ST1 Power flcuation

eBikeGuy

New Member
Have an ST1 Platinum, and am experiencing some strange power fluctuations. Motor assist is set to 50, while I have the LCD controller set to city. I'll be pedaling along just fine, tun all of a sudden, it feels as if a parachute is hanging off the back of the bike slowing me down. 20 seconds later all is fine..then after another 30 seconds or so...out goes the parachute. I've change the assist level to Tour and Power, but this behavior is still present. It's very frustrating to be going along just fine, and then have the bike feel like it's fighting me. Has anybody else experienced this?

Thanks
 

opimax

Well-Known Member
are there any noises? Is the bike being pushed hard ? has your chain ever been cleaned and lubed? does turning it off and back on change anything?large amounts of mud or dirt near the torque sensor? is there an over heat message on the display? does the battery level effect this?
 

Marko

Active Member
Maybe there is problem with power feed to the motor. Have you checked cables are ok between battery and motor. During these parachute events is the controller display showing the correct mode still.
 

opimax

Well-Known Member
the reboot for a Stromer as I understand it , remove the battery, remove the battery in the display or at least disconnect it, you can disconnect the rt brake lever connector, and I think 4 connectors to the motor hopefully under the elastic/Velcro Stromer covers by the rear wheel , left side. Let it set for a few minutes and reconnect all and test. Sometimes the the rear brake handle may not fully return to the rest position and it will not have power but the display should change to recoup mode
 

JoePah

Well-Known Member
Have an ST1 Platinum, and am experiencing some strange power fluctuations. Motor assist is set to 50, while I have the LCD controller set to city. I'll be pedaling along just fine, tun all of a sudden, it feels as if a parachute is hanging off the back of the bike slowing me down. 20 seconds later all is fine..then after another 30 seconds or so...out goes the parachute. I've change the assist level to Tour and Power, but this behavior is still present. It's very frustrating to be going along just fine, and then have the bike feel like it's fighting me. Has anybody else experienced this?

Thanks

I notice on my Stromer when the battery level goes below 40% that the power assistance is reduced, I guess to extend range. So my guess would be is that your battery might be getting some voltage sag, and the controller is just responding. When you let up, the sag disappears.

Does this problem happen with a fully charged battery? If so then you've got a dying battery or a faulty controller. If it happens when the battery is more than halfway discharged or when you going up a hill, it might just be a weak battery...

I don't rmember what the Motor assist level is from the factory.. Is it 50?
 

Gus

Active Member
Have an ST1 Platinum, and am experiencing some strange power fluctuations. Motor assist is set to 50, while I have the LCD controller set to city. I'll be pedaling along just fine, tun all of a sudden, it feels as if a parachute is hanging off the back of the bike slowing me down. 20 seconds later all is fine..then after another 30 seconds or so...out goes the parachute. I've change the assist level to Tour and Power, but this behavior is still present. It's very frustrating to be going along just fine, and then have the bike feel like it's fighting me. Has anybody else experienced this?

Thanks
What are the little assist level arrows in the bottom right corner of the display doing when all this happens? Do you go from 1-3 arrows to no arrows when the assist goes out or do you have no assist but still have the same level of arrows?
 

eBikeGuy

New Member
Thanks for all of the replies. Let me respond:
1. Chain is clean and lubed properly. No mud, dirt, or anything like the such.
2. Battery is about 85% charge when this happens. Never happens on the way to work in the morning, only when I go home in the afternoon.
3. No noise
4. Spoke are good.

Took the bike to work this morning...no problems. Then, went to grab lunch..using my bike. When I got to the restaurant I put the bike in 'Locked' mode. On the way back to my office, after about 1 minute of riding, it started feeling like the rear brake was being applied. Pulled over, turned bike off and then back on.....mildly better.

I'm leaning towards the reason 'optimax' suggested.

Will pay more attention to the control display on the way back home this evening.

Thanks for all of the responses
 

eBikeGuy

New Member
Riding home this evening I took notice of the little arrows.

Scenario 1: Motor assist 50
24 km/h
eco mode
mostly no arrows, but sometimes one arrow

Scenario 2: Motor assist 70
28 km/h
eco mode: mostly no arrows, but sometimes one arrow
city mode: one arrow, but sometimes two arrows

Scenario 3: Motor assist 70
34 km/h
power mode
mostly two arrows, but sometimes three arrows

When pedaling down hills, in any mode or motor assist, if I stop pedaling the bike slows down as if in recoup 1, although it is not displayed. If I stop pedaling on the flat, the bike will stop in about 100m from a speed of about 25mk/h.

I am definitely getting a workout. LOL
 

JoePah

Well-Known Member
OH that doesn't sound right...lol.. After reading that i remember putting my bike in RECUP1 by mistake once and it was a total drag. Must be for going down hills only, cause it'sa PIA on flats.

With the system turned OFF, can you pedal the bike normally, or is there a lot of drag?
 

Cuong Tran

New Member
Have you try disconnecting the battery? I have somewhat of a similar problem but feels a little drag. After I do a quick disconnect to the battery. The bike is back to normal again.
 

Dave Delaney

New Member
I have an ST-1 Elite for a little over a year. The same drag symtom has happened to me twice. I was in "City" mode peteling at 15 mph on level. Temp. was about 70.

I think in might be a firmware error with the controller. My firmware revs are: 2000 = 088, 2001 = 076. Dealer service said no new firmware.
 

eBikeGuy

New Member
OH that doesn't sound right...lol.. After reading that i remember putting my bike in RECUP1 by mistake once and it was a total drag. Must be for going down hills only, cause it'sa PIA on flats.

With the system turned OFF, can you pedal the bike normally, or is there a lot of drag?


Lot's of drag!
 

eBikeGuy

New Member
Thanks for all who responded. As I have now gone for a business trip, I will not be home for thwo more weeks. I will do the battery disconnect thing, as well as check my firmware levels.

Again, thaks for all who responded..
 

eBikeGuy

New Member
Okay everybody..I am back from the business trip hoping that everything is okay with my Stromer. Last evening I went for a ride, and noticed the problem again. However, this time I was able to correlate it to specific activity. On the first half of the ride, about 20km, I had no problems at all. Most of the ride is very flat, except for the last 1.5km. It is the last 1.5km that is a steep climb..not too steep, but I still have to work. I put the bike in Power mode, the chainring in the middle, and use the 4th biggest rear cog. After about 5 minutes of climbing I get to the top, wait a few minutes, takes some pictures, and the head back down; coasting all of the way at approximately 60km/h. It is now when I start experiencing problems. With the bike still in Power mode, I have a VERY hard time getting past 30km/h. Road is completely flat, and the wind is at my back. It again feels as if the rear brake is applied and released....over and over. However, when I stop peddling, I get quite a surge for about two seconds.

This morning, on my way to work I experience no problems whatsoever...only 10km of flat terrain.

Forgot to add: The torque sensor setting is 40
 
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eBikeGuy

New Member
Was in Oberwangen yesterday, and explained the issue I am having with my ST1. I was told the problem is definitely, without a doubt, the torque sensor; this is a known issue. Was given a new torque sensor to install.
 

Cuong Tran

New Member
Was in Oberwangen yesterday, and explained the issue I am having with my ST1. I was told the problem is definitely, without a doubt, the torque sensor; this is a known issue. Was given a new torque sensor to install.

That good to hear identified the problem.

Keep us updated....
 

eBikeGuy

New Member
Problem fixed. An additional note...the torque on the rear axle must be exactly 70nm. Too much...problems. Too little..problems. The new sensor with the proper torque has fixed my problem.