Cmacewheel GW20 P.A.S. Problem

[brian78]

I recently had to replace the rear hub motor. On my Cmacewheel GW20. Soon after the pedal assist became intermittent then stopped altogether. I thought I diagnosed it as the pas sensor and changed it.

Still nothing.

Then I thought I had traced it back to a broken wire leading into the control unit. So I replaced the control unit. And still no pedal assist. I'm losing my mind over this bike as I need it for commuting to work

Could someone please help me to diagnose this really annoying problem.

Many thanks

 

[Benjahmin]

Going to need a bit more detail Brian.
Is the pas sensor the one with a seperate disc? If so is the disc within a couple of mm of the sensor head? Does it run parallel to the head? Does the disc turn with the shaft? As the magnets pass the sensor does the led flash?
Do you have a throttle? If so does that still work?
A photo of the bike, it's controller, display and pas sensor would help.

 

[saneagle]

I recently had to replace the rear hub motor. On my Cmacewheel GW20. Soon after the pedal assist became intermittent then stopped altogether. I thought I diagnosed it as the pas sensor and changed it.

Still nothing.

Then I thought I had traced it back to a broken wire leading into the control unit. So I replaced the control unit. And still no pedal assist. I'm losing my mind over this bike as I need it for commuting to work

Could someone please help me to diagnose this really annoying problem.

Many thanks

You probably didn't push the motor connector far enough. Why did you have to replace the motor?

 

[brian78]

You probably didn't push the motor connector far enough. Why did you have to replace the motor?

 

[brian78]

The reason the motor was replaced was that the hub needed respoked. And the motorcycle shop who did that ruined the motor in the process ( dont ask me how) that's what started the whole problem off. So I as I said the bike wouldn't work at all. And changed the motor . That's when the pas became intermittent. So I thought I'd change the pas sensor. ( yes I took it apart and examined it,cleaned it).

Still nothing. I then thought I'd diagnosed it to a broken wire leading in to the control unit so I've replaced that and still nothing

This is the original pas sensor. It's all one unit. Sorry about the photo

 

[Nealh]

Those one piece PAS sensors can be problamatic , you would have been better to use a two piece sensor set up.

 

[saneagle]

Looks like you have some bad luck. When an ebike doesn't work you find out what's wrong by testing and measurement, then you know what you have to fix. If you have block connectors at the controller end, it's easy to test with a meter. Sealed connectors make it more difficult. For them, you have to make adapter leads so that you can get at the wires.

Before testing anything, it's wise to check all the connectors, the motor one gives the most problems because it can be in tight but still not far enough. In that case, not only does it make the motor intermittent, but it can blow the controller. Likewise with the motor connections at the controller end, especially the bullet-type connectors that can be in, but not tight enough.

Those all in one pedal sensors give lots of problems, and could easily be the cause of your intermittent running. To find out, you either check what voltage you get on the signal wire while turning the pedal very slowly and/or you take the pedal arm off and watch what happens to the middle part. If it works with the pedal off, it was getting squished by it.

Does your controller have a throttle connector? Replacing the controller brings a whole load of potential new problems. Did you get the manufacturer's replacement one or another one?

 

[brian78]

I've been in contact with a sales advisor at Cmacewheel and hes going to wait till Monday to speak with a technician. I've checked out the wiring loom and everything appears fine. I bought the same sensor as it was the only one that had the same connections.

The hub motor came from Ebay as did the sensor but the control unit came from the Cmacewheel website.

The bike works fine in throttle mode. But its severely affecting my mileage as I use the bike for commuting

 

[brian78]

Albeit. I took the bike out today, and on several occasions, the pedal assist kicked in. But only for a second. It did that a few times but never stayed on

 

[saneagle]

Albeit. I took the bike out today, and on several occasions, the pedal assist kicked in. But only for a second. It did that a few times but never stayed on

Was that with the bike in it's present state? You info is all over the place. You're trying to shoot a moving target. Every time you change something, it can bring new problems. It's difficult to figure out what your saying applies to what.

 

[thelarkbox]

Albeit. I took the bike out today, and on several occasions, the pedal assist kicked in. But only for a second. It did that a few times but never stayed on

not a very well informed guess but if you have a new controller its possibly not set up for your motor but the stock motor supplied usually? Since your motor came from ebay its possibly not exactly the same as what its replacing. assuming you got the controller from the bike supplier?

If i am not shooting wide a competent tech should be able to sort out the ?geometry? of your motor, if not you may need to google you motors specs and controller guides

 

[brian78]

That's it in its present state.
New control unit
New pas sensor
New motor.

 

[thelarkbox]

The bike works fine in throttle mode.

- I missed that scrub what i said above,

 

[brian78]

I'm not tech savvy when it comes to electronics. But I am starting to believe that the hub motor may be the problem. I still have the original motor and plan on send the serial number to Cmacewheel technicians and details of the new motor to them also.

I was looking at the new hub motor earlier and there is absolutely no technical information stamped/engraved on it at all. Just a bare motor. So I bought it with the honest intention that the seller was genuine with the information they put up on the ebay page.

Just for everyone's information the bike is

750watt
48volt
&a 15ah battery

 

[saneagle]

Please verify whether these facts are correct, which is the best I can get from you've said. This only applies to the present setup:
1. It works fine with the throttle.
2. It has worked intermittently with the pedal sensor.
3. At one point it was working fine with the pedal sensor.

 

[brian78]

Correct
Works fine with throttle.

Was 5/6 times only with pedal sensor ,and only just for a second each time(that was when I took the bike out yesterday)

And now nothing

No pedal assist at all.

The pedal assist problem only arose when I changed the motor. So with different conversations I have had with different people. I'm starting to believe that the new motor may in fact be the cause.

 

[thelarkbox]

Most odd and must be very frustrating, everything has been replaced!

Having looked at a replacement controller myself i have done a little browsing up and watching of utubes on the subject nothing saved so i cant give a link but google is great once you get past the ads.

the common start of most how to's is generally go to x settings page of your current controller and write the value down.. this relates to your motor specifically...

Again very limited experience but after looking at the KT controller and headset options the headsets often have 2x manual pdfs available the first a 1-2 page or so basic settings (UK/EU approved manual??) and the second generally found on chinese sites a 10+ page document detailing all advanced config settings..

a google for "YOUR_CONTROLLER_ID/MODEL_#" + " 750w motor config settings how to" or "tuning"

Might be fruitful? going by past experience of earlier projects ive undertaken Im pretty sure it will take you down a rabbit hole needing to look up things as they turn up recursively. and be quiet the pita... but once you start following the right breadcrumb trail it may start to make a lil sense?


BUT WHAT IS VERY CONFUSING to me at least is the throttle works??
I have a black box appreciation of electronics, i can understand a controller not sending the correct sequence pulses for the motor due to a config issue..

ahhh???

when throttling i bet you twisted it upto full and i bet your pedal assist is slow start, and the slow start wont kick the motor round but at full throttle it jumps into line.. or thats how my limited grasp of how it kinda all works..

try changing pedal assist to fast start?

 

[saneagle]

The problem can only be caused by the pedal sensor. It must be jamming or slipping. take the pedal off and watch what happens to the middle bit while you turn the pedal.

 

[brian78]

Sorry!! Work issues meant I was busy with a lot of stuff .

Pedal sensor appears 100%. Turning on the crank perfectly

When I'm using the throttle. That's all I have, throttle. Let go of the throttle. And its leg power only. NO PEDAL ASSIST

It's either a REALLY heavy regular bicycle, or an electric moped. Theres no inbetween. No pedal assist at all. Doesn't power up slowly (doesn't power up at all).

But as I said this problem only arose a soon as the new motor was fitted. So I'm going to try the rabbit hole and start with Googling the control unit and see how deep I go

 

[saneagle]

Sorry!! Work issues meant I was busy with a lot of stuff .

Pedal sensor appears 100%. Turning on the crank perfectly

When I'm using the throttle. That's all I have, throttle. Let go of the throttle. And its leg power only. NO PEDAL ASSIST

It's either a REALLY heavy regular bicycle, or an electric moped. Theres no inbetween. No pedal assist at all. Doesn't power up slowly (doesn't power up at all).

But as I said this problem only arose a soon as the new motor was fitted. So I'm going to try the rabbit hole and start with Googling the control unit and see how deep I go

On the pedal sensor connector there are three wires - red, black and another one that's the signal wire. Straighten two paperclips and put one end of one in the signal wire and one end of the other in the red one. With rhe wheel off the ground and everything switched on, rapidly tap the free ends together. If the wheel turns, stop, otherwise move the paperclip from red to black and repeat.

If either of those tests make the wheel go, there is a problem with the pedal sensor - broken or incorrect wire sequence. If the wheel doesn't turn, the pedal sensor is switched off in your controller settings.

Simple test. Simple logic. Simple solution.