Rain killed my pedal sensor :(

Rain killed my pedal sensor (for 3 days)

 

My Urban Mover UM36 is now a throttle-only assist bike, yesterday's downpour killed the pedal sensor

The battery was inside being charged and the bike locked up outside, I'd left the bike out in worse rain before with no problems but with the battery still on, I think the rain must've got through where the contacts are.

 

And I still haven't managed to get my 12Ah battery back, mainly because I don't own a car so going to collect it means arranging a time I can borrow a car at a time when someone from Urban Mover will be able to help me out, now my bike problem has got worse and it doesn't help when they say they'll call back and they don't.

 

Damnit, I really like riding an electric bike but I think this one's jinxed

Edited July 30, 200718 yr by Haku

Not just UM though Haku, many e-bikes hate rain.

 

Bikes are very vulnerable, much more than motorcycles where there's plenty of protection from tank, radiator, cowlings, engine etc to hide electrics behind.

 

Should be ok after a thorough dry out, but it would be a good idea to proof all the vulnerable points when you have a chance, and certainly before the winter.

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I was hoping that giving it time to dry out would sort it out but it hasn't, after it rained heavily on it I dried out the contacts before putting the battery on, then when I first started pedalling it didn't provide any assistance, then it kicked in and wouldn't stop going after I stopped pedalling, after switching the battery off then on again it stopped working completely leading me to think that the circuitry to do with the pedal sensing is toast.

 

What really annoys me about the situation is that as I've mentioned before, the throttle spring is too strong and using it for anything more than a few minutes makes my wrist ache, plus the throttle only gives you 10mph max when the pedal sensor gave you 15mph.

 

Looks like next week for me is "Pester UM 'Til They Fix It Week" because I can see it taking that long to get some action from them

Since I first started using the Sram Sparc system on a Dahon Roo El over a year ago I have now and again looked at other systems to see if they might be better, but doubts about external pedal sensors have always put me off other offerings, as they are vulnerable to water ingress and dirt (in some cases they appear to be designed in the same way as a speedometer with a tiny magnet on the spokes passing a sensor on the forks).

 

The sensor on the Sram system is inside the hub somewhere in the electronics, as are the gears in the hub gear, and the two motors. It is possible to get dirt inside that hub round the sides of the hub cover (opposite side from the drive side) but you need to go through very deep muddy puddles to do that.

No need to fear the external type of pedal sensor you describe Rooel, the pickup is normally sealed at manufacture and doesn't give any water trouble.

 

For example the eZee bike pedelec sensors are constantly sprayed with water from the front wheel all the time when riding in rain or through standing water and it makes no difference to their operation.

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Didn't use my bike on Saturday but went to a friends earlier today (Sunday) on my bike and discovered the pedal sensor is working again!

 

2-3 days to dry out is a fairly long time, I wonder what actually got wet? I don't know how the VPAC (variable pedal assist control) does it's thing, I've seen mention of magnets with hall effect transducers and optical sensors (fibre optic?) for pedal assist but don't know which the VPAC uses.

Just phoned up to ask about getting my original 12Ah li-pol battery back (still on the 8Ah li-ion) and said about the pedal sensor stopping working, solution I was given for the future was to use a hairdryer pointed at the pedal sensor to dry out the water blocking four infra-red LEDs. Still yet more delay on getting my battery back though.

As discussed in other posts, like Haku I have an Urban Mover bike, but I don't have the pedal torque sensor, just the movement sensor that switches the motor full-on when the pedals turn.

 

I rode my bike to work on 20th July, the day of monsoon-conditions in southern England. It was parked in the rain all day. I always cover the saddle with a plastic bag big enough to pull down over the top half of the battery, to protect the connections. In heavy rain, I put another plastic bag over the handlebar electrics. That day, I draped a third bag across the rack, just to break the force of the rain before it hit the motor. But there was no cover around the pedals/chainwheel.

 

My bike gave me no problems, then or later. Maybe I'm just lucky, or maybe my simpler sensor is less vulnerable to water. (To be honest, I've never even looked for the pedal sensor - don't know what it looks like.)

 

Mary

As I replied to Rooel above, the external pedal sensors aren't vulnerable to damp, but I don't know what type UM use.

 

The external type consist of a disc on the pedal shaft just behind the chainwheel which has a ring of tiny magnets in it which you can see if the surface of the disc is clean. Against that is a tiny reading element which is a Hall effect semiconductor (a form of transistor) with a cable leading from it to the controller. The reading element is thoroughly sealed against damp since a magnetic field can carry through an insulating layer.

 

The infra red torque sensing elements Haku mentioned cannot be so easily sealed of course since they must have line of sight to work.

 

If a dehumidifier is available, here's the most effective and rapid way to dry out damp electrics.

 

Bring the bike indoors into a small room. Place a fan heater about 2 feet away from the likely electrical area affected, running on 1 kilowatt. Two feet away on the other side, place a dehumidifier drawing air away from the bike. Then close the door on it. That sets up a loop of warm air which is progressively getting more and more dry due to the dehumidifier, and I've found about half to one hour usually does the trick.

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Hi.

Could You Give Me Any Idea Where I Can Obtain A Pedal Sensor Like The One You Describe As Mine Has Split In Two So I Cant Use My Bike At The Moment,i Live Near Blackpool And Nobody Seems To Sell Spares For Electric Bikes Round Here.

Thank You Tepbowl

water proof ?

 

Not just UM though Haku, many e-bikes hate rain.

 

Bikes are very vulnerable, much more than motorcycles where there's plenty of protection from tank, radiator, cowlings, engine etc to hide electrics behind.

 

Should be ok after a thorough dry out, but it would be a good idea to proof all the vulnerable points when you have a chance, and certainly before the winter.

.

what do you do to "proof" all vunerable points please.

Have a look at this general advice on my Torq site Keith, much of it applies to the Quando as well, though the newer bikes like yours are much improved.

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thanks for that, as i sifted through for something to read as the day got longer and longer and no new postes for hours,i forgot most useful daily tips are on them pages which i read befor..will bear in mind befor next question.

keith

Regarding your new Quando Keith, one thing caught me out.

 

I'd had mine with me down in Dorset, riding it on muddy unmade roads, afterwards gently hosing it down without any problem, it still running perfectly. However, I put it into the car laid down on it's side before it was totally dry, ready for the drive home.

 

At home it was no longer working, since the cable that leads into the controller made a convenient path for water drops to run along into the controller when the bike was flat on it's side. Thoroughly drying out solved that of course, but it's something to bear in mind.

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peda l sensors

 

hi,

circular pedal sensor incorporating several small magnets that fits on crank shaft,can anyone advise me where i might be able to obtain one of these.seems to be a lack spare part stockist round Blackpool area.

 

tepbowl [ new member ]

There are very few spares stockists for electric bikes anywhere Tepbowl. A specialist part such as you require will normally only be available from the importer or distributor of your particular brand. If thats not an option and the part is not repairable then all you can do is to try and find a generic part by searching for "pedal sensor ring" or similar. For anyone with the necessary skills, making a new one from aluminium would not be difficult.

Urban mover pedal sensor

 

Hi, I had various issues, but it seemed to be more to do with the 3 wire connector for the pedal sensor than the sensor itself. Taking it apart and remaking it 10 times did the trick. I have re-jigged my bikes controls to make them much less susceptible to bad weather, and got rid of the sprung contacts between the battery and control box, for a proper connector. The UM sensor consists of two emmiter/receiver pairs (LED or IR), and an annular ring of flags that break the beams. They need the two pairs to detect when the pedals are going forwards (vs backwards). I assume that the 3 wires are the supply (+ and -) and then the output. There is circuitry in the sensor, so I expect that the speed is decoded to an analogue output within the sensor. The output is probably supposed to be proportional to pedal speed, however in reality it seems that as soon as the pedals are turning forwards at all, a full signal is output, causing maximum power to be delivered. With all my mods, my UM36 is going great now. The pedal sensor is defnitiely the weak point on my bike, it seems like a simple problem to detect motion in one direction reliably. I agree with a previous posting that I read, that the manufacturers are getting the users to do the testing.

regards, Jonathan.