2015 Stromer ST1 Torque Sensor Issues?

[David Hutches]

Relatively new (~1 month old) Stromer ST1 with just a little over 300 miles on it. From the start of the commute home today, the motor assist became very erratic: Assist, no assist, assist, no assist, etc. If I were to guess, it seems like an issue with the torque sensor, as the motor appeared to work okay when pressing hard on the pedals, but with just normal pressure (which had worked up until this afternoon), the assist from the motor alternated on and off in a way that made the bike really unpleasant to ride. There doesn't appear to be anything physically wrong with the sensor, so it's a little disturbing that essentially a new bike is already starting to have these kinds of issues. Any thoughts?

 

[CptPalmer]

Check the sensor sensitivity setting. Here is a thread that has all the codes listed with the one I am implying you check out. http://electricbikereview.com/community/threads/stromer-st1-codes.1521/

 

[David Hutches]

Check the sensor sensitivity setting. Here is a thread that has all the codes listed with the one I am implying you check out. http://electricbikereview.com/community/threads/stromer-st1-codes.1521/

Configured that when I first got the bike, and up until yesterday it was behaving normally. Did a test this morning with and without panniers (I read elsewhere speculation that heavier panniers can interfere with proper torque sensor operation) and the bike's behavior was just fine (for the entire 14 mile commute). Will see how it behaves on the commute home today. I'd also read that some have seen this behavior because of a faulty rear brake sensor, and as a stopgap measure, they simply disconnected the sensor until they would get it replaced.

 

[Nebster]

Did you turn the bike off and back on when you encountered the problem? I've had something kind of like this a few times if I'm accidentally putting a little torque on the crank when it boots up. The computer takes an initial reading to zero the strain gauge.

 

[David Hutches]

Did you turn the bike off and back on when you encountered the problem? I've had something kind of like this a few times if I'm accidentally putting a little torque on the crank when it boots up. The computer takes an initial reading to zero the strain gauge.

Didn't try that at the time I was having the problem, but obviously turned the bike off and on between the afternoon commute and the morning commute, so that may have fixed the problem accidentally. Hadn't thought about the initial sensing phase; good call. Will be more mindful of pressure on the pedals when the computer is turned on, and if I run into the erratic motor assist behavior again, will try the power cycle option to see if that works. Thanks!