Speed Sensor Fitting

[snappyfish]

Hi,

Recently got a Yose rear wheel kit.



The pedal sensor above provided won't fit as no room between the crank arm and the bb cup. Talking like 2-3mm. The BB is square taper 73x113

I have seen swytch bike do one that zip ties to the crank arm is this available or similar?

 

[saneagle]

That's the pedal sensor. Speed sensor is in the motor or on the frame next to the wheel. You can use any pedal sensor you want. Whatever connector it has cut them off and solder the wires directly to save messing about.

Another trick I've used many times is to grind 3mm off the inner side of the pedal arm to make room for the sensor. That saves a bit of weight too.

 

[snappyfish]

That's the pedal sensor. Speed sensor is in the motor or on the frame next to the wheel. You can use any pedal sensor you want. Whatever connector it has cut them off and solder the wires directly to save messing about.

Another trick I've used many times is to grind 3mm off the inner side of the pedal arm to make room for the sensor. That saves a bit of weight too.

Sorry, I meant the pedal sensor.
It's Incredibly tight.. will try and have a go at a different pedal sensor then...

The Swytch kit one does look ideal though but can't see it for sale anywhere.

Might email them.

 

[snappyfish]

ok, I am using this type of disc, I have an enlarged hole to fit over the indent on the crank arm...

whats the best glue/bonding agent to fix the disc to the crank arm?

 

[saneagle]

Before gluing anything, test by turning the disk by hand against the sensor to see which way up the magnet disk has to go. You can't go by the markings on it.

Why don't you grind/file off 3 mm from the inside of the pedal arm rather than glue the disk?

 

[Woosh]

Installing a large disc on the non drive side is a bad idea. It is going to be regularly hit by your left shoe and loses its grip on the axle in a few months. A better solution is to replace your bottom bracket with one with 5mm longer axle. For your bottom bracket, 73 x 117.

 

[snappyfish]

Before gluing anything, test by turning the disk by hand against the sensor to see which way up the magnet disk has to go. You can't go by the markings on it.

Why don't you grind/file off 3 mm from the inside of the pedal arm rather than glue the disk?

Not really a fan of fileing pedal arms. But may try it.

 

[snappyfish]

Installing a large disc on the non drive side is a bad idea. It is going to be regularly hit by your left shoe and loses its grip on the axle in a few months. A better solution is to replace your bottom bracket with one with 5mm longer axle. For your bottom bracket, 73 x 117.

But the gears will be out? it's a triple chainset currently.

 

[Woosh]

But the gears will be out? it's a triple chainset currently.

The chainrings will move outward 2mm, it's easy to adjust.
There are plenty of Youtube videos how to adjust the front derailleur.

 

[guerney]

Another trick I've used many times is to grind 3mm off the inner side of the pedal arm to make room for the sensor. That saves a bit of weight too.

Installing a large disc on the non drive side is a bad idea. It is going to be regularly hit by your left shoe and loses its grip on the axle in a few months

But the gears will be out? it's a triple chainset currently.

Might be worth a go: I've used superglue and very fine grain "Food grade" bicarbonate of soda to stick metal to plastic several times over the past few months - the combination is an incredibly strong adhesive. I haven't yet needed to try the even stronger superglue + graphite.

After discovering the tiny screwheads of these tiny screws easily broke off when tightened, and had fouled the very short thread of the thin aluminium casing, I bonded the plastic light mount to the aluminium casing of this Planet X bike light. This plastic-like material can be sanded down and shaped.




After epoxy resin failed to bond a block of wood to metal strongly enough, and superglue by itself didn't work, I lightly dusted over the wood with fine grain food grade bicarbonate of soda, squirted over cheap and very runny superglue, then quickly pressed the wood to metal. It set within about 10 seconds. Then I screwed in hooks to hang heavy items from.

Some superglue types are less runny than others, some set slower. Bicarbonate of soda reduces setting time considerably, and runny fast-setting superglue is difficult to control... therefore I suggest that the OP consider using epoxy or superglue to stick the disc to the pedal arm, after it's been ground to size as @saneagle suggested, then apply superglue + bicarbonate of soda in layers all the way around, or superglue + graphite. Then file and sand it down. The material can be coloured black using a permament marker. But I'd test to see if superglue dissolves the disc's plastic first. This light hangs down, it's stuck like stink.

p.s. Have acetone handy, to dissolve superglue on your fingers!

p.p.s. The superglue combinations mentioned could be too brittle for this application.

 

[saneagle]

Installing a large disc on the non drive side is a bad idea. It is going to be regularly hit by your left shoe and loses its grip on the axle in a few months. A better solution is to replace your bottom bracket with one with 5mm longer axle. For your bottom bracket, 73 x 117.

Mine's sat there for 9 years now and is still working perfectly. It's done about 4000 miles in that time. I can't see how you'd kick it. Your foot doesn't go anywhere near it.

 

[Woosh]

You are good with things like that but I know when a part or a solution is statistically troublesome for support.

 

[snappyfish]

Thanks for the help. Got it sorted now.