Wisper cutting out

[Phil the drill]

Hi
I have a problem with my 905se. On way way to and from work recently it has cut out without warning. In all cases the battery lights remain lit with either all three lights or at least two of them. It usually happens on the way home, when the battery has done some work but I don't think the battery is the problem (at least I sincerely hope not). The fault always follows the same pattern. If I pedal along with the motor in pedelec mode and then stop pedaling or switch the motor off for a while (eg going down a hill or stopping to negotiate a narrow bend with oncoming traffic) when I start pedaling again the motor will not start. In addition the throttle also fails to operate the motor, despite the power indicators. If I stop and fiddle with the pedelec magnetic disc it usually starts again. Despite this I can find no problem with the sensor disc - all the magnets are there and the clearance seems OK with the sensor. It's unlikely to be loose sensor wires, as it restarts even when I haven't touched those - in addition I assume that the throttle should still work even if the pedelec system was not working properly(?). I don't think that the stopping and fiddling around is a red herring - just allowing the battery to recover, as pausing with the battery switched off doesn't seem to fix the problem. It is getting worse - much more frequent.
Any ideas anyone? I'm getting nervous about commuting to work on it as it would be pretty awful (and very slow) to pedal half my daily commute on a dead e-bike - I'd much rather be on my hybrid under those circumstances but I can't work if I go that way as I get far too hot and sweaty getting up the hills and I don't have a shower facility (or time to use if I had) at work.
Incidentally the bike is just under a year old and has done in the region of 1500 -2000 miles.

Thanks, Phil

 

[Footie]

Hey Phil,
This may sound like a daft reply but have you thought about disabling the pedelec mode as a test?
From the way you describe it sounds like it's the pedelec mode but as you say it all looks ok - so it's a mystery.
At least then you will know for sure.
Just a suggestion

PS: I know it's not a Wisper but my pedelec mode has always been disabled on my MTB style bike.

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Thankfully, not something I have to worry about
.

 

[Phil the drill]

Hey Phil,
This may sound like a daft reply but have you thought about disabling the pedelec mode as a test?
From the way you describe it sounds like it's the pedelec mode but as you say it all looks ok - so it's a mystery.
At least then you will know for sure.
Just a suggestion

PS: I know it's not a Wisper but my pedelec mode has always been disabled on my MTB style bike.

BikeWires on Flickr - Photo Sharing!

Thankfully, not something I have to worry about
.

Thanks for the reply, but on the Wisper, short of disconnecting the wire from the sensor there is no way to disable the pedelec mode. I will try this, but since the fault is intermittent I won't be certain (for a while) if it's the problem! I am concerned though, that when it does cut out the throttle also fails to operate the motor.

Cheers Phil

 

[The_Bike_Whisperer]

Hi Phil,

My Wisper recently lost all power in Pedelec mode, however I still had power if I used the twist grip, which I know is different from your problem. My issue was solved with a new pick-up sensor which was a 10 minute refit. It may be worth checking that the brake motor cutout switches are releasing ok, I believe you can disconnect the wiring on these individually, then go for a run to see if the problem is cured. Just remember that the motor cutout switch is deactivated for safety reasons.

Best Of Luck
John

 

[Straylight]

Hi there!

The only thing I can think of that would produce the symptoms you describe, is an intermittent fault on one of the brake cut out switches. This would leave the power lights lit, but prevent use of the motor. Still, it's a bit odd that the fault follows such a precise pattern, unless you habitually use the brakes in a certain way at the points when the fault occurs.

I'd try continuity checking the switches with a meter, and pull the brakes with varying amounts of force to try to recreate the conditions of the fault. I don't know if the switches are normally open or closed, so whether you'd get continuity before or during braking, so to be thorough, I'd compare the switches against one another.

Thinking it through, if it were a problem in wiring for the brake cut outs, then, from what you've described, the fault is most likely to be a loose connection at the controller end of the wiring loom, so I'd start by tuning the bike upside down, removing the plate that is beneath the controller, and inspecting all the connections from the wiring loom to the controller, making sure that they're all seated properly. BTW, if your bike is like mine then you should have one pair of connectors unconnected (purple wire, I think), as connecting this disables the throttle.

Hope all this rambling nonsense helps!

 

[Wisper Bikes]

Cutting out

Hi Phil

I would agree with Straylight it may be a brake switch that has an intermittent fault. I would suggest you contact Norman at service@wisperbikes.com and he will certainly sort out your problem.

Don't worry even if it is the battery as the bike is less than a year old you are still under warranty.

Best regards David

 

[Phil the drill]

Aha, the brake switches, I forgot about them. I've had that problem before too, so no excuse for not checking them! On the other hand I'm not sure how fiddling around with the pedelec sensor disc would fix that Still that bit may just be a coincidence of timing.... If they are a problem I'll probably just dump the switches and not bother with them. As the brakes themselves now work well and motor overrun is pretty small they are, in reality, of minimal use .

Many thanks, Phil

 

[Straylight]

It struck me that by fiddling with the sensor, you may have been inadvertently shifting the cabling onto the controller, and re-establishing a tenuous connection from the brake switch. This was why I suggested an inspection of that end of the loom. Anyway, I hope this helps.

I personally find the brake switches of use to counter the sensor delay in the pedelec cut off, but I guess it all depends on individual riding style

 

[Mussels]

Thanks for the reply, but on the Wisper, short of disconnecting the wire from the sensor there is no way to disable the pedelec mode. I will try this, but since the fault is intermittent I won't be certain (for a while) if it's the problem! I am concerned though, that when it does cut out the throttle also fails to operate the motor.

Cheers Phil

The pedelec is easy to disable, simply slide the disk slightly out along the spindle toward the crank.
I agree with the brake switch theory, when the lever is released it then pushes the switch closed. If for some reson it isn't springing right back straight away then it could delay the motor being available.
Out of interest are you using the new brake levers?