8 magnet PAS vs 12 magnet

Cyclomania

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Hi

So my 12-magnet pas is a bit wide, with a diameter that makes it hard to fit on the crank next to the mid drive motor. But I do have an 8 magnet PAS-sensor with a smaller diameter that fits.

Are there any disadvantages with picking an 8 magnet PAS-sensor over a 12 magnet PAS sensor? I just want to know before I install it.

Thanks
 
Hi

So my 12-magnet pas is a bit wide, with a diameter that makes it hard to fit on the crank next to the mid drive motor. But I do have an 8 magnet PAS-sensor with a smaller diameter that fits.

Are there any disadvantages with picking an 8 magnet PAS-sensor over a 12 magnet PAS sensor? I just want to know before I install it.

Thanks
As long as you change your setting to match (set to 8 magnet). If not, it will take 12/8 or 1 1/2 more crank movement before assist kicks in. E.g. If it takes 1 rotation to kick in now, it will take 1 1/2 rotations if you don’t change the setting.
 
As long as you change your setting to match (set to 8 magnet). If not, it will take 12/8 or 1 1/2 more crank movement before assist kicks in. E.g. If it takes 1 rotation to kick in now, it will take 1 1/2 rotations if you don’t change the setting.
Ah ok.

But the performace will not go down in any way? The PAS of 8 will work just as well as the 12 pas-sensor correct?

As long as I switch the setting?
 
Yup. As always, it’s important to keep the disc magnets aligned with the sensor when mounting the unit.
I have now tested the pas on the bike and it seems to work. Do you think this looks right?

Maybe it starts a little early and stops a little early as well? Seems to kick in very fast and then stop fast when I pedal just a little bit slower.

I guess I could alter this in p11 and p12? These are Pas sensitivity and Pas strength.
I think lower on pas sensitivity makes it start earlier, correct? Or is it the other way around?
 

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I have now tested the pas on the bike and it seems to work. Do you think this looks right?

Maybe it starts a little early and stops a little early as well? Seems to kick in very fast and then stop fast when I pedal just a little bit slower.

I guess I could alter this in p11 and p12? These are Pas sensitivity and Pas strength.
I think lower on pas sensitivity makes it start earlier, correct? Or is it the other way around?
That’s pretty responsive. It shouldn’t impact the assist cutting out when the cranks stop though. If it kicks in too fast you can adjust the magnet count up or adjust p11.
 
An external PAS sensor on a Bafang BBHSD? Am I seeing correctly? Didn't know you could do that. BTW - Stop and start response is adjustable through programming the controller.

passpecial-sauce.jpg
 
An external PAS sensor on a Bafang BBHSD? Am I seeing correctly? Didn't know you could do that. BTW - Stop and start response is adjustable through programming the controller.

passpecial-sauce.jpg
Not sure, but I think he converted to an external KT controller, based on some posts about a month back.
 
Not sure, but I think he converted to an external KT controller, based on some posts about a month back.

Ahh - Makes sense now. Too bad the flexibility of the Bafang controller is lost. Thanks
 
It shouldn’t impact the assist cutting out when the cranks stop though.
You think it looks okay? Or do you think it cuts out too early when the crank stops/slows down?
I had a problem like that with another controller. So it would be best if I could make it work correctly from the start.

Yes this is an external universal controller.
Just looking for a gear sensor as well since I really like those Bafang shift sensors and how they cut power when shifting.

I got a tips from a guy in another thread (this one: Gear sensor for universal controller? ), that perhaps I could hook up one of the brake sensors to a shift sensor. I think he means in parallell, so perhaps the same cable split(?).

Or maybe it could work to use the magnet on one of the brake sensors but on the shift lever at the steer?
An external PAS sensor on a Bafang BBHSD? Am I seeing correctly? Didn't know you could do that. BTW - Stop and start response is adjustable through programming the controller.

passpecial-sauce.jpg
A bbs02 actually :) Yes, you are seeing correctly. A bit of an experiment. I had not learned about the firmware before so I wanted to up the amps on the weak controller I had. So it is used as a gutted shell with holes drilled through the top.

I haven't used it yet so we will see how it works on the road. Yeah the PAS seems to work. Was just a bit of work to get one that fitted in there, between the crank, pedal arms and motor.

I am now looking for a shift sensor solution, since I really like those, for the longevity of the bike parts around the drivetrain.
 
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I prefer a long delay before PAS assistance cuts out, while others prefer it to cutout immediately, so it’s a preference. Most folks want it to kick in fast(er), like yours is doing now though.
I don’t have a BBS##, but a lot of folks say the shift sensor isn’t necessary if you can tap the brake lever and use the cutoff switch to kill power for a second.
 
I don’t have a BBS##, but a lot of folks say the shift sensor isn’t necessary if you can tap the brake lever and use the cutoff switch to kill power for a second.

I think this guy talks about doing exactly that. He says gear sensors are not necessary on torque based pas sensors. I guess I have a cadence based sensor(?) so could come in handy to do some type of cutoff.

That could work. Or..

Maybe I could just put the magnets(or one of them) on the shift lever like I have circled here? Instead of putting the magnets on the brakes.
 

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I am now looking for a shift sensor solution

Personally, I went without the shift sensor and leave my front brake a bit loose and flutter the front brake handle when I need the BBHSD to cut out for shifting. Since I'm a country cruiser I don't shift very often.
 
Maybe I could just put the magnets(or one of them) on the shift lever like I have circled here? Instead of putting the magnets on the brakes.
I can't see the pic clearly, but if you mean the magnetic brake cutoffs that you stick to your hydraulic brake levers, then those should work. You need to place them carefully so they can cut motor power before the disc pads engage, which takes a little trial and error sometimes. I used hot glue on the magnet to find the right placement, and then epoxied the magnet in that spot.
 
I can't see the pic clearly, but if you mean the magnetic brake cutoffs that you stick to your hydraulic brake levers, then those should work. You need to place them carefully so they can cut motor power before the disc pads engage, which takes a little trial and error sometimes. I used hot glue on the magnet to find the right placement, and then epoxied the magnet in that spot.
Yeah that can be a bit tricky. I am thinking I will either go with that solution or the solution he is talking about in the other thread about hooking them up in parallell or something. But that one seems to demand a bit of research. Perhaps I will go with this solution we talked about here to start with.
 
I can't see the pic clearly, but if you mean the magnetic brake cutoffs that you stick to your hydraulic brake levers, then those should work. You need to place them carefully so they can cut motor power before the disc pads engage, which takes a little trial and error sometimes. I used hot glue on the magnet to find the right placement, and then epoxied the magnet in that spot.
Also, do you think my front sprocket looks a bit loose or pretty good in place? I posted about it in this thread: Does this bbs02axle look a bit too loose?

This vid: https://www.veed.io/view/15a1a6f3-5441-43fe-bfc3-0fda2d00bfc2?panel=share

I have ordered a tool looking like this so I can really clamp down on those axle nuts when it arrives. This can be done without too much dissassembling, since the axle nuts are located just below the oil seal in the outer crank.
 

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I used hot glue on the magnet to find the right placement, and then epoxied the magnet in that spot.
What do you think about using tec7? I am not sure if epoxy is basically the same thing as tec7(?).
But I do know tec7 is really strong.

I actually had the problem a few days ago with the magnets falling off again. Pretty annoying.
 
orrrrrrr .... you could choose a different control system. The Cycle Analyst lets you change a whole variety of PAS characteristics. Type of PAS, # of magnets, orientation, delay, power ramp, total power in different PAS levels, different triggers, etc. etc.
 
orrrrrrr .... you could choose a different control system. The Cycle Analyst lets you change a whole variety of PAS characteristics. Type of PAS, # of magnets, orientation, delay, power ramp, total power in different PAS levels, different triggers, etc. etc.
Yeah but a bit expensive and to ship it to Europe I believe is even more expensive.

But I would like to have one of those in the future.
 
Im pretty certain you’d have to put a magnet on both paddles. The motor would need to temporarily cut out on the up shift and downshift.
Yeah. Or just one of them. To mitigate the wear and tear at least a little bit. Not sure if downshifting or upshifting wears the most on your chain and drivetrain? Anyone knows? Which is worse of those two? Up or down.
 
I can't see the pic clearly, but if you mean the magnetic brake cutoffs that you stick to your hydraulic brake levers, then those should work. You need to place them carefully so they can cut motor power before the disc pads engage, which takes a little trial and error sometimes. I used hot glue on the magnet to find the right placement, and then epoxied the magnet in that spot.
In the display there is also one called p7 which is for "speed measuring magnet". Not sure what this is really.

But I do know the bbs02 has 16 magnets inside the motor. But this one is probably something else ?
 
In the display there is also one called p7 which is for "speed measuring magnet". Not sure what this is really.

But I do know the bbs02 has 16 magnets inside the motor. But this one is probably something else ?
Do you have an external speed sensor on your rear or front wheel? You can't measure your bike's speed without an external speed sensor because you're running a mid drive.
 
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