Alternatives to flipping PAS disc?

[Yak]

Morning all. I recently had the bottom bracket replaced, but the shop just handed me the PAS disc with a shrug and told me i doesn’t fit any more, as they had fitted a modern replacement. There’s a long story there but what I’ve done is carefully shape the disc to fit to the drive side and glue it on. Backwards, it turns out, as the motor now only comes on pedalling backwards. Flipping the disc isn’t really an option - a thread here suggests I can rotate the sensor but I can’t figure out which way...

 

[vfr400]

Remove the sensor from its bracket. Drill the holes in a mirror of how they were and refit the sensor 180deg rotated so that the magnets pass in the opposite direction.

Whenever fitting a pedal sensor, always test it before putting the crank back on. It'll save a lot of work.

 

[Yak]

Thanks (again) vfr - so I’m drilling holes to mount it back onto the bracket and rotate it like this? There’s also a red led, can I just ignore it?

 

[vfr400]

You have to turn it 180 deg lengthwise, so that the cable is at the other end.

 

[Yak]

I’m looking...but inverting the sensor means I can’t position it close enough to ‘reach’ the magnets, and the sensor bracket is already as close to them as the frame allows. There is no problem taking the cranks off - it’s just that the magnet disc has been glued to the chainring so it can’t be flipped! You can see where I have put it in the pics with the sensor below. I’m beginning to think I may have to prise it off though...
I don’t suppose there is some magical setting on the Lishui screen that allows for changing sides?

 

[Scorpio]

I don't think you have space to rotate the sensor 180*, some older sensors are on a flat metal bracket and can be flipped by just undoing the locating screw.
Which controller do you have? I think the sensor on some can be programmed to work in reverse which would fix your problem.

 

[Yak]

It’s the same Lishui as you had Scorpio, that came with the Yose kit. You flipped the magnet disc when you fitted it to the drive side I assume? Like a wise person would?

 

[Yak]

I am a moron. Let’s hope it works.

 

[Yak]

Darn. It didn’t. I saved the setting to ‘back direction’, but whereas before the LED lit up and the motor came on (forwards) when pedalling backwards, now the light still only comes on when pedalling backwards, but there is no power in either direction. I feel I’m close...It’s really frustrating!

 

[Nealh]

One should have checked the disc orientation before gluing it on, can you not warm up the glue to remove the disc to flip it or try pressing out the magnets and rotate their orientation.

 

[Yak]

One should have checked the disc orientation before gluing it on, can you not warm up the glue to remove the disc to flip it or try pressing out the magnets and rotate their orientation.

Oh I know that now. Hindsight is 20/20! Hmmm, I’ll try and see it the magnets will come out. Thanks for the idea. I can always glue them back in (I’m good with glue!)
I wonder why changing the setting didn’t work?

 

[Nealh]

The best option will be to try and unglue the disc and flip it or bash it off clean up the chain ring surface and fit a new disc (having check orientation).

 

[vfr400]

Get a new sensor.

 

[Yak]

A bit of heat helped get the disc off the chainring unharmed, so a bit more whittling so it fits the proper way around and I’m good. Thanks for all the suggestions guys. I really appreciate this site. Is there a rapid (ie not Chinese) source of magnet discs so I have a spare?

 

[vfr400]

A bit of heat helped get the disc off the chainring unharmed, so a bit more whittling so it fits the proper way around and I’m good. Thanks for all the suggestions guys. I really appreciate this site. Is there a rapid (ie not Chinese) source of magnet discs so I have a spare?

Ebay

 

[Scorpio]

It’s the same Lishui as you had Scorpio, that came with the Yose kit. You flipped the magnet disc when you fitted it to the drive side I assume? Like a wise person would?

Thanks for assuming I'm a wise person, wrong in this case as I tried reversing the disc and it made no difference so I removed the (old style) PAS sensor from it's bracket, flipped the sensor 180*, then spliced the old sensor wires to the "waterproof KT" harness. It's not the sensible or easy option but it works

 

[Yak]

I do make myself laugh sometimes. I bit the bullet yesterday and reversed the disc. Really made a nice job of it too. Waited 16hrs for the glue to dry and voila! As Scorpio points out above, it still only works pedalling backwards. So, with no room to invert the sensor I guess I need to try what he did. Bit nervous - I’m a builder and happier with a cement mixer than a soldering iron. Do you have photos?

 

[Scorpio]

See photos half way down the page https://www.pedelecs.co.uk/forum/threads/yose-350-rear-hub-kit-transplanted-onto-scott.40186/
I used a non-yose sensor as that's what I had available, I have a yose sensor on another bike but don't see any way I could reverse it if I needed to.

 

[Yak]

I looked at those photos before but couldn’t see the sensor! I understand now that there are sensors on rings, which I can see could be flipped - or completely butchered !-) - whereas our type can’t. The comments from the guys above now make sense too. I’ll get one sent out and see what I can do. I still don’t get why changing the direction setting on the display didn’t work though. That would have been nice.

 

[vfr400]

I looked at those photos before but couldn’t see the sensor! I understand now that there are sensors on rings, which I can see could be flipped - or completely butchered !-) - whereas our type can’t. The comments from the guys above now make sense too. I’ll get one sent out and see what I can do. I still don’t get why changing the direction setting on the display didn’t work though. That would have been nice.

It only works on the cheapo single hall type. Those type of sensors work simply and reliably. I can't understand what the advantage in dual sensors is. They only bring compatibility problems