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    Riding a tuned or deristricted EMTB is not a trivial offence and can have serious legal consequences. Also, many manufacturers can detect the use of a tuning device or deristricting method and may decline a repair under warranty if it was modified from the intended original specification. Deristricting EMTB's can also add increased loads for motors and batteries. Riding above the local law limit may reclassify the bike as a low-powered bike, requiring insurance, registration and a number plate.

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Jackware said:
@Shark58
Can you clarify this please
Click to expand...
I couldn't have explained it any better than this:
rearwheelcircumference said:
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.
Click to expand...
The user adjustable wheel circumference parameter can be changed by +-5% from its original value and only corrects the displayed speed.

When you ask your LBS for a diagnostic report from the Bosch diagnostic system you can see the two values. On bikes where the owner hasn't changed the user parameter both values are identical. As I always do with any new rear tire I measured the circumference on my Vala with a 27.5" rear wheel riding in a straight line for about 25 meters on even ground, measuring the covered distance and dividing that through the number of wheel rotations. After changing the parameter via the Flow app my diagnostic report shows (I only have a German report, the higher value is the factory one, the lower value is the corrected one):
Vala Radumfang.webp
 
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To go even further with the explanation using Shark58's case:

With a wheel that has a physical circumference of 2072 mm, the motor assistance will cut off a bit earlier. This is because the algorithm continues to use the 2130 mm circumference as its reference point.

If you want the motor assistance to cut off at twice the speed without changing the factory settings, you would physically need to fit a wheel with a 4260 mm circumference! 😁
 
Last edited:
Mario Antony said:
It's not a belief.

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

Believe what you like but I am not alone in saying it doesn't!
rearwheelcircumference said:
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.
Click to expand...
Suke said:
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.
Click to expand...
Shark58 said:
The user adjustable wheel circumference parameter can be changed by +-5% from its original value and only corrects the displayed speed.
Click to expand...
 
rearwheelcircumference said:
With a wheel that has a physical circumference of 2072 mm, the motor assistance will cut off a bit earlier. This is because the algorithm continues to use the 2130 mm circumference as its reference point.
Click to expand...
That is correct, but with my Vala I'm lucky. Even with the slightly to large factory value of 2130 mm the motor cuts off at a corrected displayed speed of 25.6 kph. 👍
 
Rudie said:
Bosch USA Software New Update ALL EBIKES LOCKED

Watch out
Click to expand...
Yeah but if you want you can derestrict your e bike however it will void any warranty and if you install the right one you can switch it off allowing updates but you'll need to check beforehand if the update will affect your chip. My bike is out of warranty so it's a no brainer however I do ride responsibly and will switch it on when on a clear stretch of trail. There's pros and cons yes it's illegal but I've never been stopped for speeding
 
Shark58 said:
I couldn't have explained it any better than this:

The user adjustable wheel circumference parameter can be changed by +-5% from its original value and only corrects the displayed speed.
Click to expand...
In my case My wheel parameter is set for 2300mm which is roughly 29" tire. My bike set for USA standard 32km and yet I can hardly get support at 29km ! I could live with cut off @31km but 29 ? That is malevolent on the part of Bosch !
 
Steve0101 said:
Yeah but if you want you can derestrict your e bike however it will void any warranty and if you install the right one you can switch it off allowing updates but you'll need to check beforehand if the update will affect your chip. My bike is out of warranty so it's a no brainer however I do ride responsibly and will switch it on when on a clear stretch of trail. There's pros and cons yes it's illegal but I've never been stopped for speeding
Click to expand...
What speed change did you get 32 KPH , did you get your wheel size changed , thinking of getting my Gen 4 done , out of warranty now , mullet set up with a 27.5 rear ?
 
Steve0101 said:
Yeah but if you want you can derestrict your e bike however it will void any warranty and if you install the right one you can switch it off allowing updates but you'll need to check beforehand if the update will affect your chip. My bike is out of warranty so it's a no brainer however I do ride responsibly and will switch it on when on a clear stretch of trail. There's pros and cons yes it's illegal but I've never been stopped for speeding
Click to expand...
45€ = Rudie Derestricted Flash - 5☆ service
+200€ = Chiptunning

It's a brainless choice, just saying!
 
mooby77 said:
What speed change did you get 32 KPH , did you get your wheel size changed , thinking of getting my Gen 4 done , out of warranty now , mullet set up with a 27.5 rear ?
Click to expand...
Had Rudi do mine today , 32 kph and change rear wheel dia to 50% of what it was 27.5 rear diameter originally

So if I understand correctly , per my settings at 25kph , I am getting 31 MPH , if I set to 32 kph i am getting circa 40 MPH which is too fast for me , so I have set max 25 Kph in Emtb+ and Turbo , and reduced my dynamic
down
All good
 
Rudie said:
Bosch USA Software Smart System 32KM/H 35 Euro

For all forum years 35 euro

Facebook name Rudolf Beukers or telegram @puntjesdaar

Got no whatsapp or phone number all other are fakers or expensive copycats

This is how it works:
You install teamviewer on computer(windows)!
You make sure you have a USB-C data cable to connect the bike to the computer.
I log in via the ID and password that teamviewer generates and make the change.

A lot of people dont use the tool and you can not see what happens to your bike here you see it.


We set your bike's speed settings to the USA standard.
This makes your bike 32 KM/H also visible in the flow app.
We can also let it go up to a maximum of 50 or 64 KM/H, but we then halve your wheel circumference, causing the bicycle to halve its speed on the display, for example (20kmh=10km).

The flow app and updates remain fully intact.
Before the update, you must ensure that your bike has the latest software via the flow app.

Everything is done with original Bosch diagnostic software.

If you later decide to change from 32 to 64, this is free of charge or vice versa.

View attachment 180754
Click to expand...
Does this RESET the error logs entered previously due to Chip tuning like SpeedBox ?
 
Hey guys. A I've rudies 64kph on my gen4 working perfectly.

But my friend has just put it on his gen5 after some errors with a speed box. Mid ride around 40% battery. His bike looses all its power. Changing modes doesn't help or make a difference. And no fault codes have came up

Has this happened to anyone else? I've suggested he removes the 64kph update and test the bike to see if it still does it.
 
rearwheelcircumference said:
To go even further with the explanation using Shark58's case:

With a wheel that has a physical circumference of 2072 mm, the motor assistance will cut off a bit earlier. This is because the algorithm continues to use the 2130 mm circumference as its reference point.

If you want the motor assistance to cut off at twice the speed without changing the factory settings, you would physically need to fit a wheel with a 4260 mm circumference! 😁
Click to expand...
Wrong ! you need to halve (divide by 2) the Circumference to go twice the speed. Half distance at same cadence Bosch FW will think you are going half speed than you actually are.
 
sharkimano said:
Wrong ! you need to halve (divide by 2) the Circumference to go twice the speed. Half distance at same cadence Bosch FW will think you are going half speed than you actually are.
Click to expand...
True, but in that case, you're modifying the factory settings!
To keep the factory settings, you'd need a wheel with twice the circumference.
 
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