PAS backwards - how to flip?

My right side PAS broke and I had to get a new one. Ended up buying two new PAS with magnet disks from two different online shops, still waiting on the "correct" right hand KT-D12R to arrive. In the mean time the supposed right hand PAS arrived and after shortening the cable and fitting female JST connector supplied by the shop, I was finally able to test the PAS. Here is the link to the PAS page on shop website: https://www.rat-holland.nl/Onderdelen/Overige/P.A.S.-sensor-set-deelbaar.

Well it turns out the PAS worked correctly - but only pedaling backwards. It is obvious that the PAS is for the left hand side since flipping the magnet disk does not change anything, PAS only senses rotation in certain direction. Now I tried flipping the PAS itself and I can get it to sense the correct rotation but just barely and I had to remove the part that allows it to attach to the frame. So now I know that the PAS is for the left hand side but ...

Is it possible then to simply flip the sensor by flipping the PCB? Meaning, if I open up the sensor, remove the potting, extract the PCB then simply flip it 180 degrees, will it work reliably? I do not know the layout of the PCB and the hall sensors and whether simply flipping the PCB will be enough to allow for correct and repeatable signaling. Does anyone know if this will work? This sensor was labelled as "King Meter" and on the disk it says SNH2. I figured out this is the King Meter SSP-DH sensor and it is definitely left hand sensor.

I would appreciate it if anyone can confirm this will work before I remove the potting. Currently the sensor works perfectly for left side and I don't want to destroy it or damage it unless I am sure it will work on the right side. The other sensor that will arrive is definitely for the right side so I am sure it will work but I would like to have a backup so I would modify this one if it is possible. Thanks ahead of time.

just turn the magnet disc over so that the north and south poles are reversed. ,,,,simple

Jonno

That doesn't work. PAS only senses in one direction, doesn't matter how the magnet disk is oriented. I have tried and tested it.

Oh.....it always work for me and I've built loads

Jonno

I flipped two of the wires, ill try to find the one I did to see wich wires I flipped. theres a signal. example, 010101 but if on wrong side you get 101010. I flipped 2 wires to make it 010101 again

cant find the one I switched but I found another one like yours and flipping the wires aren't working

It will not work by flipping any wires. There are only 3 wires: +5V, GND, Signal. Either way, the Signal wire carries the pulses and the pulses are only activated by spinning one way. Spinning the other way the signal remains at either 0V or 5V (don't know which one but remains at one level).

I decided to remove the potting and flip the PCB. The two hall sensors are soldered on PCB such that the sensors are closer to the magnet disk when sensor is positioned "correctly". So once I flip the PCB, the sensors will be further away but as long as I keep the bottom of the PCB within 5 mm of the magnet disk, it still should work. I tested it last night with just bare PCB (not installed in any housing) and the controller sensed the PAS when I pedaled forward (and didn't sense when pedaling backwards).

So now that I verified that it works, I just need to put the PCB in some housing that will protect it and still be close enough to the magnet disk. I will probably use the original housing but flip the PCB and push the part with hall sensors close to the wall of the housing. I will pot everything again and close the housing.

You have it on the right (crank) side, and it only works when pedaling backward. Ah, it will work on left side pedaling forward. No room on the left side?

I think most of my PAS units are these red plastic versions. KT V7-50. These indeed will only work backwards if the disk is reversed. Meanwhile, they change the design of the sensors and don't tell Jonno and me.

OP has a handed PAS, which will only work on one side in one direction. The only way to reverse direction with one of those is by software in the controller, and AFAIK, only KT controllers have that. If you have a KT controller, it's parameter C1.

You cannot reverse direction of this handed PAS. Sensor itself creates the pulsed signal and this sensor does not send pulses when pedaling in the "wrong" direction. Controller can't reverse anything since there are no pulses being sent by the sensor when pedaling forward on the right hand side. I tested this by changing my C1 setting from 07 to 02 and what happened was that the motor did not even activate when pedaling backwards any more. When C1 setting was at 07, controller activated the motor when pedaling backwards because it was accepting the pulses. When C1 setting was 02 (or 01, 00) the controller did not activate the motor because it was ignoring the pulses - the pulses were indicating the wrong direction. However the sensor did not send the pulses when pedaling forward so the controller never received the pulses to activate the motor.

I cannot put a disk on the left hand side because I have a Hollowtech BB and I would have to remove a lot of the magnet disk to be able to fit the large diameter of the Hollowtech. Then I would not be able to secure it anyway.

Only solution to use a "left handed" PAS is to flip it 180 degrees. Seems there are other PAS that send signal when pedaling in both directions but this one does not. Anyway, I tested it and it works like this. It is just silly that the supplier indicated this is a "right hand" PAS when it is not.

I bought a conversion kit for ebikes from ebay.
The kit came with a left side sensor. I bought another pas sensor. This one too only works on the left side of the bike(No place due to BB crank,mtb) . After some search work on google i came out on a website in holland that sells pas sensor for the right side of the bike, at least thats what the article says.
https://www.rat-holland.nl/Onderdelen/Overige/P.A.S.-sensor-set-deelbaar. I payed almost 50€ for this so called right side pas sensor. Now i contacted support @ www.rat.holland.nl
To ask them why my right side sensor only works when pedaling backwards.
They just simply told me to flip the sensor upside down (it works in theory)

So basicalle they sell left side pas sensor on their website for 50€ simply by calling them right side sensors.

This is offcourse very misleading. Because i payed like 7$ for a left side pas sensor from ali express. Rat holland sells left side pas sensors and labels them for right side.

Ps: we are now almost 2 weeks later. I guess they just accidentaly send me a pas sensor for the left side. I contacted support again and they did send another sensor ( that looks different) without extra charges, hopefully the right one. I will test it later and update this post. For now im very pleased with their support and service.
Thanks rat.holland.nl

vanoirbeek said:

https://www.rat-holland.nl/Onderdelen/Overige/P.A.S.-sensor-set-deelbaar. I payed almost 50€ for this so called right side pas sensor.

Click to expand...

That is the same one I bought, see my first post. I had the same problem.

What I ended up doing is purchasing this one: https://torquetech.co.uk/collections/sensors/products/electric-bike-12-magnet-easy-fitting-split-pas-pedal-assist-sensor-cadence-speed?variant=10207999623215

Make sure you select "KT-D12R - Right (drive side)". This one definitely works because that is what I am using now. The guy running this webshop also customized it for me by replacing the SM-3A (male) JST connector with SM-3Y (female) JST connector and shortening the cable (so I can route it more efficiently). He charged a small fee for this. I sent him the layout of wires to match my controller input and a photo of the mating connector. I highly recommend Dan and his store, he was helpful, answered my order quickly, and shipped it quickly. He was also seemingly the only one that had this PAS in stock across Europe.

Another thing you can do if you don't want to spend more money is to do what I explained in one of the posts. You can open PAS, remove the potting and flip the PCB. Then put the PCB in some housing that will protect it and still be close enough to the magnet disk. Then pot everything again (I used two part adhesive from Hema, it's excellent).

Better still, don't buy a 12 magnet PAS. They have all sorts of compatibility issues and they offer no perceivable advantage over an 8 or 10 magnet one which are always reversible and compatible.