Stromer ST2 Pulsing (Please vote)

[Berlin]

First: excuse for my poor english writing

@Mitchell, I am very sure that I have the same problem with my ST2.

I am glad that you defined this problem very well.

Quote from you:
It feels like the assist mode is cutting in and out. For example I will feel the assist for about 4 seconds, then its like assist has been turned down (not completely off) and the peddles have resistance. The peddles require more pressure. After applying that pressure for about 2 to 3 seconds the assist comes back on and there is no longer resistance.

Next point play by me along:
I cycle 80% of the time in mode #2
1) This problem seems to occur more in hotter weather.
2) During a trip - no problem to encounter.
But then, when I stopped at a red light for a few minutes and keep the front and rear brakes pressure hold, sometimes I have/had a little later resistance problems (as described above).
3)Mostly I solve the problem with the next things:
*A little mechanical and electrical 'switch' on the 'gearshift'
*Plus squeezing and wringing at the brake lever and the little cylinder in the brake handle / sensor
*a several times momentarily braking
*pushing a little harder on the peddles

And mostly the problem is solved - This is not funny, but I 'm able to continue cycling.
Currently, as I just indicated braking with rear brake, and I have less problems.

I know someone on an other forum who indicates the same problem.
He told me that his brake sensor was totally wrong mounted from the factory.
I do not know how this is completely resolved, but apparently I never hear of this. - I'm going to ask

Indeed, in my view the batch of the bike, rather than a design fault

The first days after the occurrence of this problem I felt myself deceived, like "7000$ " for a bike - and then something like this...
I'm sure this will be solved, maybe not now, but as several people have this common issue...
I guess Stromer has to take action and solve this.
But: Without this problem, my ST2 is a dream bike

And now the big question - how to locate this problem and how to solve?
I hope we can solve this out - and read more on this thread
ps: I also wonder if their is nothing about the torque sensor/ or recup logic/electronic ?? big questions

Regards

 

[bluecat]

And now the big question - how to locate this problem and how to solve?

OK, it seems, it's not that (well known) kind of pulsing which 86 and still kicking describes.

How are the settings for the strength of the motor brake (left brake handle)?

Set this value to zero, then only use the left brake handle whilst waiting on red signs.

 

[Berlin]

OK, it seems, it's not that (well known) kind of pulsing which 86 and still kicking describes.

How are the settings for the strength of the motor brake (left brake handle)?

Set this value to zero, then only use the left brake handle whilst waiting on red signs.

@bluecat
Indeed quot: " it seems, it's not that (well known) kind of pulsing"
The motor assistance cut off and on (you can fell it and see it on the display)
As well described above in the thread.

For the moment my ST2 is in maintenance at the shop - they are going to change the rear brake sensor...
in response to this problem.

I have a question, with the left handle - you mean the front brake?
I did not know that the brake sensors were individual adjustable.
Can you select left and right on the display?

After my vacation - within 2 weeks (and I have my bike back) I will modify the sensor settings.
Unless I read in this tread anything else
Thx & regards

 

[Mitchell Waite]

My dealer contacted Stromer about the pulsing and this is what they said:

Stromer: This is normal. Because of the power of the ST2, which far surpasses the Turbo, especially in mode 3 (max torque and speed), it is really noticeable when the assist cuts out.

You can lessen this effect by reducing the “agility” setting via the cell phone app. “Agility” is how quick the motor engages or disengages when you start to pedal or stop. A high agility setting will lead to a “pulsing” feel because the motor kicks in instantly when you start pedaling, and cuts out instantly when you stop pedaling. A lower agility setting increases the amount of time between pedaling and motor engagement/disengagement. This leads to a smoother ride. My personal preference is a low agility setting with max torque and max speed. Keep in mind that when you apply these settings via the phone app, Mode 2 is your custom tuned setting.

They claim this pulsing is normal, and it can be reduced [but not eliminated?] via the iPhone app by setting the "Agility" to low. This will affect mode 2 (not 3).

Personally if this really works, I find it an unsatisfactory solution because a) it sounds like you end up with having to use the lower power mode 2 to lower the pulsing and that makes me think you will still feel it in the higher power mode 3, which I prefer to use since its where all the ST2 power is.

Can someone with an ST2 try this and lets us know if it helps?

 

[Mitchell Waite]

People posing in this topic:

Please see the Poll I put together at the start of this thread and vote if your have this problem of pulsing or not.

 

[Rick Huizinga]

#5 ain't much help either, as st2 shuts off at 28, not 20

In power level 1, the speed cutoff on the ST2 is roughly 20mph. When biking in power level 1, I frequently travel near the speed cutoff, and it is definitely noticeable. This isn't a defect, just normal operation of the bike when pedaling aggressively for fitness purposes and hitting the speed limiter.

 

[Mitchell Waite]

In power level 1, the speed cutoff on the ST2 is roughly 20mph. When biking in power level 1, I frequently travel near the speed cutoff, and it is definitely noticeable. This isn't a defect, just normal operation of the bike when pedaling aggressively for fitness purposes and hitting the speed limiter.

I don't notice the pulsing as much in Assist Mode 1 as I do in Mode 3. Which makes sense because Mode 3 is when the most amount of power is being applied to the motor. I also don't notice it as much at low speeds in any of the 3 modes.

This whole "its normal" business is beginning to sound like a coverup for a real problem.

 

[Rick Huizinga]

I don't think there is any kind of cover-up. This thread has described a bunch of different observations all loosely linked to the overall pulsing sensation. If there is a real problem, denial may be a more appropriate description than cover-up.

Power level 3 long duration pulsing is normal. It quickly provides a large amount of power that is unexpected, and the rider responds by easing off the pedal resulting in an immediate power drop-off.

The shorter duration stuttering that I've experienced seems to be related to hitting the level 1 speed limiter after a long ride, and coming off power level 2. It's most likely myself being accustomed to a fast ride (at power level 2), then switching to power level 1 and bumping up against the power limiter after being tired from a long ride.

Note: post edited for typing errors.

 

[fxr3]

Maybe you are bumping up against the "speed limiter"
Is it only happening at 27+ mph? I did not know assist level one limits cutoff at 20mph. If I could continually bump 20 in level assist one-I'd be thrilled with my conditioning, and I'll have to try that.
In fact, I'm gonna go try it right now.

 

[fxr3]

If you are bumping against the 28mph shutoff- then, speaking for myself, this thread has been a serious waste of my time.

 

[Rick Huizinga]

I've also experienced what I believe is a thermal protection power cut-off. In short: hot day, long steep climb. After the climb, power was intermittently provided until after I took action to reduce heat in the motor. I.e. dropping to power level 1, and taking it easy for a mile or so.

 

[fxr3]

A"cover-up"? You and/ or your dealer aren't even listening to what Stromer is saying....."when the assist cuts out"! Assist cuts out when you stop pedaling or reach 28mph. If it's doing it at any other time- there is a problem with YOUR bike. The agility setting only makes it happen a second later.
They are also correct turbo bike doesn't do it, cause it does not have near the assist power the stromer has.
My st1 doesn't have noticable drag when I stop pedaling and coast- for the same reason.

 

[Mitchell Waite]

Maybe you are bumping up against the "speed limiter"
Is it only happening at 27+ mph? I did not know assist level one limits cutoff at 20mph. If I could continually bump 20 in level assist one-I'd be thrilled with my conditioning, and I'll have to try that.
In fact, I'm gonna go try it right now.

Its not the speed limiter as the cut out happens when peddling at 10 to 20 mph with 15 to 17 mph being the most obvious.

 

[Mitchell Waite]

A"cover-up"? You and/ or your dealer aren't even listening to what Stromer is saying....."when the assist cuts out"! Assist cuts out when you stop pedaling or reach 28mph. If it's doing it at any other time- there is a problem with YOUR bike.

We are listening but maybe your not reading all the posts? The problem happens for me, and apparently for many others, when peddling at a steady rate, steady pressure. When we coast I can feel the engine cutting out. That is NOT what we are referring to in these posts as pulsing because when the engine cuts out it stays cut out. The cutting out is an annoyance I can live with.

The agility setting only makes it happen a second later.
They are also correct turbo bike doesn't do it, cause it does not have near the assist power the stromer has.
My st1 doesn't have noticeable drag when I stop pedaling and coast- for the same reason.

I really don't think you can blame the higher assist power of the ST2 because if that were the case you'd still feel the pulsing at the lower power levels, just not as pronounced.

 

[Mitchell Waite]

I've also experienced what I believe is a thermal protection power cut-off. In short: hot day, long steep climb. After the climb, power was intermittently provided until after I took action to reduce heat in the motor. I.e. dropping to power level 1, and taking it easy for a mile or so.

Do you understand you are speculating yet another theory here of the cause of the periodic pulsing/stuttering/cut out. I'll add it to the growing list.

 

[Mitchell Waite]

Article on torque sensors is pretty interesting. But Stromer in picture is 2 generations old( at least 3 years, I'm guessing). If you ever get to Ventura, you can ride both of mine. I am truly altruistic when it comes to stromer bikes and their customers! Barry 8056250223

Your right about that, so I replaced it with a few articles that are more recent and more informative.

 

[John ware]

Hey All,

I've recently joined the list and have had my ST2 for just about a month now. It was a media loaner bike with 300 miles on it and I have put around another 300 of my own miles on it. Mainly late evening rides around town.

I've been following the pulse discussion closely. I have to say after this evenings ride and intense scrutiny, that I can not replicate the problem Mitchell is describing. My overall torque sensory setting is at 75%, I'm big guy and I experimented on long gradual slopes at 12-18 mph as well as dead flat smooth roads at 20-25 mph all in the #3 mode. Outside temperature was 61.

My guess is something is wrong with your machine and you need to take it into your dealer and strongly suggest they consider some warranty work at this point. They should be able to reproduce the problem with a test ride. One thing is certain these bikes are a sophisticated mixture of sensors, batteries, electric motors, switches, wiring, software and on board computers, combined with a bunch mechanical parts. To suggest they are all properly aligned on each of our bikes is a tall claim, even for the Swiss.

All that said I'm still picking the bugs out of my giant grin every time I come back from a ride. Thanks to everyone for contributing to this list and sharing their adventures, upgrade and tips.

John

 

[Mitchell Waite]

Hey All,

I've recently joined the list and have had my ST2 for just about a month now. It was a media loaner bike with 300 miles on it and I have put around another 300 of my own miles on it. Mainly late evening rides around town.

I've been following the pulse discussion closely. I have to say after this evenings ride and intense scrutiny, that I can not replicate the problem Mitchell is describing. My guess is something is wrong with your machine and you need to take it into your dealer and strongly suggest they consider some warranty work at this point. They should be able to reproduce the problem with a test ride.
John

John thanks for your comments. You may be right that this is a problem with the bikes at this dealer and not indicative of the product line. I have not purchased a STW but rather have been test riding it and based on this issue of pulsing trying to decide if I want to buy it. The dealer has ridden with me and recognize the publishing is excessive and has notified Stromer of the problem. Stromer claims that pulsing is normal and due to the power surpassing that of the Specialized Turbo. He says you can lessen the effect by reducing the agility setting via the iPhone app and this will affect only mode 2. Here is his exact comment:

"Response from the Stromer representative: This is normal. Because of the power of the ST2, which far surpasses the Turbo, especially in mode 3 (max torque and speed), it is really noticeable when the assist cuts out.

You can lessen this effect by reducing the “agility” setting via the cell phone app. “Agility” is how quick the motor engages or disengages when you start to pedal or stop. A high agility setting will lead to a “pulsing” feel because the motor kicks in instantly when you start pedaling, and cuts out instantly when you stop pedaling. A lower agility setting increases the amount of time between pedaling and motor engagement/disengagement. This leads to a smoother ride. My personal preference is a low agility setting with max torque and max speed. Keep in mind that when you apply these settings via the phone app, Mode 2 is your custom tuned setting."

My dealer told me they need Stromer's permission to change this setting and we are waiting to get there okay. The reason for this is the dealer can't register and pair an iPhone with a bike unless the bike has been sold. (Personally this seems dumb since how is a customer to fully test the bike if a component as important and well integrated as the smartphone app can't be tested?) The dealer wants to register the app, let us test it, and then unregister it. If Stromer says no then I will be unable to determine if this agility setting really solves the problem. And without knowing that I won't be spending $7,000 on what, as you point out, may be a flaw in this particular batch of bikes.

 

[John ware]

Well, I guess the good news is you have not dropped a chunk of change on a faulty machine. Bad news is this issue is keeping you from falling in love with a ST2. Any chance they have another bike for you to bond with?

John

 

[Mitchell Waite]

Well, I guess the good news is you have not dropped a chunk of change on a faulty machine. Bad news is this issue is keeping you from falling in love with a ST2. Any chance they have another bike for you to bond with?

John

Today my salesperson said they made the modification to the Agility setting with the app and the pulsing has almost disappeared. I'll ride it tomorrow and report back. Its pretty incredible it's taken all this work and time to get the dealer to even recognize there is a problem.