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[sharkimano]

If you press reset in the custom screen for that speed setting, e.g Emtb+ etc it’ll show 20mph. It did this before the mod as well ( reported 1mph less)

Thank you for the tip. However I did that, reset at the custom screen but it still shows 19mph in imperial units and 32kph in metric screen.. It really sucks that support is cut off at 30km/h. I don't know what else I can do to get around this annoying issue.

 

[mcmcmc]

For anyone who switched from an EU setting to US, have you had any success changing the wheel circumference to draw out any extra speed? I could only make relatively small adjustments through the Flow app for my Cube, certainly nothing that would let me get to about 45km/h real-world speed. Was that a different setting/process?

I'm pretty happy with the 32km/h, I've done about 250km since it was done, issue-free but as others point out the drop-off in assist is quite obvious. I know it's mad. I feel a bit like Goldilocks trying to get the best of all worlds...

FWIW, my update was done by the now-departed Rudie, if that makes a difference.

 

[Joecrow]

I could only make relatively small adjustments through the Flow app for my Cube, certainly nothing that would let me get to about 45km/h real-world speed. Was that a different setting/process?

I strongly suspect that changing the wheel circumference enough to produce a significant speed increase would require a further configuration change, i.e. something that our absent friend Rudi or the E-bike doctor would need to be do via the Bosch Diagnostic port. I have not tried to change it via the Flow app on my bike but I suspect Bosch only allows minor changes to compensate for different tyre types.

 

[TheKaiser]

For anyone who switched from an EU setting to US, have you had any success changing the wheel circumference to draw out any extra speed? I could only make relatively small adjustments through the Flow app for my Cube, certainly nothing that would let me get to about 45km/h real-world speed. Was that a different setting/process?

I'm pretty happy with the 32km/h, I've done about 250km since it was done, issue-free but as others point out the drop-off in assist is quite obvious. I know it's mad. I feel a bit like Goldilocks trying to get the best of all worlds...

FWIW, my update was done by the now-departed Rudie, if that makes a difference.

As @Joecrow mentioned, my understanding is that the user level adjustments for wheel size will change/correct your display speed, but weirdly they do not change the assistance cutoff. So in other words, if your bike is cutting out at a display speed AND actual speed of 19mph, and you change the wheel size to a smaller one, the bike may now cut out at a display speed of 20mph BUT it will still actually be the same 19mph actual speed as before. I know that sounds weird, but that is what the reading I did indicated. To put it another way, the motor settings are separate from the display readout settings, and the wheel size menu you have access to only alters the display settings.

In order to actually get more speed out of it, you need to do as Joe mentioned and have one of the "Rudie type" guys alter the wheel size in the deeper level container file. The most common way of doing that is by putting in a wheelsize that is 1/2 of actual, for the simple reason that it makes it easier to calculate your actual speed and distance in your head, although it will give you far more speed than you're actually asking for.

 

[rearwheelcircumference]

As @Joecrow mentioned, my understanding is that the user level adjustments for wheel size will change/correct your display speed, but weirdly they do not change the assistance cutoff. So in other words, if your bike is cutting out at a display speed AND actual speed of 19mph, and you change the wheel size to a smaller one, the bike may now cut out at a display speed of 20mph BUT it will still actually be the same 19mph actual speed as before. I know that sounds weird, but that is what the reading I did indicated. To put it another way, the motor settings are separate from the display readout settings, and the wheel size menu you have access to only alters the display settings.

In order to actually get more speed out of it, you need to do as Joe mentioned and have one of the "Rudie type" guys alter the wheel size in the deeper level container file. The most common way of doing that is by putting in a wheelsize that is 1/2 of actual, for the simple reason that it makes it easier to calculate your actual speed and distance in your head, although it will give you far more speed than you're actually asking for.

I confirm. Changing the wheel size is only possible with Bosch software, via container files.
Now, I perfectly know my multiplication table for two.

 

[sharkimano]

As @Joecrow mentioned, my understanding is that the user level adjustments for wheel size will change/correct your display speed, but weirdly they do not change the assistance cutoff. So in other words, if your bike is cutting out at a display speed AND actual speed of 19mph, and you change the wheel size to a smaller one, the bike may now cut out at a display speed of 20mph BUT it will still actually be the same 19mph actual speed as before. I know that sounds weird, but that is what the reading I did indicated. To put it another way, the motor settings are separate from the display readout settings, and the wheel size menu you have access to only alters the display settings.

In order to actually get more speed out of it, you need to do as Joe mentioned and have one of the "Rudie type" guys alter the wheel size in the deeper level container file. The most common way of doing that is by putting in a wheelsize that is 1/2 of actual, for the simple reason that it makes it easier to calculate your actual speed and distance in your head, although it will give you far more speed than you're actually asking for.

I have 29" Wheels. By this I get: 29 x 25.4 x 3.141592=2314mm Wheel Size. However since there is few inches of Tire Thickness the actual circumference is bigger than 2314mm. So this results in under-reporting speed on the display by the motor. In my case I could reduce to Wheel size to the Minimum of 2185mm which is roughly 27.38" inch wheel size. At this setting the speed reported by Flow app matches the speed I measured by another app (GPS speedometer). Nevertheless the motor still cuts off support around 29-30km/h in the USA setting. If I set units to Imperial the max speed I can customize is 19mph. In Metric I can set it to 32km which corresponds to 19.87mph, not quite 20mph which was the agreed standard for USA. So I am really frustrated about this even though it's not much of a difference but the inconsistency is odd to say the least.

 

[Mario Antony]

I have 29" Wheels. By this I get: 29 x 25.4 x 3.141592=2314mm Wheel Size. However since there is few inches of Tire Thickness the actual circumference is bigger than 2314mm. So this results in under-reporting speed on the display by the motor. In my case I could reduce to Wheel size to the Minimum of 2185mm which is roughly 27.38" inch wheel size. At this setting the speed reported by Flow app matches the speed I measured by another app (GPS speedometer). Nevertheless the motor still cuts off support around 29-30km/h in the USA setting. If I set units to Imperial the max speed I can customize is 19mph. In Metric I can set it to 32km which corresponds to 19.87mph, not quite 20mph which was the agreed standard for USA. So I am really frustrated about this even though it's not much of a difference but the inconsistency is odd to say the least.

That was the reason why I choosed Rudi and 64km/h deresctrition.
I have no restrictions on speed, and bike feel as a bike. You push the pedals, and it will respond, without the "drop the anchor effect" that I had once reached 25km/h.

For those that think, by changing the software to 64km/h, you'll be a motorcycle, I'm afraid you'll be disapointed.
You still need to push the pedals, and speed will be limited by your final drive.

Personally, I set my speed limit @30km/h to connect to trails (public road), because once you reached 30km/h, you'll be on the threshold of motor assist, and motor will turn on/off and save your battery for TRAIL riding.

If the rider maintains a high assistance (and speed of course) - like going 40km/h, battery consumption will be very high, and once reaching the trails, you won't have too much range.

Highest speed I could attain, on flat road, pushing the pedals and drafting & racing a triathlon attlet was 46km/h (I have 34x11 ~ 120rpm).
Theoretically, I could go up to 58km/h, being able to spin at 150rpm... but I won't spin that fast on open public road, because it's not safe.

 

[Joecrow]

I have 29" Wheels. By this I get: 29 x 25.4 x 3.141592=2314mm Wheel Size. However since there is few inches of Tire Thickness the actual circumference is bigger than 2314mm. So this results in under-reporting speed on the display by the motor. In my case I could reduce to Wheel size to the Minimum of 2185mm which is roughly 27.38" inch wheel size. At this setting the speed reported by Flow app matches the speed I measured by another app (GPS speedometer).

I'm not sure I understand you on this! If you saying that with your 29" wheels your original circumference setting was 2314, that for me seems to be about right, (bear in mind the dia. of a 29" wheel is 622mm plus about 115mm of tire so 737 x 3.142 = 2315), then the display speed should be accurate not under reported! Reducing the circumference setting down to 2185 should result in the display speed under reporting by approximately 1.8 kmh at an actual speed of 32kmh. I have no idea though if the motor assist would continue to an actual 33.92 kmh (32kmh displayed) or not???

 

[sharkimano]

I'm not sure I understand you on this! If you saying that with your 29" wheels your original circumference setting was 2314, that for me seems to be about right, (bear in mind the dia. of a 29" wheel is 622mm plus about 115mm of tire so 737 x 3.142 = 2315), then the display speed should be accurate not under reported! Reducing the circumference setting down to 2185 should result in the display speed under reporting by approximately 1.8 kmh at an actual speed of 32kmh. I have no idea though if the motor assist would continue to an actual 33.92 kmh (32kmh displayed) or not???

You are correct. I think I meant to say it Over reported speed not under. Reducing wheel size should also reduce apparent speed reported Wheel diameter (29" for instance) gives you 2314mm circumference but setting this in the settings somehow does not give correct speed when measured by Phone GPS. I am sure there are dependencies in GPS measurements too but all I know when I set Wheel size to 2185 I get about same speed by Phone GPS. So the question is who is right... Phone GPS or Bosch ?

 

[Joecrow]

I have no idea though if the motor assist would continue to an actual 33.92 kmh (32kmh displayed) or not???

To answer my own question I took a test ride and with the wheel circumference set to original 2135mm for my 27.5" wheel, the motor assist declined noticeably, as expected, at around 31kmh. I then set the circumference to its lowest size 2028mm a reduction of approx. 5% I then tried again but this time the motor assist faded out at a the display speed of around 29kmh (actual 31 kmh).
So on that basis I conclude that the minor adjustment of the wheel circumference available via the Flow app. is only to calibrate the display speed, in the event for example of fitting different tires, and has no impact on the real speed where the motor assist cuts out.

I am sure there are dependencies in GPS measurements too but all I know when I set Wheel size to 2185 I get about same speed by Phone GPS. So the question is who is right... Phone GPS or Bosch ?

Good question, I have no way of knowing or comparing whether the display speed with the correct wheel circumference is the true speed. In your case with the reduced wheel size and the display and GPS speeds matching, what is the display speed where the motor assist fades out?

 

[sharkimano]

To answer my own question I took a test ride and with the wheel circumference set to original 2135mm for my 27.5" wheel, the motor assist declined noticeably, as expected, at around 31kmh. I then set the circumference to its lowest size 2028mm a reduction of approx. 5% I then tried again but this time the motor assist faded out at a the display speed of around 29kmh (actual 31 kmh).

I find this odd. So setting to a bigger "Wheel" value gives you more support at higher speed ! This is counterintuitive since motor firmware is using the wheel value to deduct speed. (RPM x Wheel=Speed) and the display should match what the Firmware is measuring but in your case the speed is being cut off at a lower speed. ?! This means if I set the wheel to a higher value (in my case max is 2415 which corresponds to 30+ inches) I should get a higher cut off speed, right ? I am eager to try this tomorrow to see the result. I would be extremely happy if I could squeeze few more km/h out of this Bosch engine

So on that basis I conclude that the minor adjustment of the wheel circumference available via the Flow app. is only to calibrate the display speed, in the event for example of fitting different tires, and has no impact on the real speed where the motor assist cuts out.

Good question, I have no way of knowing or comparing whether the display speed with the correct wheel circumference is the true speed. In your case with the reduced wheel size and the display and GPS speeds matching, what is the display speed where the motor assist fades out?

 

[Joecrow]

I find this odd. So setting to a bigger "Wheel" value gives you more support at higher speed ! This is counterintuitive since motor firmware is using the wheel value to deduct speed. (RPM x Wheel=Speed) and the display should match what the Firmware is measuring but in your case the speed is being cut off at a lower speed. ?! This means if I set the wheel to a higher value (in my case max is 2415 which corresponds to 30+ inches) I should get a higher cut off speed, right ? I am eager to try this tomorrow to see the result. I would be extremely happy if I could squeeze few more km/h out of this Bosch engine

No, No, what I'm saying, based on my test ride, is that the only thing that changes by adjusting the wheel circumference setting in the Flow app. is the display speed not the actual speed that drives the motor assist. I assume the motor is detecting the speed based on the wheel circumference loaded in the configuration not the setting in the Flow app. So regardless of what changes are made in the Flow app. the motor assist will stubbornly continue to cut out at 32 kmh regardless of what figure is shown in the display!
If you change your wheel circumference setting to a higher value in the Flow app. it may appear the motor assist cutoff speed is higher but that is because the display will be lying to you, the actual cut off speed will be unchanged.
If you fitted an actual bigger wheel then yes the motor would cut out at a higher speed.

 

[sharkimano]

No, No, what I'm saying, based on my test ride, is that the only thing that changes by adjusting the wheel circumference setting in the Flow app. is the display speed not the actual speed that drives the motor assist. I assume the motor is detecting the speed based on the wheel circumference loaded in the configuration not the setting in the Flow app.

Ok but who sets the wheel circumference in configuration ? I assumed it was done in Flow app and that the motor derives the speed based on what is set in Flow app. Otherwise what is the use of setting it in Flow app? It detects the wheel rotation from the microswitch and the magnet on wheel. (one bleep every rotation) It then calculates it according to Speed=RPM x Wheel Circumference. I dont believe the motor has the ability to detect speed independently (Unless it has a built-in GPS !) All the chips like SpeedBox etc fool the motor by interrupting the microswitch signal and feeding a different RPM to the FW of the motor...This is why I was confused when you said the cut off speed displayed was different for different wheel sizes. Correct me if I am wrong about this assumption....

 

[Jackware]

@Shark58
Can you clarify this please

 

[Joecrow]

Ok but who sets the wheel circumference in configuration ?

Normally the bike manufacturer but it can also be changed e.g. halved to de-restrict the bike which will effectively double the speed at which the motor assist cuts out but as will result in the display only showing half the actual speed.

Otherwise what is the use of setting it in Flow app?

I think it is merely a minor separate adjustment to allow the display to accurately show the speed to compensate if different tires are fitted.

I dont believe the motor has the ability to detect speed independently

I think it does, nothing to do with GPS, it simply calculates the speed based on the circumference in the configuration and the number of pulses from the speed sensor. half the wheel circumference in the configuration or half the pulses from the speed sensor (speed box), both will double the real speed.

 

[Raptor]

Is it a coincidence that both Rudy (Rudolph/Rudi or whatever) and Altrui (Ebike-doctor) have both disappeared from this forum?

 

[sharkimano]

Normally the bike manufacturer but it can also be changed e.g. halved to de-restrict the bike which will effectively double the speed at which the motor assist cuts out but as will result in the display only showing half the actual speed.

I think it is merely a minor separate adjustment to allow the display to accurately show the speed to compensate if different tires are fitted.

I think it does, nothing to do with GPS, it simply calculates the speed based on the circumference in the configuration and the number of pulses from the speed sensor. half the wheel circumference in the configuration or half the pulses from the speed sensor (speed box), both will double the real speed.

Assuming the wheel size is set in the configuration in the FW, if the person decides to use a different wheel size then the spec limit set by law (20mph USA, 25kph Europe) has no meaning. Furthermore they will have to adjust the firmware for every brand since every company uses different wheel sizes. I don't know what Bosch actually does but in my opinion this is a very bad design choice. Showing a speed on the display different than the actual speed is borderline fraudulent. Imagine a car speedometer showing wrong speed. Lawyers would get in line to sue that company
Any way enough rambling on my part.

 

[Mario Antony]

When you adjust wheel circunferance in flow app, you will change speed limit.
It's not much, like ~1Km/h.
Bosch allows this, so that riders can adjust their motor to tire change. Eg: a 2.4x27.5 has a smaller diameter then a 2.6x27.5 or even 2.8x27.5 (same brand, since this can vary from brand to brand).

Anyone can verify this using a GPS.

 

[Joecrow]

Assuming the wheel size is set in the configuration in the FW, if the person decides to use a different wheel size then the spec limit set by law (20mph USA, 25kph Europe) has no meaning.

If you change to a wheel size that increased the the assist speed above the legal limit (20mph USA, 25kph Europe) then you would be breaking the law.

Furthermore they will have to adjust the firmware for every brand since every company uses different wheel sizes.

But that is exactly what they do, every bike model and brand have their differences which is why the firmware configuration is provided from the bike manufacturer not Bosch. It is not just the wheel sizes it can be whether the lighting and other power ports are activated and if the frame water bottle fixing can support the PowerMore range extender and a host of other things I suspect!

Showing a speed on the display different than the actual speed is borderline fraudulent. Imagine a car speedometer showing wrong speed.

If there are no changes to the setup then the speedo should be accurate. If you deliberately change the wheel circumference setting to a false value then that's not Bosch's responsibility but it would be a problem for them if doing so allowed you to exceed the legal speed limit for the motor assist, which is why I believe it doesn't.

When you adjust wheel circunferance in flow app, you will change speed limit.
It's not much, like ~1Km/h.
Bosch allows this, so that riders can adjust their motor to tire change. Eg: a 2.4x27.5 has a smaller diameter then a 2.6x27.5 or even 2.8x27.5 (same brand, since this can vary from brand to brand).

Anyone can verify this using a GPS.

Changing the tire brand or size, as you suggest, to one with a bigger circumference will indeed marginally increase the speed at which the motor assist cuts out but I do not believe just changing the setting in the Flow app. alone will do anything other than display the incorrect speed. I believe the Flow app. circumference setting is there to allow us match the display speed accurately if the rear tire is replaced with one of a slightly different size.

 

[sharkimano]

If you change to a wheel size that increased the the assist speed above the legal limit (20mph USA, 25kph Europe) then you would be breaking the law.

But that is exactly what they do, every bike model and brand have their differences which is why the firmware configuration is provided from the bike manufacturer not Bosch. It is not just the wheel sizes it can be whether the lighting and other power ports are activated and if the frame water bottle fixing can support the PowerMore range extender and a host of other things I suspect!

If there are no changes to the setup then the speedo should be accurate. If you deliberately change the wheel circumference setting to a false value then that's not Bosch's responsibility but it would be a problem for them if doing so allowed you to exceed the legal speed limit for the motor assist, which is why I believe it doesn't.


Changing the tire brand or size, as you suggest, to one with a bigger circumference will indeed marginally increase the speed at which the motor assist cuts out but I do not believe just changing the setting in the Flow app. alone will do anything other than display the incorrect speed. I believe the Flow app. circumference setting is there to allow us match the display speed accurately if the rear tire is replaced with one of a slightly different size.

Okay I see what you are saying and may be it is exactly how you describe it. However, since I come from a Computer Field where I spent a good 25 years of my career, I find it really odd that a specific parameter (Wheel Size !) is totally ignored by the firmware and assumed to be different than it actually is to adjust motor support. For example: This is akin to MS Windows making an assumption about Display Graphic Memory size and ignoring what is actually installed in the system. That is why we have graphic drivers that tells the Windows Kernel and BIOS how much memory it has so that it could use the full potential of that memory. But I digress may be Bosch was concerned that people would abuse this by changing wheel size to get around the speed limit set by law. In the meantime those of us who put in the correct wheel size are penalized too !.
Cheers

 

[Suke]

Is it a coincidence that both Rudy (Rudolph/Rudi or whatever) and Altrui (Ebike-doctor) have both disappeared from this forum?

What? Ebike-doctor too?

 

[Joecrow]

What? Ebike-doctor too?

The website is still online, maybe Altui is just keeping a low profile.

 

[Raptor]

The website is still online, maybe Altui is just keeping a low profile.

His profile on here has been deleted and his website is a lot low key compared to previous

 

[Suke]

Bosch is definitely pushing

 

[martyfrommonmouth]

His profile on here has been deleted and his website is a lot low key compared to previous

I should imagine the threat of being sued by a large multi billion corporation will do that.

 

[Raptor]

I should imagine the threat of being sued by a large multi billion corporation will do that.

exactly! Rudie/Rudolph whatever his name is has disappeared more times than Houdini!

 

[rearwheelcircumference]

Ok but who sets the wheel circumference in configuration ? I assumed it was done in Flow app and that the motor derives the speed based on what is set in Flow app. Otherwise what is the use of setting it in Flow app? It detects the wheel rotation from the microswitch and the magnet on wheel. (one bleep every rotation) It then calculates it according to Speed=RPM x Wheel Circumference. I dont believe the motor has the ability to detect speed independently (Unless it has a built-in GPS !) All the chips like SpeedBox etc fool the motor by interrupting the microswitch signal and feeding a different RPM to the FW of the motor...This is why I was confused when you said the cut off speed displayed was different for different wheel sizes. Correct me if I am wrong about this assumption....

Actually, there are two different wheel circumference parameters:

• A firmware parameter set by the manufacturer: The power assistance speed limit is calculated based on this parameter.
• A firmware parameter adjustable by the bike owner (via the Flow app): This parameter is used to display the speed on the screen, allowing for minor corrections depending on the tires mounted on the bike. The motor assistance cut-off is not affected by this setting.

 

[Suke]

Actually, there are two different wheel circumference parameters:

• A firmware parameter set by the manufacturer: The power assistance speed limit is calculated based on this parameter.
• A firmware parameter adjustable by the bike owner (via the Flow app): This parameter is used to display the speed on the screen, allowing for minor corrections depending on the tires mounted on the bike. The motor assistance cut-off is not affected by this setting.

Yop the flow app settings doesn't affect the real max speed. I tested it via GPS speed app with min/max wheel circ. settings.

 

[Joecrow]

Bosch is definitely pushing

Big Brother Bosch is watching us!

 

[Mario Antony]

If you change to a wheel size that increased the the assist speed above the legal limit (20mph USA, 25kph Europe) then you would be breaking the law.

But that is exactly what they do, every bike model and brand have their differences which is why the firmware configuration is provided from the bike manufacturer not Bosch. It is not just the wheel sizes it can be whether the lighting and other power ports are activated and if the frame water bottle fixing can support the PowerMore range extender and a host of other things I suspect!

If there are no changes to the setup then the speedo should be accurate. If you deliberately change the wheel circumference setting to a false value then that's not Bosch's responsibility but it would be a problem for them if doing so allowed you to exceed the legal speed limit for the motor assist, which is why I believe it doesn't.


Changing the tire brand or size, as you suggest, to one with a bigger circumference will indeed marginally increase the speed at which the motor assist cuts out but I do not believe just changing the setting in the Flow app. alone will do anything other than display the incorrect speed. I believe the Flow app. circumference setting is there to allow us match the display speed accurately if the rear tire is replaced with one of a slightly different size.

It's not a belief.

If you change the diameter on flow app, you'll change the speed limit (~1km/h).