Kona Ute Electric Conversion - PAS Sensor question

[Dr John C Bullas]

Greetings from Southampton

I am doing a DIY conversion of a Kona Ute cargo bike to make petrol a fuel of the past and lug me, my laptop, a 7 yr old AND a 4 yr. old p the hill to school!

I imported the rear wheel drive kit direct from CNE Bikes without a hitch and other than having to strip down and waterproof the LCD control unit, it is working fine

My question relates to the hall-effect transducer power assist sensor (and 8 magnet rotor): at present the rotor is where it should be and the sensor is being held in register on the frame with an alloy ring as there is no visible thread on the bottom bearing and otherwise the sensor mounting ring would rattle around:

This is the situation "down below"

The yellow tape around bearing is irrelevant: no visible thread to mount the sensor ...

The question is this: can the 8 magnet rotor and 5v pas sensor be replaced with something "correct"... ie. that fits the layout "as is"?

Many thanks in advance for your valued thoughts

n.b. I saw this gizmo (http://www.aliexpress.com/item/2014-new-ebike-kits-PAS-pedal-assist-sensor-hall-sensor/32237661156.html#magnet-ads) but the critical dimension (the depth of splines it takes up) is not given AND it doesn't seem to be available in the UK) [I am happy to stand corrected!]

 

[Kinninvie]

I would just epoxy it in place.

 

[patpatbut]

Search sugru. That what I used to fix the same problem

 

[Dr John C Bullas]

might well have to resort to gluing the sensor down, I just feel that there should be a more professional option since the epoxy will inevitably fail if the sensor gets a clout away from the frame (as it inevitably will)...... there must be many people in a similar position to me,... my work-around keeps the sensor in lateral register with an alloy spacer...

 

[Kinninvie]

You can get that one you linked to but it may take a while,usually around 20 days.

 

[Dr John C Bullas]

Search sugru. That what I used to fix the same problem

can you send me a photo of what you did with it to sort out the mounting? I did think of fabricating the equivalent of the solid spacer that holds the front derailleur away from the frame, to hang on to the sensor.... or a big broom handle

 

[Dr John C Bullas]

once I get the critical dimension I might well order one .... depends on the number or magnets too , I have 8 at the mo 10 might up the speed.....

 

[Deleted member 4366]

You can unscrew the BB a couple of turns, then use a Lockring to hold it on. You can get the lockring from Ebay for 99p or a bit more from your LBS.

The PAS is designed to be fitted on the drive side of the BB where there's a shoulder to hold it. Only fit it on the left side if there's no room there. If you fit it it on the right side, you have to flip the magnet disc otherwise it'll only work backwards.

Isee you have an Octalink type Crank. They're the worst for fitting a PAS. you have to get the hole in the magnet disc just right to be tight enough on the shaft.

 

[Dr John C Bullas]

so basically off with the chainring, the sensor goes under the retaining ring refit retainer, fit centred magnetic disc (check it is working) - then refitting is the reverse of........

 

[Deleted member 4366]

The whole BB has to be removed to fit it, which means you have to remove the chainset.