Woosh TSDZ2 - (very) intermittent power

[seec]

Hi all, I have a350w 48v TSDZ2 from Woosh mated to a Specialized Allez. I bought the kit a few months ago, installed it with only minor troubles, and have ridden 200+ miles on it so far.

I haven't ridden it for 2 weeks or so, but fired it up today to get a run to the grocery in. The battery was sitting on the charger the whole time, so I put it on the bike and tried to go, but there was no power. The screen powers on, the speed reading is correct, and when I apply torque, the motor makes noise like it's trying to turn the wheels, but there's no assist. When I hold the breaks and push on the pedal, the engine is trying to push off. I played with it a ton today, and every once in a while after multiple restarts, it gives full power for around half a second, then reverts to nothing.

The battery voltage is 54.2. I've unplugged and replugged all cables on the bike to ensure they're seated properly. I re-seated the battery several times. I turned it on and off a shitload.

Any ideas? I'm about at my wits end!

 

[Woosh]

try this first.
1. Go into settings.
2. Enable walk mode.
3. See if walk mode works (press and hold the - buttons for two seconds).
That will test the controller and the gearbox.
https://wooshbikes.co.uk/manuals/VLCD5.pdf

 

[seec]

Walk mode propelled it with vigor - does that narrow it down to a possible issue with the vlcd5?

 

[Woosh]

that may point to the torque sensor.
The torque sensor is self calibrating.
Switch on the LCD, let the bike rest a minute with the LCD on for the self calibration to settle.
Test the speed sensor next.
Switch assist mode to zero (no assist).
Pedal a bit to see if the speed sensor behaves normally as expected.
If it's OK so far, try again with assist on.

Then try to ride again.

 

[seec]

Alright I spoke too soon on the walk mode. It does periodically propel it with vigor, but like when I'm riding, the majority of the time the motor is just buzzing and putting out very minimal power. If I hold the bike in place while this super low power time is happening, the motor tries to push it forward with basically no power then sometimes gets a spurt of power for a quarter second before going back to buzzing with no power again.

This sounds like we may be back to the gearbox/controller issues?

 

[Woosh]

if the motor turns but the bike does not move, your blue gear needs replacing.
That's back to Southend.

 

[seec]

Gotcha, so since its periodically working, the blue gear is stripped and sometimes happens to catch on the non-stripped piece of it?

 

[Woosh]

not necessarily. It's possible that the needles inside the blue cog may have lost their grease and stop rotating correctly.
They need to move from disengaged to engaged.

 

[seec]

This is in the bearing inside the blue gear? So the forward/backward motion he's checking at this point in the video:

right?

It seems like theres two such mechanisms in the motor, one inside the blue gear and one inside the massive drive gear. The blue gear is infinitely easier to reach/replace than the large drive gear's bearing as I don't have a bearing press or circlip pliers, so I might give that one a try first, if that's what you think the issue may be.

 

[Woosh]

you are correct.
the blue gear connects the motor to the main gear, the another one is fitted to the bottom bracket and connects the pedal cranks to the main gear.

 

[seec]

Woosh sent me out a replacement blue gear under warranty, which is as wonderful as their customer service has always been. Unfortunately, that didn't fix the problem

edit: video was misleading/wrong

 

[Woosh]

there are not enough clues in the video to figure out what's wrong with your motor.
The walk mode has a speed limit of 4mph, so the motor starts and stops with the wheel off the ground.
can you ride assisted up any hill with the bike (even intermittently)?

 

[seec]

There's no assist on flat ground or the slight hills around my house, not even intermittently. The only way I can get the assist to work for a half second while riding is to hold the brakes while pedaling for a second, let go, then sometimes I get a quarter to half second of assist.

 

[Woosh]

If you sit on the bike and start walk mode, does the motor drive the bike for any length of time?

 

[seec]

First time I tried it, it propelled me about 3 feet and then wouldnt anymore. I tried a few more times, after about 3 attempts it started going 3.5 - 4mph with me on it. I then tried biking about a mile and it worked fine for the vast majority of that mile, with just one power cut out for a few seconds after a stop.

I have no idea what happened or what changed, but at least for the moment it all seems to be working...

 

[Woosh]

intermittent faults are always difficult to diagnose.