PAS fixed to gates rear sprocket?

LithiumFan

Pedelecer
Jan 6, 2019
36
6
Herefordshire
I am thinking of getting a bike with a pinion gearbox but want to fit a rear hub motor so I need to fit a PAS. I have bad knees so really don't want a torque sensor. I have been very happy with Xiongda 2 speed motor which I have had on a total of three bikes, doing the conversions myself, and have done over 7,000 miles, a lot offroad as well as tarmac. I really want to use the same type of motor. With the pinion gearbox it doesn't look as though I can use a PAS sensor at the crank because the gearbox is flat. If anyone has succeeded in this please post with what they did.
Looking at pictures of rear axles with a Gates belt sprocket it does look easier to fix a PAS there. It would just need a longer cable which I can sort out. Is this possible?
I have seen a Geeko hub motor with a cassette based PAS sensor but I have feeling it would not work on a different motor... Also I love the 2 speed system on the Xionda as I can get up almost anything.
Please, no comments about why I should use a mid drive. I have one but much prefer just having a fixed power level I can control with my thumb which I use actively to get a great range. Last Sunday I managed 36 miles on a 36v 6Ah battery on the Traws Eryri route from Betws-y-Coed to Conwy. I am not interested in speed. I often go up hills at just 5 or 6mph in low power in a low gear. Pushing or using the walk button where necessary.
Cheers.
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,823
3,154
Telford
If I were doing it, I'd glue magnets to the back of the chainwheel and either glue the sensor in place or make a custom bracket for it that holds it in the right place. The magnets have to go the right way up and the sensor in the correct orientation too, so test it first to see which way round things go. You can push the magnets out of a normal magnet disc or buy them from Ebay for not a lot.
 

thelarkbox

Esteemed Pedelecer
Aug 23, 2023
1,211
371
oxon
Ive read posts where folk have put the pas sensor on the front wheel and other places so sure you can. just get the rotation direction right but if tricky you can get a right hand side or left hand side version as needed.

First time my bike hit 15mph not going downhill was post conversion ;)
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,823
3,154
Telford
Ive read posts where folk have put the pas sensor on the front wheel
An engineer told me before he died......................
Now we come to the tragic bit...
There was no way of stopping it...
It went like the piston of a train,
He should have fitted a gearing chain,
Clouds of steam blew out the top,
There wasn't a way to make it stop,
 
  • :D
Reactions: thelarkbox

Voltsnamps

Pedelecer
Aug 27, 2023
70
13
An engineer told me before he died......................
Now we come to the tragic bit...
There was no way of stopping it...
It went like the piston of a train,
He should have fitted a gearing chain,
Clouds of steam blew out the top,
There wasn't a way to make it stop,

:)Enough, enough, the maiden cried !

Had me giggling, at least
Got me thinking, how about a fck off big front hub motor on a fixie with torque sensor on BB, no speed limit nor brake sensors .

Someone might like to give one to Bibi at the top of Mt Sinai (to celebrate the successful modern interpretation of just the first of those lovely 10 Commandments). A little push to get him started might be enough.
 

thelarkbox

Esteemed Pedelecer
Aug 23, 2023
1,211
371
oxon
An engineer told me before he died......................
Now we come to the tragic bit...
There was no way of stopping it...
It went like the piston of a train,
He should have fitted a gearing chain,
Clouds of steam blew out the top,
There wasn't a way to make it stop,
Brake cut off sensors would need fitting But if omitted like some builds yeah could be an issue ;)