Speed sensor not picking up magnet

[TyJedi]

Hey guys!
I have an original stokemonkey set-up on my Xtracycle conversion since early 2014. I bought it used from a forum member named pdf. It has worked fine for years, in fact the original LifeP04 battery still has about 80% capacity.

Problem know is all of a sudden, my speed sensor does not seem to be getting a signal from the rare earth magnet on the spokes. I thought it was positioning and moved it around, but no matter how close I got it, it didn't pick up any motion when I turned the wheel, EXCEPT one time when the magnet was further away than usual and movement registered on my cycle analyst (which is Version 1.0 for Cycle Analyst and from what Justin has told me before, actually predates the first one he mad for grin.)
)
Here is the magnet:



Here is the sensor:
:

Trying to figure out how to troubleshoot this beyond magnet placement. Should I get a new magnet, new sensor for the fork? Could it be a loose wire, the admittedly ancient cycle analyst, or even the controller?

Any suggestion on what to do next would be welcome.

Thanks in advance,

Ty

 

[amberwolf]

A sensor from that era is probably a glass reed switch inside the plastic tube.

Several things can go wrong:

Most commonly, wires break over time, usually at the points they bend or come out of / go into devices, housings, etc. This breakage is usually just the copper inside the insulation, and may not have any visual indication outside the cable. Touching the cable at the right spot can cause it to work / not work when this is still intermittent.

Solder joints at either the sensor or the CA PCB could fail.

Or water intrusion corrodes them or their connections, anywhere from the PCB inside the CA to the sensor itself inside the plastic.

They are mechanical switches, and they can wear out (though I have never worn one out yet this way).

I don't recall if the ones that old were mounted to PCBs or just slipped into the tube. If they are just friction fit in there, it could have vibrated over a long time to rotate it, or the cable to it could have pulled on it and done this. In this event passing the magnet across it at a different angle will now be needed to trigger it. Imagine a straw with a vertical line on it as the sensor inside the tube. Look down on it from teh top, and set the line so it's at noon, and call that the usual orientation,with the magnet passing from left to right to trigger it. Now you rotate the straw so the line is at 2 oclock, and the magnet is passing at the wrong angle to properly trigger it. Rotating the tube a tiny bit back the other way would fix this.

 

[TyJedi]

A sensor from that era is probably a glass reed switch inside the plastic tube.

Several things can go wrong:

Most commonly, wires break over time, usually at the points they bend or come out of / go into devices, housings, etc. This breakage is usually just the copper inside the insulation, and may not have any visual indication outside the cable. Touching the cable at the right spot can cause it to work / not work when this is still intermittent.

Solder joints at either the sensor or the CA PCB could fail.

Or water intrusion corrodes them or their connections, anywhere from the PCB inside the CA to the sensor itself inside the plastic.

They are mechanical switches, and they can wear out (though I have never worn one out yet this way).

I don't recall if the ones that old were mounted to PCBs or just slipped into the tube. If they are just friction fit in there, it could have vibrated over a long time to rotate it, or the cable to it could have pulled on it and done this. In this event passing the magnet across it at a different angle will now be needed to trigger it. Imagine a straw with a vertical line on it as the sensor inside the tube. Look down on it from teh top, and set the line so it's at noon, and call that the usual orientation, with the magnet passing from left to right to trigger it. Now you rotate the straw so the line is at 2 o'clock, and the magnet is passing at the wrong angle to properly trigger it. Rotating the tube a tiny bit back the other way would fix this.

Thanks Amberwolf! I cut the sensor itself from the fork and passed the magnet over it in as many different directions that I could with my hand. Nothing registers. I'm guessing I need a new speed sensor then? If so, what would you recommend? Warning in advance, my knowledge here is pretty limited, but I am capable of following directions.

 

[amberwolf]

The simplest fix is ordering a new sensor from Grin, it's already in the right package with the right wire, etc.

Usually these are NO (normally open) reed switches. If you don't care what it looks like you can see if your local hardware store has door/window alarm sensors that are this type (many of those are NC, opposite of whaty ou need). Not polarized, so doesn't matter which wire goes to which end.

You can find bare reed siwtches at Mouser, digikey, etc., too.

The same type of sensor is used on many of the typical bicycle computers / speedos, too. If it's a two-wire sensor, it's almost certainly a reed switch just like this.


If you have a spare motor type hall sensor, you can add a wire for 5v from the CA down to the sensor location, and put the hall sensor with it's label side toward the spoke magnet, and wire the sensor up to the former cable. You'll need to verify the pinout for your hall sensor by finding the datasheet for the numbers printed on it (but usually they're the same as the Honeywell SS41 or SS411), and wire 5v, ground, and signal to the appropriate pins. I forget what colors are used in the CA speedo line, but you can verify which is ground by disconnecting the battery from your system, then using a multimeter set to continuity or 200ohms, and measuring from the controller's battery negative input wire to each of the two wires at teh sensor location on the fork. THe lowest resistance wire is ground, and the other is the signal.

 

[TyJedi]

Thanks! I like the simple approach so I will just look into ordering a new sensor from Grin. I was thinking along those lines already, but I like your other suggestions too. Much appreciated!

 

[TyJedi]

The simplest fix is ordering a new sensor from Grin, it's already in the right package with the right wire, etc.

Usually these are NO (normally open) reed switches. If you don't care what it looks like you can see if your local hardware store has door/window alarm sensors that are this type (many of those are NC, opposite of whaty ou need). Not polarized, so doesn't matter which wire goes to which end.

You can find bare reed siwtches at Mouser, digikey, etc., too.

The same type of sensor is used on many of the typical bicycle computers / speedos, too. If it's a two-wire sensor, it's almost certainly a reed switch just like this.


If you have a spare motor type hall sensor, you can add a wire for 5v from the CA down to the sensor location, and put the hall sensor with it's label side toward the spoke magnet, and wire the sensor up to the former cable. You'll need to verify the pinout for your hall sensor by finding the datasheet for the numbers printed on it (but usually they're the same as the Honeywell SS41 or SS411), and wire 5v, ground, and signal to the appropriate pins. I forget what colors are used in the CA speedo line, but you can verify which is ground by disconnecting the battery from your system, then using a multimeter set to continuity or 200ohms, and measuring from the controller's battery negative input wire to each of the two wires at teh sensor location on the fork. THe lowest resistance wire is ground, and the other is the signal.

Hey Amberwolf,

I found this one at GRIN CA_Speedo

And this one on AliBaba

https://www.aliexpress.us/item/3256803908734362.html?pdp_npi=2%40dis%21USD%21%246.62%21%243.31%21%21%21%21%21%402103135816915084986872735e8c8a%2112000028015648210%21btf&_t=pvid%3A431e1de9-1f83-4a96-a6e6-35be1745ca66&afTraceInfo=1005004095049114__pc__pcBridgePPC__xxxxxx__1691508499&spm=a2g0o.ppclist.product.mainProduct&gatewayAdapt=glo2usa

In your opinion, do both of these look ok? What would you suggest? Thanks!

 

[amberwolf]

The Grin one looks different than the last time I ordered that part (mine look more like the originals) but it's the same functionality--two wire connection, NO switch.

BTW, if you add the magnet that comes iwth the new swithc *and* yhour original, and set the CA to 2 poles instead of 1, you get twice the resolution and it can more accurately measure slower speeds, like when nearingg a stop. I use three on my wheel and I can get useful readings as I coast to a stop at intersections.

The AE sensor says
* Speed sensor is an external sensor to detect e-bike speed.
* Connector:SM-3A
* Length:2Meters(approx)
* Color: Black(as pictures show)
* 3pins cables, Red:+5V;Blue:Signal;Yellow:GND
so while itdoesn't say what kind of sensor it is, it requires 5v, so it is probably a hall sensor. you can still use it but you ahve to run 5v from the CA to it to power it.

 

[TyJedi]

The Grin one looks different than the last time I ordered that part (mine look more like the originals) but it's the same functionality--two wire connection, NO switch.

BTW, if you add the magnet that comes iwth the new swithc *and* yhour original, and set the CA to 2 poles instead of 1, you get twice the resolution and it can more accurately measure slower speeds, like when nearingg a stop. I use three on my wheel and I can get useful readings as I coast to a stop at intersections.

The AE sensor says
* Speed sensor is an external sensor to detect e-bike speed.
* Connector:SM-3A
* Length:2Meters(approx)
* Color: Black(as pictures show)
* 3pins cables, Red:+5V;Blue:Signal;Yellow:GND
so while itdoesn't say what kind of sensor it is, it requires 5v, so it is probably a hall sensor. you can still use it but you ahve to run 5v from the CA to it to power it.

Thanks! I only see one cable coming from the CA

 

[TyJedi]

Thanks. Question: In looking at mine, it only appears to be one wire from the speed sensor to the cycle analyst, but it is not a skinny wire either. Keep in mind this was made in 2010 by Grin for Stokemonkey. Very early CA design.
View attachment 337713

 

[amberwolf]

Thanks! I only see one cable coming from the CA

one cable with two wires in it?

or one cable with a single wire in it?

if there's only a single wire, it cannot make any connection and thus cannot have worked before, unless a whole wire in the cable fell out somwhere along the way, in which case you have a second problem.

 

[TyJedi]

one cable with two wires in it?

or one cable with a single wire in it?

if there's only a single wire, it cannot make any connection and thus cannot have worked before, unless a whole wire in the cable fell out somewhere along the way, in which case you have a second problem.

It’s not damaged, and no wire has ever fallen off. I am 100% certain on that. It’s always been one cable from the CA to the sensor as indicated by the red arrow below:
:

BUT I suspect it is probably one cable with two wires based upon what you are saying. I’d have to open up the cycle analyst to see where the wire goes and how it splits to be sure.

Here is a diagram from the original instruction manual showing the speed sensor and magnet:
As you can see, it shows one wire exiting the CA going to the speed sensor.

I was able to find the original manual from 2010 online using Way back machine. Link below if you are want to see the entire manual.

Installation:

Cleverchimp: Stokemonkey: Installation

Getting started and troubleshooting with stokemonkey:

Cleverchimp: Stokemonkey: Getting started

Sorry, I’m obviously NOT an electrical expert! Appreciate your help.

 

[amberwolf]

Youll have to use the actual wire inside that cable that goes to the speed sensor. There are almost certainly two, as that is what all CA's Ive ever used were (regardless of version).

If you're using the grin replacmenet, there are two options. If you can solder you can open up the CA and solder the new sensor's wire to the ca board atthe same points the old one is now.

but if you prefer not to open the ca, you can just install the new sensor in place of the old one on the frame or fork, and run the calbe from it up along the frame where the old cable is now.

then wherever the new cable ends, run the old cable from the ca to that point with at least a little (few inches) slack in the wiring for oopsies, and cut the old cable at that point. strip back the cable housing an inch or two from that cut end, and you see two wires. the new cable probably already has the two wires exposed. it's not polarized so it doesn't matter which wire you connect on the old one to which on the new, as long as they aren't shorting the two wires together.

to actualy connect them it depends on what you have available. the easiest way is with an automotive wire splicer like this

https://www.amazon.com/Connectors-Solderless-Electrical-Insulated-Terminal/dp/B0BN14J6NJ

in the smallest size (you only need two, one for each pair of wires). no need even to strip the insulation from the ends of the wires first. you just put the first wire from the old cable and the first wire from the new one each in one of the slots so it overlaps the metal piece, and close it, and squeeze it with pliers, etc. then with the second splicer, you put the other wire from the old cable and the other wire from the new one just like you did the first time,. and then wrap teh whole thing in your choice of covering depending on the waterproofing you need.

there are plenty of better splicing options that may icnrease the tools or skills you need to use them. one fairly simple one that you can use a lighter or heat gun to complete is these

Amazon.com

these you need to strip a short 1/4" or more of insulation from each of the wire ends, then slip the tube over one of the wires, fed thru far enough to be able to get the stripped end all the way out the other end so you can twist it together with the matching wire from the other cable, then move the tube so the metal bit in the middle is overlapping the bare wire portion, heat it with the lighter or heat gun until the tube shrinks and the metal melts into the wire. repeat for the second wire pair.

there's ohter options if neither of those appeals to you or fits your needs.

the way i would do it is similar to that last, but would need more tools (at least a soldering iron sized for that small wiring, solder, heat gun) than you may have, and you would want to practice on some spare wire first. youll also need at least two sizes of heatshrink, one for the individual wires and one for the outer cable jacket, and the latter needs to be a few inches long to completely cover teh whole splice area and at least an inch or two of the cable jacket to help prevent water ingress.

 

[TyJedi]

Youll have to use the actual wire inside that cable that goes to the speed sensor. There are almost certainly two, as that is what all CA's Ive ever used were (regardless of version).

If you're using the grin replacmenet, there are two options. If you can solder you can open up the CA and solder the new sensor's wire to the ca board atthe same points the old one is now.

but if you prefer not to open the ca, you can just install the new sensor in place of the old one on the frame or fork, and run the calbe from it up along the frame where the old cable is now.

then wherever the new cable ends, run the old cable from the ca to that point with at least a little (few inches) slack in the wiring for oopsies, and cut the old cable at that point. strip back the cable housing an inch or two from that cut end, and you see two wires. the new cable probably already has the two wires exposed. it's not polarized so it doesn't matter which wire you connect on the old one to which on the new, as long as they aren't shorting the two wires together.

to actualy connect them it depends on what you have available. the easiest way is with an automotive wire splicer like this

https://www.amazon.com/Connectors-Solderless-Electrical-Insulated-Terminal/dp/B0BN14J6NJ

in the smallest size (you only need two, one for each pair of wires). no need even to strip the insulation from the ends of the wires first. you just put the first wire from the old cable and the first wire from the new one each in one of the slots so it overlaps the metal piece, and close it, and squeeze it with pliers, etc. then with the second splicer, you put the other wire from the old cable and the other wire from the new one just like you did the first time,. and then wrap teh whole thing in your choice of covering depending on the waterproofing you need.

there are plenty of better splicing options that may icnrease the tools or skills you need to use them. one fairly simple one that you can use a lighter or heat gun to complete is these

Amazon.com

these you need to strip a short 1/4" or more of insulation from each of the wire ends, then slip the tube over one of the wires, fed thru far enough to be able to get the stripped end all the way out the other end so you can twist it together with the matching wire from the other cable, then move the tube so the metal bit in the middle is overlapping the bare wire portion, heat it with the lighter or heat gun until the tube shrinks and the metal melts into the wire. repeat for the second wire pair.

there's ohter options if neither of those appeals to you or fits your needs.

the way i would do it is similar to that last, but would need more tools (at least a soldering iron sized for that small wiring, solder, heat gun) than you may have, and you would want to practice on some spare wire first. youll also need at least two sizes of heatshrink, one for the individual wires and one for the outer cable jacket, and the latter needs to be a few inches long to completely cover teh whole splice area and at least an inch or two of the cable jacket to help prevent water ingress.

I like both of those methods, thanks. And I’m fine with soldering. My first job 42 years ago was to assemble electronic models for machines that serviced catapult tractors. I only did it for less than a year, but I do remember some of the basics.

I ordered the new sensor from GRIN. To me, it seems better to follow their directions and try to attached the new cable straight to the 2010-era Cycle Analyst, but it depends on what I see when I open it up. The directions for the new speed sensor seem pretty straight forward, but they used a modern Cycle Analyst version 3 and mine predates the first one offered at GRIN. But hoping It will be obvious where things go when I open it up.

But if not, I'll cut the wire down near the sensor per your suggestions and attach the new one. I ordered the simple connectors you mentioned just in case I go that route. I have some shrink tubing on hand from when I had to replace some of the old Anderson connectors that weren't connecting right when I first bought the stokemonkey and had it mounted to my Xtracycle conversion. They might not be the right size, but luckily I have a great old-school electronics store only a few miles away and then have every size imaginable.

Thanks again for your advice. Looking forward to getting my rig back on the road.

Thanks again,

Ty

 

[amberwolf]

I recommend making the actual connection up near the CA itself, if you can't do it isnide it. the closer it is to the wheel, the greater possibliyt of water intrustion, etc. into the splice.

 

[TyJedi]

That was my thought too, thanks. I'm hoping I can get the new one entirely inside the CA. I don't get the new speed sensor until next week, but I'm going to open up the CA today to see what I'm dealing with.

 

[TyJedi]

Well I opened up the Cycle Analyst, which by the way is 4" x 2," so pretty small, The red arrows are pointing to the speed sensor cable itself. The cable is split off into one for speed and one for ground, so definitely two wires with an outer wrap. you can see where they go right near that mustard-colored piece of plastic, just below where the controller wires come down:


It is definitely two wires covered by a rubber coating of some kind as you can see where I have the red arrow pointing:


I can definitely see it is going to a spot marked S for speed and G for ground. They are the same color, so I assume that means it doesn't matter which goes where:



It's awfully small and tight in there which makes me a little nervous about soldering it in there. I know WHAT to do, that's not the issue. It's just that there is not a lot of real estate in there.

But maybe I could connect the new Speed sensor cable inside the Cycle Analyst, but not at the board, meaning somewhere along at the point it comes in from outside and then onto the board, like where I indicated here:


I did order the easy connectors from Amazon, but they have not arrived yet. Not sure if connected wires will still fit inside of the CA. What do you think?

If not, I could connect the new wire to the old just outside the Cycle Analyst box and do a good job with the shrink tubing, it could be ok...

Thanks again for your continued help and advice.

Ty

 

[amberwolf]

You might not be able to fit the easy-connector type stuff inside the CA; I have a very old one with that size board and box, and there's really not much room in there; I don't think I can get my forefinger between the board and case (maybe my pinky tip). If it does fit, that's good, as it keeps the entire interconnect out of the weather.

If you go the HS/solder route, you can do that inside the CA for sure. You can pull as much of the old wire into the casing as you need, when you're putting the new cable in thru the old hole.

Before you connect the new cable up, tie a loose knot in it where you want it to stop being able to come back out of the case. Or put a ziptie on it at that point, same idea.

 

[TyJedi]

That makes sense, thanks for the tip. I'll make sure to tie a knot.

I looked at the Haisstronica connectors and I'm sold! They look to be a perfect solution and also appeal pretty intuitive to use. I particularly like how they are weatherproof as I am not averse to riding in the rain. Just ordered a set. Thanks for the recommendation.

By the way, hope things are going well with you. I actually read your entire thread about the house fire, dog illnesses, etc years ago when I first got the stoklemonkey for my Xtracycle. My wife even read it too after I told her about it. It was compelling and vivid and I really felt like I was there. I think I encouraged you then to turn your experiences into a book. I still think you could touch a lot of people with your story.

 

[amberwolf]

I looked at the Haisstronica connectors and I'm sold! They look to be a perfect solution and also appeal pretty intuitive to use. I particularly like how they are weatherproof as I am not averse to riding in the rain. Just ordered a set. Thanks for the recommendation.

Sure. There are lots of brands, those were just some random ones that came up in amazon's search. I don't recall which brand I bought a couple years or more ago, not long before Kirin and then Yogi died and I lost the ability to deal with anything at all for about 3/4 of a year, and was put on medical leave for half a year, unable to work (so no paycheck). (it was worse than the fire, which I did not think possible, and while things are a lot better, I am still not really over either event, or the intervening ones, not sure I ever will be).

I don't know that any particular one is better than another on amazon, but there probably are some really good ones out there somewhere on the web with marine grade heatshrink that's adhesive lined (which really could be waterproof if they shrink correclty to the wire insulation).


EDIT: I looked it up and this was the one I got; they work alright, I'm sure there's better ones.

https://www.amazon.com/gp/product/B07R4Z13P3

By the way, hope things are going well with you. I actually read your entire thread about the house fire, dog illnesses, etc years ago when I first got the stoklemonkey for my Xtracycle. My wife even read it too after I told her about it. It was compelling and vivid and I really felt like I was there. I think I encouraged you then to turn your experiences into a book. I still think you could touch a lot of people with your story.

Thank you, but...I am not sure how to write a book...I could copy and paste everything there into a single document, but I am not sure how to edit that into a book, or who would publish it, or how. I don't even really know how to tell a story.

(I've tried over the years, in text, and in my mostly-instrumental music, and it doesn't work...at least, I assume it isn't working because very very few read or listen, and nearly zero of those that did would talk with me about it, or pass it on to others they know...I don't even think I still have copies of any of the text stories, but some of the music is still out there on the internet).

 

[TyJedi]

Sure. There are lots of brands, those were just some random ones that came up in amazon's search. I don't recall which brand I bought a couple years or more ago, not long before Kirin and then Yogi died and I lost the ability to deal with anything at all for about 3/4 of a year, and was put on medical leave for half a year, unable to work (so no paycheck). (it was worse than the fire, which I did not think possible, and while things are a lot better, I am still not really over either event, or the intervening ones, not sure I ever will be).

I don't know that any particular one is better than another on amazon, but there probably are some really good ones out there somewhere on the web with marine grade heatshrink that's adhesive lined (which really could be waterproof if they shrink correclty to the wire insulation).


EDIT: I looked it up and this was the one I got; they work alright, I'm sure there's better ones.

https://www.amazon.com/gp/product/B07R4Z13P3

 

[TyJedi]

not long before Kirin and then Yogi died and I lost the ability to deal with anything at all for about 3/4 of a year, and was put on medical leave for half a year, unable to work (so no paycheck). (it was worse than the fire, which I did not think possible, and while things are a lot better, I am still not really over either event, or the intervening ones, not sure I ever will be).

That's tough... I've gone through a couple of year-long disabilities, one due to an injury to my hand due to being "doored" and the other due to back. Both lasted nearly a year.

We also lost our beloved Yorkie Guinness3/2022. He was nearly 16 and he just wore out. It still feels fresh and don't know if we will ever get over it. He was a very special dog and visited children getting chemo, dialysis, etc, at Stanford Children's hospital for over 10 years.
(He is the one closest to my bike. Penny (age 10) is closest to the camera. She is still with us.)

hank you, but...I am not sure how to write a book...I could copy and paste everything there into a single document, but I am not sure how to edit that into a book, or who would publish it, or how. I don't even really know how to tell a story.

(I've tried over the years, in text, and in my mostly-instrumental music, and it doesn't work...at least, I assume it isn't working because very very few read or listen, and nearly zero of those that did would talk with me about it, or pass it on to others they know...I don't even think I still have copies of any of the text stories, but some of the music is still out there on the internet).

For someone who thinks they don't know how to tell a story, you told one well. I don't know, maybe look for a writers group on Facebook? Somebody might be able to steer you in the right direction.

 

[TyJedi]

Hey Michael!

I wanted to thank you again. I used the solder-seal wire and it worked really well. Long story short, the new sensor is working just fine. I was a little nervous when I cut the cable of the old sensor because at first I thought it was only one wire, but it was actually two sets of very very fine wires inside the casing. One was essentially loose and other set of fine strands was wrapped in fine black tubing of some kind. I tested it by twisting it onto the CA, spun the wheel and voila! I had MPH showing up. I used one of the smallest solder-seal tubes, lined everything up and used the heat gun.

My only mistake was I bought a set of heat shrink tubes that were all pre-cut and I only put one piece on ahead of time. Not enoght to cover the wires I had exposed. I did some ugly improvisation by putting a couple of the smallest pieces that would fit over the speed sensor and shrunk them down as much as I could and squashed them in my fingers while wearing some leather work gloves. Finished it off with old fashioned electrical tape. It's ugly as hell, but functional. I might redo it at some point, but probably not as nobody but me would really notice it.

Bottom line, when I hit the throttle, it works! MUCH thanks again for your guidance and help. I did send you a little something through your PayPal as a thank you.

Ty

 

[amberwolf]

I'm glad it works, and thanks.

If I can ever keep my mind on it long enough, maybe I can go thru that thread and consolidate it into something readable by "everyone".

No idea who would publish such a thing, though.

 

[TyJedi]

I think a lot of dog lovers would really love it. Your "blog" reminded me of books like "Marley and Me" and "The Art of Racing in The Rain." Both have heartwarming stories of the love people have for their dogs as well as the depth and profound sadness when they pass. What happened with you and your dog, the fire, loss... it had a similar vibe.

My wife, who is NOT into bikes and NOT a big reader, read all of your posts too.

As far as a publisher, I have a few professional authors as friends I could ask about where and how to publish. Just let me know and I'll look into it for you.