ST5 moving by itself

[Petropoliskhan]

Hello all,
This afternoon as I was leaving working, I moved my st5 a few feet as I always do from its parking place and was surprised to feel it moving by itself. As if the walk assist mode was being activated. I had not activated it (never use it).
The forward momentum was more powerful than that of the walk assist even at its highest setting. I immendiately hit the brakes and it stopped. When I tried to move it again a few inches I started rolling again. This was not so powerful that a quick brake grab couldn't stop. I never started rolling by it self just kept rolling and slowly accelerating...
I got on the bike and rode my usual commute back home. During the ride it sometimes felt as if ,when freewheeling it wanted to continue accelerating. Upon arrival at home I attempted to reproduce "the self propelling experiment" but everything was normal. I forgot to calibrate the torque sensor. Will do that if it happens again.
I remember reading on the dutch Stromer forum that this could happen if the rear wheel isn't properly torqued.
Anybody have a similar experience with their Stromer?

 

[bluecat]

When I tried to move it again a few inches I started rolling again. This was not so powerful that a quick brake grab couldn't stop. I never started rolling by it self just kept rolling and slowly accelerating...

Usually, such things might happen after some manipulations in the area of the rear axle. A smooth baseline shift is also common, e.g due to temperature differences. Before you change anything, check the voltage values from the sensor. Active value should be slightly above base value.

 

[Petropoliskhan]

Usually, such things might happen after some manipulations in the area of the rear axle. A smooth baseline shift is also common, e.g due to temperature differences. Before you change anything, check the voltage values from the sensor. Active value should be slightly above base value.

Hi Bluecat, thank you for the reply. Could you please explain the procedure to access the torque sensor values menu and the values I should look for.

 

[Johnny]

Hello all,
This afternoon as I was leaving working, I moved my st5 a few feet as I always do from its parking place and was surprised to feel it moving by itself. As if the walk assist mode was being activated. I had not activated it (never use it).
The forward momentum was more powerful than that of the walk assist even at its highest setting. I immendiately hit the brakes and it stopped. When I tried to move it again a few inches I started rolling again. This was not so powerful that a quick brake grab couldn't stop. I never started rolling by it self just kept rolling and slowly accelerating...
I got on the bike and rode my usual commute back home. During the ride it sometimes felt as if ,when freewheeling it wanted to continue accelerating. Upon arrival at home I attempted to reproduce "the self propelling experiment" but everything was normal. I forgot to calibrate the torque sensor. Will do that if it happens again.
I remember reading on the dutch Stromer forum that this could happen if the rear wheel isn't properly torqued.
Anybody have a similar experience with their Stromer?

Same thing happened to me. It is a problem with wheel installation and the right torque. Check the torque of the axle should be 25nm according to manual.

I was also recommended to grease on the threads and head of the axle where it contacts the frame when wheel is re installed. Prevents torque sensor from getting stuck(especially with temperature changes).

Also recalibrating should fix the problem (at least temporarily).

Mine went away eventually without reinstalling the wheel.

 

[Petropoliskhan]

Same thing happened to me. It is a problem with wheel installation and the right torque. Check the torque of the axle should be 25nm according to manual.

I was also recommended to grease on the threads and head of the axle where it contacts the frame when wheel is re installed. Prevents torque sensor from getting stuck(especially with temperature changes).

Also recalibrating should fix the problem (at least temporarily).

Mine went away eventually without reinstalling the wheel.

Hi Johnny, I will do the sensor calibration and check the torque.
Best regards