Stromer ST1 motor vibration when cold

[boolibasa]

Hello, I am in Vancouver, Canada and got an ST1 Stromer (I am second owner, but when I bought it it looked like new). Bike runs very well, but only after it 'warms up'. As I have some basic understanding, I tried to reach Stromer customer service in San Diego to see if they heard anything like this with this model:

- When starting from cold (after over night parking and charger removed) in any assist, the motor vibrates with very low frequency (5-10 Hz); the assist is dim.
- After some time (10-15 min) of riding (with power assist) suddenly it starts working smoothly. The time depends on how steep the terrain is, i.e. how much effort the bike puts (or based on the power assist level).
- Also the brake recharging system does not work when cold, only after the bike warmed up (and I left the battery overnight with low charge to test this). It was working the night before when I rode the bike home.

Stromer suggested I should look at the torque sensor (clean it or re-seat all connectors). Anyone had this issue before ? Appreciate your help as I like the bike very much

 

[Ann M.]

The cold temperature of your battery may be the reason the motor is chugging when first started or on hills. Perhaps storing the battery indoors overnight or when you're done riding will help. Also, consider a cover for your battery while riding on a colder day; neoprene seems to be a good material. @Ravi Kempaiah may have mentioned one in an earlier post.

Perhaps it might be a good idea to have a shop test your battery, too. The overall voltage may be starting to be a bit on the low side just due to age and use.

 

[boolibasa]

Thank you - Yes, the plan is to take it to MEC who handles service here, also just to mention here, this phenomenon happens even in hot summer days when the bike was idle for a longer time....