SW900 PO7 Magnets

[DeanosBeano]

Hi ,
Having recently built my rear hub which uses the SW900 display , i was wondering if anybody knew about the PO7 setting
I have a 36 V 250 Watt 26 inch wheel and want to know the correct setting for this entry because my speed seems off and i cant find any good information on this apart form leave as Default but im not sure its at default because it seems out by about 5 km/h

cheers in advance

PS if you have a 36 volt 250 watt and could scroll through to your setting that maybe a great help too

 

[vfr400]

Hi ,
Having recently built my rear hub which uses the SW900 display , i was wondering if anybody knew about the PO7 setting
I have a 36 V 250 Watt 26 inch wheel and want to know the correct setting for this entry because my speed seems off and i cant find any good information on this apart form leave as Default but im not sure its at default because it seems out by about 5 km/h

cheers in advance

PS if you have a 36 volt 250 watt and could scroll through to your setting that maybe a great help too

P07 should normally be 1. Anything else would give a more than 100% error. Some motors have 6 magnets, in which case you set it to 6 and each 1 you are away from that value would give a minimum 17% error. Magnets often fall off the motor, so if your speedo reading was 5/6 of what it should be, that's what's caused it , and you have to set P07 to 5 or glue the magnet back on.

 

[DeanosBeano]

P07 should normally be 1. Anything else would give a more than 100% error. Some motors have 6 magnets, in which case you set it to 6 and each 1 you are away from that value would give a minimum 17% error. Magnets often fall off the motor, so if your speedo reading was 5/6 of what it should be, that's what's caused it , and you have to set P07 to 5 or glue the magnet back on.

Hey thanks for the information I really appreciate it and it makes sense now , if I look at videos they tell you it's 46 on po 7 so no wonder I'm way out on mine . I'll give 1 a try and let you know how I get on. Cheers .

This ebike thing is hard work to find help I've been to 3 shops so far and I've had the bad looks , I've had er we just plug em in , and I've had mucho dinari before we diagnostic ya bike please .
Internet is the future for ebike people for sure .

 

[vfr400]

Hey thanks for the information I really appreciate it and it makes sense now , if I look at videos they tell you it's 46 on po 7 so no wonder I'm way out on mine . I'll give 1 a try and let you know how I get on. Cheers .

This ebike thing is hard work to find help I've been to 3 shops so far and I've had the bad looks , I've had er we just plug em in , and I've had mucho dinari before we diagnostic ya bike please .
Internet is the future for ebike people for sure .

46 would be for a direct drive motor that doesn't have a separate speed sensor. Geared motors have 1 or 6.

 

[PatM]

Hey thanks for the information I really appreciate it and it makes sense now , if I look at videos they tell you it's 46 on po 7 so no wonder I'm way out on mine . I'll give 1 a try and let you know how I get on. Cheers .

This ebike thing is hard work to find help I've been to 3 shops so far and I've had the bad looks , I've had er we just plug em in , and I've had mucho dinari before we diagnostic ya bike please .
Internet is the future for ebike people for sure .

Ha! This reminds me of Plumbers, years ago. When it was pipes, water and gas-they were happy. When pumps, programmers, 3rd wires and room-stats became the norm- many were buggered. They had learned their craft for years the same old way- then things started to get a bit technical. What its like now is completely modular- the whole thing gets replaced as its not designed to be dismantled on site or anything to tricky. Firms discourage it- they make more margins on 'a new install'. So, buy a bike thats off the net or worse- one where someone had 'made' it from a conversion kit and you better know a bit or be keen to learn from these good pages or similar!
Me- Im an ex lift engineer of 48 years. We experienced the same- electronics simplified controls and wiring- but threw in other challenges.

 

[DeanosBeano]

Cheers @vfr400 setting it to 1 did the trick , just need to find out why it's freezing the odometer and Speedo now after a few hundred yards ,might be after a bump or something.