!!!!! HELP me with my 26" Bafang Rear Wheel Build please !!!!!
- Thread starter bilabonic
- Start date
Cheers, i have seen people add switches etc to brakes, seen micro's and proxy limits glued in place, is this what your referring to ?Just hold onto the brakes.
I have just bought a 24s lipo BMS, from what I have read I can add a micro switch to the BMS and run it up to the handlebars; should allow me to complete cut off the main power supply
I thought a BMS was a charger - Battery Management System ??
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Personally, i wouldn't trust the throttle alone to stop the motor. I have had a ground wire break, a capacitor s/c in the controller and a magnet pop out of throttle. All these situations led to the motor running on it's own. You may be able to stop it with the brakes but by the time you realise somethings wrong you could easily have a tumble.
If you are running a BPM and many volts i think it's essential to have an ebrake of some type.
If you are running a BPM and many volts i think it's essential to have an ebrake of some type.
D
Deleted member 4366
Guest
I have to agree. I've had two throttles break when I went over a bump at full throttle. The result was that the bike ran on it's own because you need the low throttle magnet against the hall sensor to get zero throttle. No magnets = half-throttle. I was able to ride home by using the brakes to cut the throttle when I wanted to go slow. You can stop the motor with the brakes, but you'll blow the FETs in your controller very soon after.
I tried a bike with no brake switches that had one of those pedal sensors that make the motor run on for about two seconds. The brakes, which were normally quite good, hardly stopped me when fighting the motor. It wasn't very comfortable!
Oh, i presumed the throttles were resistance based and totally variable, so it s stop, mid, and full.
Thought the three connections were GND, Variable Input and Power.
I agree for pedelec, I prefer one cutout brake for the short run on that often occurs when you stop pedaling.
Also like one for throttle only when I have cruise control
Jerry
Also like one for throttle only when I have cruise control
Jerry
D
Deleted member 4366
Guest
No, the signal is continuous and variable. Most Chinese throttles work like this although you can get other types of throttle and different hall sensors:
The hall sensor in it in its natural state (no magnetic field) gives out approximately 2.5v, which is half- throttle signal. There are two magnets either side of the hall sensor. One is north facing and the other's south facing. As you bring the north facing one to the sensor, the increasing north magnetic field drags the voltage down to about 1v, which is the zero throttle signal, so the throttle spring holds that magnet against the sensor in the stop position. As you open the throttle the north magnetic field gradually decreases, so the voltage increases. Once you get past the half-way point, the south magnetic field gets stronger, and it causes the voltage to increase from the sensor until the magnet's against it, when it gives a signal of about 4v for max throttle.
The magnets are only held in thin plastic, and the physical throttle stops are also thin plastic, so throttles are easily broken, though some are stronger than others.
Well i'm off to a bad start re the brakes, went to remove the resevoir covers (both were seeping fluid) and noticed all T15 bolts rounded !!
Managed to to remove them by hammering in larger T20, think they are just 2.5mm threaded/8mm long so should find a replacement.
The PROBLEM lies that one of the rubber diagrams has split !!! The brake had no pressure since purchasing bike.
Part No - 120071056
Been googling to find a spare BUT not looking promising.....I have also mailed Clarks who i suppose after much reading will direct me to suppliers who can not source the part !!!
Managed to to remove them by hammering in larger T20, think they are just 2.5mm threaded/8mm long so should find a replacement.
The PROBLEM lies that one of the rubber diagrams has split !!! The brake had no pressure since purchasing bike.
Part No - 120071056
Been googling to find a spare BUT not looking promising.....I have also mailed Clarks who i suppose after much reading will direct me to suppliers who can not source the part !!!
... I know the feeling ... when you start working on the mechanics of a 2nd hand bike you just never know what you're going to find and it's tough finding like-for-like replacements for older parts sometimes.I saw this recently though - you need an in-line cutoff switch for the rear brake but the package is pretty incredible value provided you don't mind dual-controls - and you get brand new disc brakes and gear shifters for £80 :
Shimano XT M765 Dual Control Disc Brakes | Shimano Disc Brakes | Merlin Cycles
Lots of deals around for substitutes like this on other levers but this is a complete system and incredible value. It's for 3 x 9sp so should be compatible with Kraken ... I think the SRAM cassettes and derailleurs are OK with Shimano shifters.
LiPos scare the living daylights out of me. Every time I read about them I feel a bit like I'd be shacking up with a suicide bomber
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D
Deleted member 4366
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Rule no.1 when making an electric bike from a kit: Always check the polarity with a meter before connecting anything - even if they have matching connectors.
Rulle 2: Don''t take any notice of colours. It's not unusual for the Chines to use blue for "+" and brown for "-".
When you connect your controller with the correct polarity, you still get a big flash and a bang, which can be enough to damage connectors because the KU123 has large capacitors that charge instantly when you make contact, so don't panic as long as polarity is correct. Afrer a few connections, youur nerves become stronger, and connection becomes easier. Don't worry, you can't electrocute yourself from it.
If by chance you did connect with wrong polarity, your controller is an ex-controller - not just pining for the fjords, in which case I might be able to help you out with a new one.
Edit: I see, you've got lipos. You have to work out the logical connections very carefully. Your leads look OK to me. How much did the connector melt? It could still be the controller capacitor causing the spark if it's superficial, otherwise you need to check the leads with a meter.
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Yes Plugged one group 3 in then when i plugged other group of three in it melted the connector.
I'm used to flashes/sparks mate, i'm an industrial sparky by trade upto 11Kv.......
Just did not expect it with all FETS not firing.
Which colours are the throttler as the colours do not up mine on controller.
I have two 3 pin plugs -
blue-black-green
red-black-green
Connected them up individually this time and have 50.1v at controller.
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D
Deleted member 4366
Guest
Red black and green is the throttle. I think that the connector's the other way round on the 3-speed switch, isn't it?
The spark and bang you get when you connect the controller to 50v is not like anything else you''re likely to experience as a sparky.
So, are you saying that it was just the spark from the controller, or is something else wrong?
Ideally, you need a pre-charge resistor on your connection because the spark will erode your connectors eventually.
The spark and bang you get when you connect the controller to 50v is not like anything else you''re likely to experience as a sparky.
So, are you saying that it was just the spark from the controller, or is something else wrong?
Ideally, you need a pre-charge resistor on your connection because the spark will erode your connectors eventually.
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