Actually, although I went the new crank-set route, i think getting a 11T free-wheel from Cyclezee is likely to be an easier / cheaper option. I went the 52T chain-wheel route, as I needed to replace my bottom-bracket, but it's caused several problems - had to buy a new chain-guard, have had gear alignment issues and may need a new chain as the tension is rather high using the existing one...

 

Would that be difficult to fit?

Would that be difficult to fit?

 

Easy with the correct tools. You need a chain wrench to hold the freewheel still against the freewheel action while undoing the retaining nut, a freewheel removal adapter for that nut and a suitable size socket spanner:

 

http://www.flecc.co.uk/t/images/cassettetools.jpg

.

Edited September 27, 201213 yr by flecc

Today is Aldi Thursday.. when their gone their gone

 

Although the quality is a bit pants, its more than acceptable for occasional use at the price of £19.99 for the complete kit.

Edited September 27, 201213 yr by Old_Dave

Thank you, that is brilliant

Motor drive problem...

 

Have been looking out for a cheap Cyclamatic without battery, so that I can put my spare 24v Li Ion to some use. Found one on Ebay, but after fitting the batt this afternoon, unfortunately motor drive is intermittent and works on throttle only.

 

I've been through the wiring harness with a meter and did a visual inspection. There were a couple of abraded power leads and one of the fine wires (motor hall sensor leads?) was broken at the point the wires enter the wheel hub. I soldered and insulated the offending wires, but same result.

 

Anyone come across this pattern before? You can hear the motor trying to turn when the throttle's opened, but 90% of the time it stalls immediately. Giving the wheel a manual spin sometimes gets the motor going, but it's noisy, although it keeps going, once it's going. There seem to be two motor speeds which occur when throttle is fully open - you get one or the other. Throttle works as expected once the motor's spinning.

 

I'm guessing motor hall sensors blown, or an intermittent fault with the controller? Any thoughts / ideas / ways to diagnose the problem much appreciated

Edited October 16, 201213 yr by evendine

Try the connector on the chainstay. The one that's hidden in shrink-wrap.

Thanks d8veh - haven't checked that one - will take a look at it now...

Hmm - seems ok - no obvious water, cleaned it out both sides, checked the rear of the wheel end connector which looks fine and WD'd the whole assembly...

 

Can see the heartbeat LED on the controller, which is flashing.

 

One unusual thing about the loom in the controller casing - there appears to be a 10k mini-pot in series with a fine white wire. Ever come across that before?

 

A connection / voltage test sheet for the rear wheel assembly would be useful - would be helpful to narrow things down a bit. Thought about trying the post-motor connector from the other bike, but it runs direct from the controller to the motor...

Edited October 16, 201213 yr by evendine

Hmm - seems ok - no obvious water, cleaned it out both sides, checked the rear of the wheel end connector which looks fine and WD'd the whole assembly...

 

Can see the heartbeat LED on the controller, which is flashing.

 

One unusual thing about the loom int the controller casing - there appears to be a 10k mini-pot in series with a fine white wire. Ever come across that before?

 

A connection / voltage test sheet for the rear wheel assembly would be useful - would be helpful to narrow things down a bit. Thought about trying the motor post-connector from the other bike, but it doesn't have that connector...

 

Mine didn't have that pot. Is it on the white wire that comes out of the throttle cable, which is the 5v for the pedal sensor? If it is. that might explain something.

 

Are you saying that it works perfectly on throttle. If so, another yhing yo check is the distance of the magnet ring from the pedal sensor isn't too much.

Ah - no, getting nothing at all on pedal assist, which may tell you something. The hall sensor does look a bit further away from the centre of magnet ring than on my other bike although the gap is about the same. Will double check that.

 

Not sure about the pot (whether it's the throttle wire or not) - my other bike doesn't have one. Have tried tweaking it to different positions, but doesn't seem to have any discernible effect (at least on getting the motor running).

 

I just noticed that the position sensor wires on the brakes have been cut and soldered at some point. Checked the voltage across them. One has 5v when brake not applied, 0v when applied. The other is showing 5v in both positions, which I guess should be ok for now, but indicates the sensor needs adjusting.

 

Also checked the motor windings - about 0.4R. Not sure about the motor hall sensors? Not quite sure how they're wired-up...

You didn't answer my questions:

Does the motor work normally with the throttle?

Is the pot on the white wire that comes out of the throttle cable?

Sorry, no the throttle only works intermittently, athough when the motor starts up occaisionally, the throttle works normally...

 

As I mentioned in the original post: 'you can hear the motor trying to turn when the throttle's opened, but 90% of the time it stalls immediately. Giving the wheel a manual spin sometimes gets the motor going, but it's noisy, although it keeps going, once it's going. There seem to be two motor speeds which occur when throttle is fully open - you get one or the other. Throttle works as expected once the motor's running.'

 

The pot doesn't seem to be related to the throttle cable as far as i can see - certainly not linked to it in the loom. The white wires from the pot go directly into the controller.

 

Btw: i've been attempting to check the motor hall sensors through the back of the connector before the wheel with power on, controller connected. Getting constant 0v for all three when spinning the wheel manually, so perhaps either the 5v or 0v line to the sensors is open circuit?

Edited October 17, 201213 yr by evendine

Do a search here or on Endless sphere of how to chech hall sensors. You can't just put a meter on them because they only make short pulses while the wheel goes round; however, you should have constant 5v between red and black.

Hmm - I'm a bit confused - can't find any method other than using a meter and turning the wheel very slowly to allow the magnet to activate the hall sensor, which should give you closed circuit, apparently:

 

Have taken a look at these:

Endless-sphere.com • View topic - Testing and Replacing Hall Sensors in a MAC Motor

http://visforvoltage.org/forum/4194-testing-hall-sensors

http://www.pedelecs.co.uk/forum/electric-bicycles/10830-wisper-faulty-pedelec-sensor.html

 

With the circuit tester approach, i get open circuit on all three (no matter how slowly i turn the wheel) and 5v on all three signal wires when i tried the 'in-circuit' approach (connecting to the back of the connector nearest to the wheel, powered up).

 

If these results are valid, not sure what to do next. Sensor-less controller? Disassemble the motor and replace / double check the wires / sensors?

Sorry, I can't understand at all what tests you've done, but hey don't sound like the ones on ES,so let's go back to the beginning:

First, set your meter to volts and measure between the black and the red thin hall sensor wires. Please report your result.

Next, with your meter still on volts, measure between black and blue; while your probes are still on, rotate the wheel slowly for a whole revolution. You should see at some point 5v and most of the time 0v. Please report the result.

Repeat for black and yellow and black and green.

An unexpected new result from further testing:

 

If you rotate the pedals backwards a bit and then give the wheel a good spin forwards; the motor works every time on the throttle. Very strangely, if you spin the wheel up using the pedals and then pedal backwards the motor kicks in running forwards normally in assist mode, as it were!

 

Can't help thinking that the pedal hall sensor is reverse wired, somehow! (Have checked the magnet ring and the arrows look right). The white wire from the throttle is connected to the red wire of the pedal hall sensor, btw...

Re: hall sensor test questions:

 

Black - red = 5v constant

Black - Yellow + wheel rotation = 5v (no change to 0v during rotation)

Black - Green + wheel rotation = 5v (no change to 0v during rotation)

Black - Blue + wheel rotation = 5v (no change to 0v during rotation)

The magnet disc is back to front. Take it off and flip it.

 

The Cyclamatic pedal sensor works backwards when compared with standard ones, so maybe sommeone bought a new one and didn't realise.

 

That potentiometer must be on the speed limit wire in attemt to change it, but I'msure that can't work.

 

Can you post a picture of the controller and wires? It wouldn't surprise me if the controller was changed, which would account for the backwards pedal sensor.

Can you check again the black and red hall sensor wires takking notice of polarity - so put your black probe on the black wire and red on red, and then check whether it's + or -5v. It could be that the controller is running sensorless because it doesn't get a hall signal. Hence the bad starting. I need to see a photo of it.

Will do - I'll go and take a pic now and re-check the motor hall sensor power supply lines...

Another thought: Do the colours match on both sides of the hall connector, i.e. black to black and red to red.

Here's a pic which shows the pedal sensor lead at the top right (red black, green) and the throttle lead bottom right with the blue tape. As you can see, the white throttle wire connects directly to the red pedal sensor wire. The mini-pot wires both go directly into the controller.

Yep - hall sensor colours match and +5v rail is correct...

 

Have just flipped the pedal magnet and hey-presto, we now have pedal assist and throttle power

 

Startup on both seems off, though - seems as though the throttle / pedal assist 'on set-point' may be wrong. With the throttle, it's as though it does nothing until you have it half open. With pedal assist, you have to pedal quite hard for it to cut in. Wondering if the pot is related to that?

 

Still need some forward motion on rear-wheel to get throttle power going...

Have tweaked the pot and it seems to effect the 'cut-in' setting on the throttle - will have to take a spin round the garden to see how it works in pedal assist mode...

Looks like a Cyclamatic controller.