January 28, 20197 yr I’m looking to change my pas from 8 to 12 magnet one. Can I simply change the disc with the magnets or do I need to replace the sensor part too? The existing one has a waterproof connector which are quite a bit more expensive than the ones with a normal connector. So I was just going to buy a cheaper 12 magnet one and just use the disc. Would my existing sensor be compatible with a 12 magnet disc?
January 28, 20197 yr Author I did it on a Viking e-bike and went from 6 to 12 and it works fine....... Thank you. So, just changing the disc is fine? No need to change the sensor part?
January 28, 20197 yr Thank you. So, just changing the disc is fine? No need to change the sensor part? No the sensor is the same in most cases. You might have to set 12 magnets in the configuration menu, I didn't bother and it worked, now it is set to 12 though.
January 28, 20197 yr Author No the sensor is the same in most cases. You might have to set 12 magnets in the configuration menu, I didn't bother and it worked, now it is set to 12 though. Thanks for your reply. Sounds good. Does it make the motor any smoother?
January 28, 20197 yr Does it make the motor any smoother? Tends to make the PAS respond quicker with less crank rotation needed before it starts the motor.
January 28, 20197 yr Smooth running tends to be more down to the way the programming runs in the controller, which you can't do anything about on alot of bikes.
January 28, 20197 yr Author Smooth running tends to be more down to the way the programming runs in the controller, which you can't do anything about on alot of bikes. I understand. Quicker responding pas is what I’m after. Thanks.
January 28, 20197 yr Quicker take up and smoother running for me, just be sure you order the right sized magnet disc.
January 28, 20197 yr Don't waste your time and money. I bet you won't notice any difference, except that it might not work at all because some controllers don't like them. Why do you want to change it? Is it because your controller gives a delay? That won't change by using a different magnet disc.
January 28, 20197 yr Is it just me, or does anyone else get a sense of D8veh?, bless him:D Funny you should say that, I have been thinking the same thing for a few weeks now. Possibly vfr was another alias ? .
January 29, 20197 yr https://www.pedelecs.co.uk/forum/members/vfr400.5808/#recent-content Cat's out fo the bag!
January 29, 20197 yr If I remember D8veh more then once referred to motor bike ownership and may have once mentioned the vfr so yes I think he has returned using the old alias. No matter which name he posts under, welcome back .
January 29, 20197 yr Author Don't waste your time and money. I bet you won't notice any difference, except that it might not work at all because some controllers don't like them. Why do you want to change it? Is it because your controller gives a delay? That won't change by using a different magnet disc. Yeah. It’s because of the delay. Thought it would be worth a punt, only €4. Thanks for the advice. No point if you think it won’t make any difference.
January 29, 20197 yr More poles will as mentioned reduce rotation delay though depending on the controller settings may need tweaking if an lcd allows such as with KT's. I replaced 12 pole disc one with a 10 pole one and didn't change the parameter for it and had a stuttering on/off delay with PAS/ hub sensing from the controller , after changing the parameter everything behaved as expected and no more issues.
January 29, 20197 yr Author More poles will as mentioned reduce rotation delay though depending on the controller settings may need tweaking if an lcd allows such as with KT's. I replaced 12 pole disc one with a 10 pole one and didn't change the parameter for it and had a stuttering on/off delay with PAS/ hub sensing from the controller , after changing the parameter everything behaved as expected and no more issues. I’m using a kt-lcd3. Can you advise me on what parameters to change and to what value when changing from 8 to 12 magnets.
January 29, 20197 yr C1 is the setting and value should be 2 for 12 pole disc, the 8 pole disc should be currently set at 0. Also you can adjust C14 for PAS signal strength 1 - 3 /weak to strong. If you find that pas for some reason is a bit on/off and intermittent then try values 0 or 1 or check the sensor to disc gap is about 1mm and magnets are actually passing the sensor correctly. Edited January 29, 20197 yr by Nealh
January 29, 20197 yr Author C1 is the setting and value 3 for 12 pole disc, the 8 pole disc should be currently set at 00. Thanks very much.
January 30, 20197 yr A bit of basic geometry will tell you that 12 magnets is going to give quicker start up than 8. One third quicker to be exact. It greatly improved my riding experience. A 10 magnet disk would also be a 20% improvement. Once you are actually turning the pedals at normal cadence there is no difference to be felt (of you have the correct number of magnets set).
January 31, 20197 yr The two Raleigh Arrays in my family have a PAS sensor that directly senses the teeth on the front chainring. So about 42 "magnets". These bikes are a real pleasure to ride; presumably the PAS arrangement helps with the fast and smooth pickup. I'd really like to find a source for those chainring PAS sensors, but so far I've drawn a blank
January 31, 20197 yr The two Raleigh Arrays in my family have a PAS sensor that directly senses the teeth on the front chainring. So about 42 "magnets". These bikes are a real pleasure to ride; presumably the PAS arrangement helps with the fast and smooth pickup. I'd really like to find a source for those chainring PAS sensors, but so far I've drawn a blank What about using something like this to detect the chainring teeth: https://www.ebay.co.uk/itm/M18-8mm-DC-5V-NPN-NO-LJ18A3-8-Z-BX-5V-Inductive-Proximity-Sensor-Switch/113223650675?hash=item1a5ca7cd73:g:pFkAAOSwPPNbhRS3:rk:3:pf:0 It works on a 5V input and detects aluminium and iron from a distance of 4mm.
January 31, 20197 yr What about using something like this to detect the chainring teeth: Interesting, thanks. Unfortunately a PAS sensor needs to be a "dual" device so that it can sense whether the chainring is going forwards or backwards.
February 1, 20197 yr a PAS sensor needs to be a "dual" device so that it can sense whether the chainring is going forwards or backwards. Never really thought too much about this, but now does the controller know which way the crank is turning? Where does the "duel" bit come from with a 3 wire sensor, positive, neg. and signal? Isn't it just a 3 pin hall sensor?
February 1, 20197 yr Never really thought too much about this, but now does the controller know which way the crank is turning? Where does the "duel" bit come from with a 3 wire sensor, positive, neg. and signal? Isn't it just a 3 pin hall sensor? The controller doesn't know, but the sensor does. Inside a 3-wire dual hall PAS sensor is a pair of hall sensors spaced much closer together than the magnet spacing and some basic logic processing circuitry. This is used to calculate the direction of movement and limit the output to a single direction of rotation. Edited February 1, 20197 yr by danielrlee
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