Bypass crank sensor on an eco stepper.

[Mark Drake]

The chain jumped off the pedal crank yesterday and mashed the pedalec sensor.

Is there a way to bypass the pedal crank sensor while I try and source a replacement?

Regards,

 

[Deleted member 4366]

Unplug it from the controller. The controller is in the compartment under the battery. You have to remove one side of it, which means the two screws in the middle and several tiny ones around the outside.

 

[Mark Drake]

Unplug it from the controller. The controller is in the compartment under the battery. You have to remove one side of it, which means the two screws in the middle and several tiny ones around the outside.

Thanks.

Would the motor then be controlled by the on/off button on the handlebars.

I would still be able to get power assist would I ?

 

[Deleted member 4366]

It'll work if you have a throttle, but not without.

 

[Kuorider]

You can get a new part from Panda bikes, they also supply a throttle. The wires for the throttle are in the loom at the controller. Parts are cheap. Any problems fitting post back here for info. http://www.pandabikes-shop.co.uk/accessories/4586709628 Panda are uk based and reliable.

 

[Mark Drake]

Panda Bikes look good, thanks for the pointer.

Not sure if I should ask these questions first here before I ask Panda.

The PAS sensor for my ECO Stepper looks like it needs a crank shaft puller to allow the mounting plate to be fitted.

Where can I get the special puller from?

Question on the thumb throttle.

Presumably it is spring loaded. When you release it, does it cut the power off, or does it go full power?

Fitting a throttle and using the pedelec power sensor does seems a bit of a grey area. Has anyone done it on an ECO Stepper?

 

[Deleted member 4366]

You'll need the bottom bracket tool too.
http://pages.ebay.com/link/?nav=item.view&id=281725384609&alt=web

 

[Kuorider]

The throttle springs to 'off' , it overrides the pedal sensor at low speeds, if pedalling fast it makes no noticeable difference.The throttle may need a simple wiring change if the plug is not a match. It's red to red, black to black and remaining wires to each other.
The bike needs to be rolling forwards before applying throttle, it won't pull from a standstill . I have done two eco steppers and both work perfectly. If you are not confident doing the work, a local bike shop may help, or post your location and there may be another member near who could help.
All this work is quite simple but all us codgers were doing this stuff as lads with grandpas to keep us right.
Panda do a clip on version of the pedal sensor which needs no stripping work, scroll down the page link I posted to ' easy fit pas' they have a video there on how do fit. Well worth the extra few quid Video here .

video here

 

[Mark Drake]

Thank you Kuorider, your post sheds a lot of light on the subject. It is most helpful. Thank you for your patience and time.

This is my first electric bike and was never any good at electrics, hence the very basic questions I ask. I rode a Brompton for the previous 15 years in the UK and in Belgium and the Irish Republic, but now my knees can't take the strain.

OK, so if I had both PAS Pedalec and a throttle working together, I would set off with the PAS enabled and the throttle just open a little. When the PAS kicked in the power would be controlled by the throttle. Gradually opening the throttle would increase the power to the motor. I would need to keep the throttle open as log as I needed the power assist. If I closed the throttle and/or stopped pedalling, or used a brake, or hit the power off button, the power would switch off.

Am I close?

I am located in North Lincolnshire.

Thanks also to D8veh. I've bought the tool you pointed me at this afternoon. You can't fit the ECO Stepper original PAS without it. It's good insurance.

I have given myself a bit of time replacing the PAS Sensor by a bit of super glue. Don't know how long it will last.

Bit of a design flaw when the chain jumping off the sprocket chews the PAS Sensor up. The screws holding the sensor to the backing plate had been chewed out and lost, the baking plate bent and the red plastic sensor had been chewed. I'm thinking of protecting the sensor with a chain catcher plate of some sort.

 

[Swytch Bike]

You can get a new part from Panda bikes, they also supply a throttle. The wires for the throttle are in the loom at the controller. Parts are cheap. Any problems fitting post back here for info. http://www.pandabikes-shop.co.uk/accessories/4586709628 Panda are uk based and reliable.

Thanks Kuorider for linking people to the product page - we've actually launched a new shop recently @ www.pandaebikes.com
So the best place for people to go now to get the easy fit PAS is here:
http://www.pandaebikes.com/product/electric-bicycle-e-bike-pas-pedal-assist-sensor-easy-fit/

It's now slightly cheaper (£17) - however due to recent demand we are fresh out of stock until next Wednesday 29 July so anyone buying one should be aware there will be a short delay if before the 29th July.

 

[Kuorider]

Close, you are bang on. using it this way will give you about 20 miles. I fit the disc and sensor on the left hand side well away from chain damage. Not a single problem in over a year of use on both conversions with this set up. (I stripped cheap hoppers for the' kit').
I locate the sensor disc against a pressed on brass ring, then two or three O rings to hold it firmly in place behind the crank, thus ensuring constant alignment with the sensor. I originally considered making up a spun metal cup to protect the unit but it proved unnecessary as both are unmarked and still in perfect condition. Why these are usually fitted behind the chainwheel makes no sense as you have found out. Break this in that location and you are stuck.
I am too far from Lincolnshire to be of help but have fond memories of RAF Marham and jolly days in Kings Lynn and dog outings in Wootton Woods followed by a pint in The Mucky Duck.

 

[Kuorider]

I should point out that my connection with Panda is as a satisfied customer and no other link exists. They do what they advertise. Others should take note.

 

[Mark Drake]

Thank you Kuorider, I finally understood how the throttle and PAS work together. Your help is much appreciated.

Yup, it's bomber command country up here. You have to really concentrate on your driving when the red arrows overtake you at hedge height.

If my super glue fudge fails I may want to run the motor on the throttle alone with the PAS unplugged at the controller for a short while. Especially as we seem to have caused a temporary parts shortage. Have you tried that configuration?

 

[Mark Drake]

Hi Kuorider,

Does the following scenario make sense to you?

If you fixed the throttle to go to full power when you released it, would this mean that it cutting the power would act exactly the same as PAS alone?

Stopping the motor would be by operating either brake, stopping pedalling or pressing the stop button.

You would then only need to use the throttle when did not want full power.

Taking your hand off the throttle to indicate turning would not cause the power to cut off when you might not want it to.

Regards.




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[Kuorider]

Don't alter the throttle direction. Just start pedalling and add a bit of throttle until you get the assist level you want. If you need the throttle to hold a given position use a twist type and push the handgrip up against it to give a bit of friction, and hold it in place. Touch a brake or roll off the throttle to power down. If you have ridden a motorbike this will be natural. I built one for an elderly lady and she uses it this way with no problems .Being a former motorcyclist and pilot she has no issue with control. The method you suggest would leave you on full power/speed constantly and could be unsafe as the control actions would not be instinctive. You can do this with one hand, brake with 3 fingers,hold the grip with index finger and roll of power with thumb.