City hopper throttle

Hightechpete

Pedelecer
Jan 20, 2018
151
33
72
west Wales
Hi all, trying to help a friend install a throttle to his Tesco city hopper as he has mobility problems and can't always peddle.

This bike has a pedelec system which works fine, but has no led/lcd control, it seems to be permanently on a mid range level of assist. The thumb throttle arrived today and was fitted into the only available 3 wire connector (yellow/black/red) - throttle is not working. I'm getting close to 5v on the red wire and about 4v on the signal wire when throttle is activated, so I'm assuming that everything is working as it should.

I'm wondering whether it has something to do with the lack of an lcd/led.
My cyclotricity kit on throttle only needs either an lcd or a plug which connects the wires that would normally go to the led. Could this be the same, would I need to short the connections on the plug which would normally power the led?
Or is there there some other reason which I'm not aware of ?.

Pete.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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4v when throttle is open is right, are you sure the connection is for a throttle ?
Have you checked the closed position where on Signal /Gnd you should see 1v.
Could it be for a speed sensor ?
 
Last edited:

Hightechpete

Pedelecer
Jan 20, 2018
151
33
72
west Wales
Thanks for the reply Neal, I've been browsing and searching for a while and found an earlier reply from you regarding the Viking eco, as far as I can tell it's the same bike (has the same controller), so yes I'm pretty sure it's a throttle connection. I'll check for the 1v in closed position tomorrow.
Your previous reply :-
Apr 14, 2017



Pics are very poor :eek: and make viewing on the eyes uneasy..
The last one 4 pin is a data cable for programming forget that. If you only have those other two then you need a 3 wire/pin connector.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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Basildon
The controller needs to see a zero throttle signal before it'll give power with the throttle, so switch the bike on with the throttle disconnected, lift the wheel off the ground and see whether the wheel starts turning.

Also, check that the red goes to the red, black to black and signal to signal because there's no standard for the sequence of the wires in the connector.
 

Hightechpete

Pedelecer
Jan 20, 2018
151
33
72
west Wales
The controller needs to see a zero throttle signal before it'll give power with the throttle, so switch the bike on with the throttle disconnected, lift the wheel off the ground and see whether the wheel starts turning.

Also, check that the red goes to the red, black to black and signal to signal because there's no standard for the sequence of the wires in the connector.
Red goes to red, black to black, signal wire is white to yellow, I don't understand the first part, could you re-phrase it?
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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When you switch on the bike and there's a non-zero throttle signal, the controller ignores it and will continue to ignore all throttle signals until it sees zero once, after which it'll respond to whatever signal it gets. It's a safety feature to make sure that your bike doesn't ride off without you on it as soon as you switch on, like when a throttle gets a bit stuck or when the end-stop gets broken.

FYI, the sensor gives a half-throttle signal (3V) when it's on its own. Its output is influenced by magnets. In the throttle are two magnets. When one (N-pole)comes to the sensor, it pulls the signal down to zero, and when the other (S-pole) comes to it, it pulls the signal up to max. It relies on plastic end-stops to get the magnets in the right place. If you break the end-stops, which are only thin plastic, the magnets go past the sensor and so zero throttle becomes say 1/4 throttle and full twist goes past max and then back down again. If you crash and break the throttle or bash it too hard, the magnets can get broken off, so they have no effect on the sensor and you end up with the throttle stuck on half max speed.

In the full throttle position, you get around 4v, and 1V in the zero position. Anything below about 1.3v counts as zero throttle as far as the controller is concerned..
 
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Hightechpete

Pedelecer
Jan 20, 2018
151
33
72
west Wales
Thanks VFR, understood. Just to be sure the controller was seeing zero volts I disconnected and reconnected the signal wire with the power on - still nothing. All voltages check out i.e 5v between red/black, 1v between black/white (throttle closed) 4v full throttle.

My extensive research has revealed the following, the bike in question city hopper aka viking ego had a display as an optional extra. Those who have the display have successfully installed a throttle. The one post I could find of an unsuccessful attempt had no display. It looks as though the easiest option would be to fit a compatible display, then I'm hoping everything will be fine.

Link to controller photos :-https://www.pedelecs.co.uk/forum/threads/remove-15mph-speed-limiter.15449/post-190049

Thank you for your indulgence, any further advice would be welcome.

Pete.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
19,988
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Test whether the throttle works when you're pedalling.
Good point, regulation means new bikes after 2016 are programmed to only work on throttle once the pedals have been rotated (could be as little as 1/2 roatation).
 

Hightechpete

Pedelecer
Jan 20, 2018
151
33
72
west Wales
Test whether the throttle works when you're pedalling.
Nope, rather defeats the object anyway. Friend suffered a stroke and needs a throttle to get him home when his leg stops functioning, he can't walk very far. But he finds the gentle exercise helps his condition somewhat.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
19,988
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Nope, rather defeats the object anyway. Friend suffered a stroke and needs a throttle to get him home when his leg stops functioning, he can't walk very far. But he finds the gentle exercise helps his condition somewhat.
You need yo dump the Lishui or whatever it is and fit a KT with a simple lcd1 or 2 if you want throttle only.
 

Hightechpete

Pedelecer
Jan 20, 2018
151
33
72
west Wales
Thanks Neal, he's not averse to spending a little to achieve what he wants.
One more question while I'm here, are the non-julet connections to the controller standard for all controllers, or will they have to be changed to suit?.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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As vfr has stated you will have to look at the PSWPower controllers page, click the correct thumb nail for a close up of the wiring order and connector used. Their is little in the way of standardisation between manufacturers, even with Julet some sellers fit opposing/male /female connectors to try and keep business.
A KT upgrade/change will be in the region of £75 - £100.
 

Hightechpete

Pedelecer
Jan 20, 2018
151
33
72
west Wales
Further to previous replies, a new brainpower controller and an s866 lcd have been fitted, a bit of a bargain at £28 complete. After much faffing around with P settings and new male/female plugs everything has been fitted (correctly I think). Throttle to black/red/white, PAS to black/red/blue. Here's where I'm at :-

Brake switches operate correctly.
LCD shows correct speed.
Throttle works fine, but only gives full power when PAS is set to 5.
PAS works but only gives very low power regardless of PAS setting.
Permanent error code 07 (motor failure).

Here's the weird thing, if the bike is wheeled backwards (pedals not turning), the motor will suddenly engage and surge forward.
I've read all 14 pages of the Brainpower/LCD 866 post but can't find any solutions, does anyone have a clue as to what's going on?.

Perhaps I should mention that the bike is virtually new and all connections to controller and motor double checked.
 

Hightechpete

Pedelecer
Jan 20, 2018
151
33
72
west Wales
Thanks for the speedy reply Vfr, I'll double check everything tomorrow. It's almost as if the throttle and PAS connection have been crossed, but if that was the case surely neither would work?.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,985
Basildon
Thanks for the speedy reply Vfr, I'll double check everything tomorrow. It's almost as if the throttle and PAS connection have been crossed, but if that was the case surely neither would work?.
The PAS would give a pulsing 5V, which would be the same as a low throttle signal except if you stopped the crank in the wrong place, when you'd get full throttle. I've seen connectors crossed before that give weird effects like you've got. a common one is connecting the throttle to the speed sensor connector because both are often red, white and black, whiles as the controller's throttle connector is red green and black or similar.
 

Hightechpete

Pedelecer
Jan 20, 2018
151
33
72
west Wales
Thanks Vfr, you were right. I think the signal and +ve wires on the PAS connection were crossed. Thinking about it, it makes sense. The back EMF generated by rolling the motor backwards would send a signal similar to turning the pedals? of course this could be complete bollarks.
Temporary connections have been made and things are looking good.

I still have the E07 error, and full power throttle is only achieved when PAS is set to 5, but neither of these are dealbreakers. Thanks again - Pete.
 

Hightechpete

Pedelecer
Jan 20, 2018
151
33
72
west Wales
A quick update on the above, it was felt that the existing setup was a little feeble for his needs. We upgraded to a 36v battery, the no load speed is now 23 mph and it'll smoke the front tyre.
I warned him that the bike was now technically illegal, he said, and I quote, 'They can kiss my a**e'. Love it.
 

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