Can anyone help me adding a throttle to a carrera crossfire e bike please

Major009

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Oct 27, 2023
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Hello you wonderful people I have recently brought a carrera crossfire e bike from halfords and was wondering if anyone has any information how to add a throttle to the bike would it be as simple as replacing the controller and display. Please help I'm a novice here many thanks
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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Any extra work in the two year warranty will void said warranty.
Surely would be better to buy a used cheaper bike.

Your battery has two year warranty and the bike one year , if the battery, TS goes wrong or the hub has a fault you will be stuffed by changing or modding the bike.
 
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saneagle

Esteemed Pedelecer
Oct 10, 2010
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Hello you wonderful people I have recently brought a carrera crossfire e bike from halfords and was wondering if anyone has any information how to add a throttle to the bike would it be as simple as replacing the controller and display. Please help I'm a novice here many thanks
There are different versions of your bike, which need different solutions, and they're changing all the time. I agree with Neal. The easiest solution is to sell it and buy or make a bike like you want it.

If you know anything about electronics, the controller responds to two signals. A high frequency pulsing signal indicates that the pedals are turning and a 0v to 5v signal tells it how hard you're pedalling. All you need to do is put a pulse on the pulse wire, then you can use a potentiometer as a throttle. You can buy those very cheaply on Ebay.
 

Saracen

Esteemed Pedelecer
Aug 24, 2023
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UK ILLEGAL 100% unless on PRIVATE land (you own or similar) off roading does NOT count if others use it, you can get 6 points on your car licence and god help you if you are ever in an accident, someone's hort, you cause damage and it is seen you have one, if you doubt it ask the Police, call them don't take my word for it.

What class do “twist and go” throttle ebikes belong to?
It could be complicated. Here we go: since January 1, 2016, the only throttles legal within the EAPC legislation are those that assist the rider without pedalling up to a maximum speed of 6 km/h (3.7 mph) – i.e. starting or walking assistance only. If the rider is rolling – but not pedalling – faster than 6km/h, the throttle must cut off.



In other words, "walk assist"
 
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Nealh

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Aug 7, 2014
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A throttle use depends on how it is configured to be used, illegal if twist and go without pedalling. if a throttle ceases to work when not pedalling then it isn't ilegal.
Legal as twist and go if only propelling the bike up to 6km/h walk assist.
 

Major009

Just Joined
Oct 27, 2023
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Thank you for the replies I appreciate it. I'm not very good with electronics in such so I have some learning to do before I get down to business. I have listed it up for 800 quid last price and had no interest at all and I can't afford a new bike just yet as money is tight by Xmas but I hope all your advice will guide me the right way. Many thanks all
 

Alsimms

Finding my (electric) wheels
Apr 9, 2024
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2
There are different versions of your bike, which need different solutions, and they're changing all the time. I agree with Neal. The easiest solution is to sell it and buy or make a bike like you want it.

If you know anything about electronics, the controller responds to two signals. A high frequency pulsing signal indicates that the pedals are turning and a 0v to 5v signal tells it how hard you're pedalling. All you need to do is put a pulse on the pulse wire, then you can use a potentiometer as a throttle. You can buy those very cheaply on Ebay.
Hi, I want to do this modification so my question is how do i put how do put a pulse on the pulse Green and Blue wires on the battery connection please?. TIA.
 

saneagle

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Oct 10, 2010
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Hi, I want to do this modification so my question is how do i put how do put a pulse on the pulse Green and Blue wires on the battery connection please?. TIA.
 

Alsimms

Finding my (electric) wheels
Apr 9, 2024
11
2
Thank you for the link :). I have ordered one off Fleabay. I can use a soldering iron. Could you tell me or do you have a wiring diagram or is it self explanatory when it arrives.
cheers.
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
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Thank you for the link :). I have ordered one off Fleabay. I can use a soldering iron. Could you tell me or do you have a wiring diagram or is it self explanatory when it arrives.
cheers.
It's a long time since I checked, but IIRC, there are 4 wires on the torque sensor connector. They're 5v, ground, pulsing 5v, and 0-5v analogue. You need to test with a meter to see which is which.

The sensor is optical and has its own electronics. There are two over-lapping castellated anular rings, one fixed to the chainwheel and the other to the pedal so that when you put force on the pedal, the torque moves one castellated ring relative to the other so it has the effect of shortening the gap between the castellations. In other words the electronics sees pulses of light through the gaps in the castellations. The frequency indicates the pedal speed and the pulse length indicates how hard you're pedalling. Those two vales are converted into the above outputs.

The 5v and ground can be spliced to the frequency generator to power it, and its output goes to the pulsed wire. You'd have to experiment to get the right frequency, but I'd say something like 60 rpm pedal speed x 40 to 60 castellations would be somewhere around 2400hz to 3600hz.

The throttle would be powered by the 5v and ground wires, and it's output would go to the analogue wire.

I've never tested that this works, but I'd give it a better than even chance. Somebody needs to be a hero to risk a few quid to try it.

You can buy the connectors from Ebay. I can't remember what they're called. I just typed in 4-pin connector and looked at the pictures until I found them.
 

Woosh

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May 19, 2012
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Southend on Sea
wooshbikes.co.uk
Hello you wonderful people I have recently brought a carrera crossfire e bike from halfords and was wondering if anyone has any information how to add a throttle to the bike would it be as simple as replacing the controller and display. Please help I'm a novice here many thanks
you need pretty good soldering skills and understanding of electronics to do this. Basically, you unplug the cable between the pedal / torque sensor and the controller, add an arduino kit in series between the sensor and the controller. The arduino receives the power from the controller and pulses from the sensor, plus the input from a throttle, then computes the results and outputs its pulses to the controller. This system has been successfully implemented by three members in the past.
 

Alsimms

Finding my (electric) wheels
Apr 9, 2024
11
2
Hi , thank you for your reply. What i was hoping to do was use the Carrera battery which has the two pin one green and one blue wires that goes to the sensor. I want to do away with the sensor and implement a throttle only. So i need something to send a signal to down the said two pin connection to keep the battery "alive" as without it the battery just shuts down after the bike has travelled a few feet without it.
It would be easier to use another battery, but the bike is a Volt Pulse that uses a very slim line battery that fits behind the down tube but they are mega bucks new and i can't find a silver fish type battery that is of the correct dimensions (9 x 9CM'S) the length is not critical. There is some e batteries on Ali express but they won't send them to the UK.
 

saneagle

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Oct 10, 2010
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Hi , thank you for your reply. What i was hoping to do was use the Carrera battery which has the two pin one green and one blue wires that goes to the sensor. I want to do away with the sensor and implement a throttle only. So i need something to send a signal to down the said two pin connection to keep the battery "alive" as without it the battery just shuts down after the bike has travelled a few feet without it.
It would be easier to use another battery, but the bike is a Volt Pulse that uses a very slim line battery that fits behind the down tube but they are mega bucks new and i can't find a silver fish type battery that is of the correct dimensions (9 x 9CM'S) the length is not critical. There is some e batteries on Ali express but they won't send them to the UK.
The two wires don't go to any sensor. They're for communication with the controller. Without the communication, the battery won't give power. If you want to keep the battery, you need to change the BMS inside it to a dumb type.
 
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Alsimms

Finding my (electric) wheels
Apr 9, 2024
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Hi, thankyou. The next question is how easy is it to replace the BMS and is it worth doing?.
If anyone has a Carrera vengeance I'd be interested to know what signal/pulse /voltage etc is transmitted down the green and Blue wires to keep the battery active.
 
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Woosh

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May 19, 2012
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The next question is how easy is it to replace the BMS and is it worth doing?
you should not attempt to open your battery.
 

saneagle

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Oct 10, 2010
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Hi, thankyou. The next question is how easy is it to replace the BMS and is it worth doing?.
Like everything, it's easy when you know how. Basically, you have to solder a connector to about 10 wires and solder two or three others to a PCB. Only you can judge if it's worth doing by evaluating it against alternatives.
 

Alsimms

Finding my (electric) wheels
Apr 9, 2024
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Ok cheers, as I've upgraded everything on my Carrera vengeance E I think I'll just sell all the motor, battery, controller etc, etc and buy another battery for the project.
 
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saneagle

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Oct 10, 2010
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Ok cheers, as I've upgraded everything on my Carrera vengeance E I think I'll just sell all the motor, battery, controller etc, etc and buy another battery for the project.
Have you changed the motor. If so, can you give details of how?