Do PF30 type PAS sensors exist?

Woosh

Trade Member
May 19, 2012
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wooshbikes.co.uk
Make an L shape carrier with sheet aluminium and put the sensor on the underside of the bottom bracket.
 
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guerney

Esteemed Pedelecer
Sep 7, 2021
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This (8mm wide) sensor would need to be 1/4 or 1/5 of the width it is to work.
Honestly it's easier to just quit trying to make it work and buy a metal bike frame with a standard BB shell where none of this is a problem.
I managed to shave a few millimeters off the plastic box for the sensor.
If you're going to buy another bike frame anyway, you could order another sensor while you're looking for a frame, and remove the box from the sensor you have, to see if you can repackage it smaller? On the other hand, if the sensor's existing box isn't wasting too much space, this could be a waste of time - if so, you'll be waiting for your new sensor while you find your new frame?
 

Manc44

Pedelecer
Jun 21, 2021
140
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Make an L shape carrier with sheet aluminium and put the sensor on the underside of the bottom bracket.
Cheers Woosh, this has got me thinking. o_O

My drawing is atrocious but, it could perhaps be shaped like one of those cassette brushes. Then the straight bit going up the down tube would be attached with cable ties and inner tubing to stop it moving:

44484


Maybe I could actually use one of those brushes, to save having to make anything lol... I'm joking, it needs to bend in and this is flat... but this is what I thought of when I drew the above shape...

44485

Perhaps something like 1mm thick stainless steel along the chainstay might be best, because it can be bent to fit the curve in from the chainstay, with a platform sticking out that goes under the BB shell, bent at 90° then 90° again like the original PAS. Whatever I attach is going to have to have an unattached bit hanging off, that's why I am trying the down tube first.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
20,112
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West Sx RH
I have in the past made a new PAS carrier with a larger offset to move the sensor to create the required gap to the disc, easy to do so if the sensor is placed underneath.
0.6mm - 1mm sheet is all that is needed.
 

Manc44

Pedelecer
Jun 21, 2021
140
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I think I've worked out a way with a straight metal strip along the chainstay, as long as it's bent to match the bend inwards from the chainstay to the BB shell, it will be simple. Then I can just attach that slimmed down sensor box. I'll do pics if it works.
 
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Manc44

Pedelecer
Jun 21, 2021
140
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I can do this the simple way with a strip down the down tube and the sensor screwed onto that, but it means running a chainline that's 5mm too wide. Who knows whether it will run OK or not.

EDIT: I just realised I'm on an old cheap suspension frame at the moment and the rear triangle/swingarm probably has enough play in it that my chainline is around 53mm or 54mm on that bike anyway lol (because I did need it at 51mm to make the current PAS work on it, meant to be 50mm). Swapping to a hardtail where the chainline will be 55mm sounds like it could run rough, but I reckon it should be OK. It's a bit of a deal breaker for me if I can't use PAS.

The problem with me having the chainrings too far out is, now I'm using a motor, I am almost always on the outer chainring, often cross chaining it because I can't be bothered shifting to the middle chainring.
 
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Manc44

Pedelecer
Jun 21, 2021
140
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I'm running it on a wing and a prayer, with just enough spindle spacers so the pedal sensor clears the magnet disc (with some light rubbing) and just less than the amount of spacers that would stop any adjustment being possible on the bearing preload.

Now I am running it on a 54mm chainline, it should be 50mm. It actually runs smoother in the big-big gear than my last setup did on its chainline of 51mm. I put this down to the last frame having play in the swingarm (suspension frame).

This cheap PAS powers the motor if I pedal backwards though, need to be wary of that. :oops: It of course powers it forwards too, lol.

Now I have got the battery pack off the handlebars at last, what a difference it's made to the handling - feels like a normal bike again!