 15mph which puts it in breach of the EPAC requirements, hence me setting the achievable speed to 5mph when using the throttle.

The 4mph thing is designed to be an aid when you have to push the bike, that's why it is called walk assist. It usually only has a low power output and is not meant to allow you to start without pedalling.

That's actually not correct. Who said it's called walk assist? It was included in EN15194, where it's called "startup assisistance mode", so that people, who had difficulty starting up, could get a bit of assistance. Obviously, it can also be used as a walk assist button, so the clever person who thought of that rule mentioned both. What you guys are saying is a blinkered view based on nothing but your own paradigms.

Here it is from Google AI:

"The 6 km/h (3.7 mph) speed limit for electric bikes without pedaling, allowed by EN 15194, is designed to assist riders who have difficulty starting or who might benefit from a small amount of power assistance at low speeds, such as when dealing with a disability or injury. This "twist and go" feature is intended for start-up assistance only and must cut off if the rider is rolling faster than 6 km/h without pedaling".

 

From EN 15194:

"4.2.12 Start-up assistance mode

4.2.12.1 Requirements

An EPAC can be equipped with a start-up assistance mode that operates up to a maximum speed of 6 km/h. This mode shall be activated by the voluntary and maintained action of the user either when riding without pedalling or when the user is pushing the cycle. "

Sorry, but it is correct.

In the instructions for my Yosepower conversion kit and my Engwe LS20e both have a walk assist mode for when pushing the bike which states this is not to be operated when riding, as it is low power output.

The throttle on the Yosepower kit operates up to 15.5 mph where as the LS20e throttle operates up to the legal 3.7mph.

 

Yosepower instructions below:

 

Engwe instructions further below::

 

Sorry, but it is correct.

In the instructions for my Yosepower conversion kit and my Engwe LS20e both have a walk assist mode for when pushing the bike which states this is not to be operated when riding, as it is low power output.

The throttle on the Yosepower kit operates up to 15.5 mph where as the LS20e throttle operates up to the legal 3.7mph.

 

Yosepower instructions below:

 

Engwe instructions further below::

 

[ATTACH=full]62919[/ATTACH][ATTACH=full]62920[/ATTACH]

I think you're misunderstanding the point of discussion. Chris_n said that 6km/hr isn't supposed to be used for start assist, but the law specifically mentions that it is. That's where he's incorrect, along with Peter, Woosh and Neal, who agreed with him.

 

Anybody can do what they want within the law. If a manufacturer wants to have a walk assist button, that's up to them. The law says you can have 6km start assist and use it for walk assist if you want. That's what Yose have done, according to them, though I suspect that they just included that feature because nearly everybody else has it, then they figured out that their implementation method doesn't provide enough power for inclines with the rider on the bike. If you try it as a walk assist, you'll probably find that it's useless at that too. 6km/hr is too fast for walk assist. It needs to be about 2.5 to 3 mph.

I think you're misunderstanding the point of discussion. Chris_n said that 6km/hr isn't supposed to be used for start assist, but the law specifically mentions that it is. That's where he's incorrect, along with Peter, Woosh and Neal, who agreed with him.

Chris_n said:

 

The 4mph thing is designed to be an aid when you have to push the bike, that's why it is called walk assist. It usually only has a low power output and is not meant to allow you to start without pedalling.

 

Chris_n is correct. You can sit on the bike and press the walk assist button but it is not how it is meant to be used.

That's what I agreed with.

If I need a push to start from standstill, I would use a throttle.

I still do not think that limiting the voltage of the throttle to something like 2V-3V is a good idea. You cannot control the acceleration and speed limit with this method.

Chris_n said:

 

 

 

Chris_n is correct. You can sit on the bike and press the walk assist button but it is not how it is meant to be used.

That's what I agreed with.

If I need a push to start from standstill, I would use a throttle.

I still do not think that limiting the voltage of the throttle to something like 2V-3V is a good idea. You cannot control the acceleration and speed limit with this method.

You're changing the story. Comments were in relation to what Bobbo did, not any general situation. Read back through the thread.

You're changing the story. Comments were in relation to what Bobbo did, not any general situation. Read back through the thread.

Bobbo didn't do much. The title of the thread 'Making a torque throttle' is misleading but the gist of what Bobbo tried to do is sufficiently clear. It's about how to meet the 6km/h throttle when the firmware wasn't programmed for it. I would do that by generating a brake signal when the speed reaches 6km/s.

Edited April 23, 20251 yr by Woosh

My method may be somewhat crude but serves the purpose of giving me a throttle that is limited to a legal 4mph limit.

If Woosh knows a better means of achieving my aim then please share, providing I don’t have to do any electrical calculations. Splicing and soldering I'm ok with though.

My method may be somewhat crude but serves the purpose of giving me a throttle that is limited to a legal 4mph limit.

If Woosh knows a better means of achieving my aim then please share, providing I don’t have to do any electrical calculations. Splicing and soldering I'm ok with though.

My view on this is explained in my Post #21, Post #35 and Post #58.

To do this in hardware, you will need an arduino and some programming.

This method will let you control acceleration, your starting off will be exactly the same if the throttle wasn't restricted.

Edited April 24, 20251 yr by Woosh

Hi woosh,

My electronics knowledge is very limited to the extent that I had to look up what an Arduino is which brought me to the conclusion that this is well outside of my skills.

Thanks for the links anyway.

Hi woosh,

My electronics knowledge is very limited to the extent that I had to look up what an Arduino is which brought me to the conclusion that this is well outside of my skills.

Thanks for the links anyway.

Using google to look up arduino is the only skill needed to learn..

 

The #1 Super thing about the arduino framework is that EVERYTHING you can plug into the arduino has its own working example program (in arduino-speak a program is a 'sketch') - And these example programs/sketches are laid out with comments/instructions to teach you about how to use them..

 

So programming becomes a task of finding all the example sketches for the h/w needed for your project, and using the cut and paste editing features to build your program from the building blocks of the examples..

 

Yes there is more too it - its called programming, but with a lot of the hassle and hard work already done for you leaving you to to stitch the relevant copied blocks together with common variables etc.. So an evening reading the first few chapters of any C primer will get you going.

 

Start with just a bare £2 arduino uno clone and the blink sketch and if that makes sense to you - the sky is the limit..

 

 

If it rings your bells there's a lot more toys out there to play with too.. esp8266/32 devices, tasmota and node red are some of my favourites..

Using google to look up arduino is the only skill needed to learn..

 

The #1 Super thing about the arduino framework is that EVERYTHING you can plug into the arduino has its own working example program (in arduino-speak a program is a 'sketch') - And these example programs/sketches are laid out with comments/instructions to teach you about how to use them..

 

So programming becomes a task of finding all the example sketches for the h/w needed for your project, and using the cut and paste editing features to build your program from the building blocks of the examples..

 

Yes there is more too it - its called programming, but with a lot of the hassle and hard work already done for you leaving you to to stitch the relevant copied blocks together with common variables etc.. So an evening reading the first few chapters of any C primer will get you going.

 

Start with just a bare £2 arduino uno clone and the blink sketch and if that makes sense to you - the sky is the limit..

 

 

If it rings your bells there's a lot more toys out there to play with too.. esp8266/32 devices, tasmota and node red are some of my favourites..

An arduino would have been way over the top for what he wanted. He solved his problem with a £0.12 preset and two wires. Why would you want to make it more complicated than that?