1st ride on new ST2 got heat warning??

sms

New Member
Hi all
I just picked up my Stromer ST2 today and took it out for a ride. At the top of the hill I got a warning that the engine temp was high and noticed motor support falling off. I stopped, turned around and rode back down the hill and everything seemed fine from there. Climbed in pretty big gears all the way up switching between level 2 and 3.

The hill I rode was pretty stout:
- 1224' elevation gain over 3.5 miles
- average grade of 7.2%
- grade was about 17.8% when the power dropped and warning came up
- FEIT index is 2.72
- Drained 24% of the fully charged battery on my ~10 mile inaugural ride FWIW

I've ridden this hill in my road bike and it is really, really hard which is why I wanted to use it to test my new bike. I called the shop to ask if I should be concerned since the salesman told me prior to buying the bike that he had never had anyone overheat the motor. He said to watch it and keep him in the loop if it happens again.

Does this sound normal? I really have no idea but am concerned since I bough this to be my commuting bike. The ride to work is about 7 miles but 3 are up a long and steep hill. Doing the test commute tomorrow. Would appreciate any insights.
 

smitty

Active Member
Hi all
I just picked up my Stromer ST2 today and took it out for a ride. At the top of the hill I got a warning that the engine temp was high and noticed motor support falling off. I stopped, turned around and rode back down the hill and everything seemed fine from there. Climbed in pretty big gears all the way up switching between level 2 and 3.

The hill I rode was pretty stout:
- 1224' elevation gain over 3.5 miles
- average grade of 7.2%
- grade was about 17.8% when the power dropped and warning came up
- FEIT index is 2.72
- Drained 24% of the fully charged battery on my ~10 mile inaugural ride FWIW

I've ridden this hill in my road bike and it is really, really hard which is why I wanted to use it to test my new bike. I called the shop to ask if I should be concerned since the salesman told me prior to buying the bike that he had never had anyone overheat the motor. He said to watch it and keep him in the loop if it happens again.

Does this sound normal? I really have no idea but am concerned since I bough this to be my commuting bike. The ride to work is about 7 miles but 3 are up a long and steep hill. Doing the test commute tomorrow. Would appreciate ight be better for the motor as well as the batteryany insights.


I have been riding in pretty big gears and doing likewise (levels 2 & 3) on some long hills. I just started using the smaller chin ring a bit, kind of trying not to use level 3 as much. That feels a bit more natural and I think may be better for the motor as well as the battery. I have not experienced to this point any sort of warning regarding over-heating the motor.
 
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Ann M.

Well-Known Member
@smitty, is it hot and humid where you're riding? If so, that can make it harder for a motor to dissipate heat while climbing a steep hill. Your idea of using a smaller gear is more optimal for the bike and your knees.
 

smitty

Active Member
@smitty, is it hot and humid where you're riding? If so, that can make it harder for a motor to dissipate heat while climbing a steep hill. Your idea of using a smaller gear is more optimal for the bike and your knees.

central NY in the Finger Lakes region, plenty of hills and the weather has been really warm this summer, along with the humidity. My longest ride to date has been 45 miles or so on an incredibly hot day (I didn't go out early enough in the day). Using the lower gearing has helped me stay out of level 3 assist. I'm pretty sure that it is indeed better for the battery and motor and for sure on the knees.
 
I have a 2014 ST-1 and have the same issue. I ride in the north Georgia mountains and on one particular climb, 7 miles, 1800' vertical gain, 14% grade in places, I always get a HEAT message. Talked to tech support in San Diego and they feel this is not a malfunction but simply making the motor work to hard. I'm a little surprised that you are getting that same issue with an ST-2 (electronic outside the hub), the ST-1 has the electronics inside the hub.
 

Neil

Member
I get the message routinely when I am climbing the last 4km of my commute. I can almost predict when it will pop up. I just dial back to level 2 assist and keep going. I have never had it pop up twice. I believe it is just a warning to protect the motor. The St 2 protects the drive by automatically dialling back the assist as needed from my understanding.
 
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sms

New Member
Thanks for the responses. Glad to hear this is to be expected. Need to learn the bikes limits since I know my own

The temp the day I rode was in the low 80s and no/low humidity. Must have been some combination of too much hill for too long at too high an assist level and not enough contribution from me.

Tried my real commute ride today-- no prob. Actually amazing! I took it easy on the assist level opting for Eco on the way there except for a long 2 mile 7ish% grade segment but in a mid gear. Grinned all the way us cruising at 14-19 mph. Used <<< recoup on the steeper and even longer backside which kept me moving briskly and under control but it didn't seem to do much to recharge the battery.

Rode a lot harder and with more assist on the return trip to see if I could get that warming again. Not prob-- just went a lot faster.

Uploaded my ride to Strava just to see-- edited the ride to ebike after discovering I set 10 segment KOMs. After the edit I don't show up on the leaderboard anymore.

According to Strava I gained 2122 ft of elevation on the 16 mile round trip and averaged just over 20 mph. It didn't take too much longer than my typical drive time. Looking forward to going to work tomorrow!
 

Neil

Member
The "real" cyclists get a little upset when we steal all the KOM's. My commutes upload automatically through Garmin Connect and then syncs to Strava. If I don't go change the type of ride to E-Bike, it upsets the apple cart.... I usually do it right away. I am amazed though how fast some of those KOM's are. I cycle on a road bike as well and I doubt some of those are genuine.