• Warning!!

    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.

    Be aware of your local country laws. Many laws prohibit use of modified EMTB's. It is your responsibility to check local laws. Ignoring it, has potential implications to trail access, and risk of prosecution in the event of an accident.

    UK Pedelec Law

    Worldwide Laws

    We advise members great caution. EMTB Forums accepts no liability for any content or advice given here. 


Derestricting bosch smart system

Ashley3283

New Member
Jun 27, 2023
16
4
UK
Hi, I am interested in the megabobra approach, I have a Cube Stereo 160 which has the magnet on the brake disc. Can I put this solution between the existing magnet and sensor (e.g. have an additional sensor where the original one is, go through the Arduino then put out a reduced magnet read to the original sensor)? This would negate the need to cut my original wire and mess around with placing an electro magnet in the right place on the motor?

Or am I over simplifying things here? Not sure if the wheel sensor is just for the display or the wheel sensor need to match the motor sensor?

Thanks
 

megabobra

Active member
Jul 24, 2022
220
237
Australia
Hi, I am interested in the megabobra approach, I have a Cube Stereo 160 which has the magnet on the brake disc. Can I put this solution between the existing magnet and sensor (e.g. have an additional sensor where the original one is, go through the Arduino then put out a reduced magnet read to the original sensor)? This would negate the need to cut my original wire and mess around with placing an electro magnet in the right place on the motor?

Or am I over simplifying things here? Not sure if the wheel sensor is just for the display or the wheel sensor need to match the motor sensor?

Thanks
Hi Ashley,
Yes I believe that will work fine. We discussed this method a while back in this thread when someone else mentioned their existing disc sensor setup. Sadly though I don't have a bike with a disc sensor to test it on and I'm not sure the other guys in this thread ended up pursuing it.

The only thing to consider is the existing megabobra takes power from the green low power port (LPP) on the motor, which I believe is also used for the speed sensor? Again I can't confirm this one sorry - maybe take a look at your motor and check what ports are used/free? If that was the case, you would need to use perhaps the front or rear light port to power the megabobra. Downside of this is that when enabling the light ports, Bosch restrict motor usage when the battery gets below defined cutoff. This is set by the store from memory, but for example, it may be set to 10% whereby below that point, no motor power will be provided in order to instead converse battery power to run the lights. So ideally it's best to use the LPP to avoid this restriction.
 

megabobra

Active member
Jul 24, 2022
220
237
Australia
Thanks for all the posts and messages with interest in the megabobra. I've spent some time sourcing components that would be needed for this project and worked out some costing.

This would comprise all necessary components to install the megabobra to replace the rim magnet, including the genuine Bosch LPP cable to plug into the motor:
  • Arduino loaded with megabobra code and additional electronic components soldered in place
    • Covered with double-wall heat shrink for protection
  • Waterproof reed switch
  • Hand wound electromagnet coil
  • All wiring in place and secured
  • Light weight plugs between components to assist with install
  • Bosch LPP cable
  • Magnet for disc rotor
  • Some strips of double-sided tape for reed switch and coil
  • Short install guide to assist with connection/placement/troubleshooting
Total cost per device would be 99USD/80GBP/90EUR or equivalent in your favourite currency. This include shipping worldwide. Payment by Paypal.

Now to manage expectations, this isn't a commercial product. The finish isn't going to be as nice as you might get in a product off the shelf simply because I don't have access to the customisation that large scale affords. For example, where the big companies might have a reed switch with custom-length cable for the perfect fit, I'll instead need to extend that cable myself to make it work. However, all builds would be carefully assembled and tested prior to going out, and I'd be happy to replace any that are not working.

The idea with this is that you unpack the device, feed the reed switch through the frame, position the coil, plug in the LPP and get going ASAP - probably an hour's install on the first run giving it's pretty tight around the motor on some frames?

IMPORTANT
Running from the LPP on the motor requires that port to be activated. If it's not already activated, you'll need to have your local dealer enable it. That's done through the USBC connection on the smart controller on your bars.

There's no integration with the Kiox display, so the display will work as before though all metrics will be offset by the multiplier value you choose. I've been running my device on Bosch's latest firmware version, but critically, ensure you're not using GPS when running the device - I've got no confirmation on this, but I would expect detection if GPS speed doesn't agree with sensor reported speed.

Assuming there's still interest now that you know the pricing, please like/reply to this if you're happy to go ahead so I can understand numbers for the components I'll need to bring in. Time frame wise, it would probably be 4-6 weeks before I can get any devices out due to the lead time with these required components. Ordering just be through Private Message where you can specify the required multiplier and wheel circumferance for your setup.

Thanks all.
 

timothe

New Member
Jun 2, 2023
19
9
UK
Thanks for all the posts and messages with interest in the megabobra. I've spent some time sourcing components that would be needed for this project and worked out some costing.

This would comprise all necessary components to install the megabobra to replace the rim magnet, including the genuine Bosch LPP cable to plug into the motor:
  • Arduino loaded with megabobra code and additional electronic components soldered in place
    • Covered with double-wall heat shrink for protection
  • Waterproof reed switch
  • Hand wound electromagnet coil
  • All wiring in place and secured
  • Light weight plugs between components to assist with install
  • Bosch LPP cable
  • Magnet for disc rotor
  • Some strips of double-sided tape for reed switch and coil
  • Short install guide to assist with connection/placement/troubleshooting
Total cost per device would be 99USD/80GBP/90EUR or equivalent in your favourite currency. This include shipping worldwide. Payment by Paypal.

Now to manage expectations, this isn't a commercial product. The finish isn't going to be as nice as you might get in a product off the shelf simply because I don't have access to the customisation that large scale affords. For example, where the big companies might have a reed switch with custom-length cable for the perfect fit, I'll instead need to extend that cable myself to make it work. However, all builds would be carefully assembled and tested prior to going out, and I'd be happy to replace any that are not working.

The idea with this is that you unpack the device, feed the reed switch through the frame, position the coil, plug in the LPP and get going ASAP - probably an hour's install on the first run giving it's pretty tight around the motor on some frames?

IMPORTANT
Running from the LPP on the motor requires that port to be activated. If it's not already activated, you'll need to have your local dealer enable it. That's done through the USBC connection on the smart controller on your bars.

There's no integration with the Kiox display, so the display will work as before though all metrics will be offset by the multiplier value you choose. I've been running my device on Bosch's latest firmware version, but critically, ensure you're not using GPS when running the device - I've got no confirmation on this, but I would expect detection if GPS speed doesn't agree with sensor reported speed.

Assuming there's still interest now that you know the pricing, please like/reply to this if you're happy to go ahead so I can understand numbers for the components I'll need to bring in. Time frame wise, it would probably be 4-6 weeks before I can get any devices out due to the lead time with these required components. Ordering just be through Private Message where you can specify the required multiplier and wheel circumferance for your setup.

Thanks all.
Sounds good to me!
 

tatane

New Member
Jun 25, 2023
59
41
Southern France
Thanks for all the posts and messages with interest in the megabobra. I've spent some time sourcing components that would be needed for this project and worked out some costing.

This would comprise all necessary components to install the megabobra to replace the rim magnet, including the genuine Bosch LPP cable to plug into the motor:
  • Arduino loaded with megabobra code and additional electronic components soldered in place
    • Covered with double-wall heat shrink for protection
  • Waterproof reed switch
  • Hand wound electromagnet coil
  • All wiring in place and secured
  • Light weight plugs between components to assist with install
  • Bosch LPP cable
  • Magnet for disc rotor
  • Some strips of double-sided tape for reed switch and coil
  • Short install guide to assist with connection/placement/troubleshooting
Total cost per device would be 99USD/80GBP/90EUR or equivalent in your favourite currency. This include shipping worldwide. Payment by Paypal.

Now to manage expectations, this isn't a commercial product. The finish isn't going to be as nice as you might get in a product off the shelf simply because I don't have access to the customisation that large scale affords. For example, where the big companies might have a reed switch with custom-length cable for the perfect fit, I'll instead need to extend that cable myself to make it work. However, all builds would be carefully assembled and tested prior to going out, and I'd be happy to replace any that are not working.

The idea with this is that you unpack the device, feed the reed switch through the frame, position the coil, plug in the LPP and get going ASAP - probably an hour's install on the first run giving it's pretty tight around the motor on some frames?

IMPORTANT
Running from the LPP on the motor requires that port to be activated. If it's not already activated, you'll need to have your local dealer enable it. That's done through the USBC connection on the smart controller on your bars.

There's no integration with the Kiox display, so the display will work as before though all metrics will be offset by the multiplier value you choose. I've been running my device on Bosch's latest firmware version, but critically, ensure you're not using GPS when running the device - I've got no confirmation on this, but I would expect detection if GPS speed doesn't agree with sensor reported speed.

Assuming there's still interest now that you know the pricing, please like/reply to this if you're happy to go ahead so I can understand numbers for the components I'll need to bring in. Time frame wise, it would probably be 4-6 weeks before I can get any devices out due to the lead time with these required components. Ordering just be through Private Message where you can specify the required multiplier and wheel circumferance for your setup.

Thanks all.
I've seen a few interested people (including me) haven't reached the 10 post requirement to be able to DM member yet and would hate to see some having to do "shitposting" on these forums just to get there ... maybe create a dedicated thread for that so you have a nice list of people you may have to DM first due to low postcount ? Maybe something can be worked out on your profile by forum admins to lift that limit, but would you really want that ? (as it would come with all the potential spam this is supposed to prevent).

Also, seeing some bad experiences other have had with such endeavors here and in other forums in the past, I would likely require upfront payments before ordering any parts, as you can easily have a lot of people getting all of a sudden unresponsive when you have everything lined up for delivery and just awaiting payments to send devices around ... just my .2cents tho ;)
 

Ashley3283

New Member
Jun 27, 2023
16
4
UK
The ports and cables have already been mentioned in this thread, but here's some more information/reminder (taken from elsewhere as they also provided some extra information in German which will make it easier for some).

View attachment 109791

View attachment 109792

Some bikes will have LPP and HPP or lights enabled by default.

Some manufactures theoretically can/will have locked out access to the LPP/HPP and it won't always be possible to enable these.

I think the display/kiox port has two data pins and two for a power circuit, red and black in the cable (5v I think, but could be 12v like all the other ports and step down to 5v at the Kiox ?). Not sure if you could also splice/use splitter/take off from here as you're only pulling a tiny current.
Looking at this post it appears the speed sensor is only 3.3v, is this enough to power the Arduino if I was to cut the wire and put between the sensor and the motor?
 

tatane

New Member
Jun 25, 2023
59
41
Southern France
Looking at this post it appears the speed sensor is only 3.3v, is this enough to power the Arduino if I was to cut the wire and put between the sensor and the motor?
AFAIK arduino nano operates at a minimm of 5V (and supports up to 20V, hence why we can use the 12V lights port there), so that would likely not be enough to power the arduino
 

Ashley3283

New Member
Jun 27, 2023
16
4
UK
AFAIK arduino nano operates at a minimm of 5V (and supports up to 20V, hence why we can use the 12V lights port there), so that would likely not be enough to power the arduino
Ok thanks, since the LPP and speed sensor use the same plug I am therefore unable to access the LPP. Can I run the Arduino off the HPP?
 

megabobra

Active member
Jul 24, 2022
220
237
Australia
Alternatively would an Arduino Pro Mini 328 - 3.3V/8MHz work instead of a Nano?
Hi Ashley,

The high power port, HPP, will work just as well as the LPP but you'll need to get it turned on by the dealer.
3.3v will run the Pro Mini, but I'm not sure it'll be enough voltage to drive the coil and generate a sufficient magnetic field for the motor. There's no harm in giving it a try though!
 

Ashley3283

New Member
Jun 27, 2023
16
4
UK
Thanks Megabobra, I was planning not to run an additional reed switch and coil. I was planning on having the 3.3v powering the Pro Mini, when the magnet passes the existing switch that goes into the Arduino which delays it and then sends it back via the existing cable. Would that work? Not sure where I'd pick up the negative if I use the existing LPP/Speed sensor plug though
 

Ashley3283

New Member
Jun 27, 2023
16
4
UK
I was also planning on having the multiplier set at 1.6 then change my display to kph which would actually read an approximate mph reading?
 

megabobra

Active member
Jul 24, 2022
220
237
Australia
Thanks Megabobra, I was planning not to run an additional reed switch and coil. I was planning on having the 3.3v powering the Pro Mini, when the magnet passes the existing switch that goes into the Arduino which delays it and then sends it back via the existing cable. Would that work? Not sure where I'd pick up the negative if I use the existing LPP/Speed sensor plug though

Ahh understood, I'm following now. Sorry, I'm not sure. My thought is that yes, the arduino is certainly capable of doing what you need, with a quick code update of course. BUT it depends on what the existing bosch speed sensor is doing - it may not just be a simply reed switch. Since you mention there's power there, it could be that it even has some components in there allowing it to report some kind of digital response when the wheel magnet passes, rather than a simple open/close circuit. On the other hand, it could be a simple reed switch, and if so, the arduino could mimic it easily.

If you're interested in investigating it, I suggest unplugging the speed sensor and probing the connections with a multimeter to see what happens as the magnet passes the sensor. Of particular interest would be the resistance that it gives when the circuit is closed, as this resistance amount would be a cheap and easy way for Bosch to check that sensor hasn't been tampered with.

Naturally this method can work as it's the typical means of derestriction that most commercial devices use, but it'd need a bit of experimentation to get up and running.
 

Ashley3283

New Member
Jun 27, 2023
16
4
UK
Ahh understood, I'm following now. Sorry, I'm not sure. My thought is that yes, the arduino is certainly capable of doing what you need, with a quick code update of course. BUT it depends on what the existing bosch speed sensor is doing - it may not just be a simply reed switch. Since you mention there's power there, it could be that it even has some components in there allowing it to report some kind of digital response when the wheel magnet passes, rather than a simple open/close circuit. On the other hand, it could be a simple reed switch, and if so, the arduino could mimic it easily.

If you're interested in investigating it, I suggest unplugging the speed sensor and probing the connections with a multimeter to see what happens as the magnet passes the sensor. Of particular interest would be the resistance that it gives when the circuit is closed, as this resistance amount would be a cheap and easy way for Bosch to check that sensor hasn't been tampered with.

Naturally this method can work as it's the typical means of derestriction that most commercial devices use, but it'd need a bit of experimentation to get up and running.
Ok, I think the safest option would be to have a secondary reed switch picking up my rotor magnet then have an electromagnet inside the tube near my existing speed sensor. There are a lot of ifs and maybes with my idea.

Quick question, why don't you relocate your rim magnet sensor and put the electromagnet near that rather than trying to find the correct location on the motor?
 

megabobra

Active member
Jul 24, 2022
220
237
Australia
Ok, I think the safest option would be to have a secondary reed switch picking up my rotor magnet then have an electromagnet inside the tube near my existing speed sensor. There are a lot of ifs and maybes with my idea.

Quick question, why don't you relocate your rim magnet sensor and put the electromagnet near that rather than trying to find the correct location on the motor?

Because there is no rim magnet sensor :) Instead there's a hall sensor within the motor case itself!
 

I2ichie

New Member
Jun 21, 2023
9
6
Somerset, UK
Did you find a tuning chip for this Bosch smart system with the rim magnet? I’ve just purchased a Haibike AllMtn cf 11 with the latest Bosch motor and just found out I can’t de-restrict it 😳
 

GBikeBoy

New Member
Jul 4, 2023
8
4
New York
Hi All. Thought I’d share my experiences here. I have a Cube Reaction EXC. I did the low-tech speed fix and put the magnet on the pedal arm. This worked fine for a while until I hit a large pothole and I think the sensor moved. I got an 524001 error (same as the old 504). I put it all back to normal, rode for 90 mins and it cleared. That was strike 1.

I then got a Speedbox 1.0 fitted. I do long rides from Manhattan up to Piermont and after both long rides recently I got the same error again. Thus strikes 2 and 3. Although I left the bike on to do the count down every time, I think somehow the system just works out that I was doing an average of 40km/h and so it throws up the error.

So three strikes and I thought I was out. Well maybe there is hope! I took out the Speedbox and then set the bike up last night inside and cycled for 90 minutes. No joy. I then went out to Central Park today and cycled round and round for 90 minutes and it has just cleared.

Thus in summary :

1. It seems as though it is still possible to reset the system yourself with a limp home mode ride of 90 mins even after the third strike (although keeping my fingers crossed this is indeed the case!)

2. If you have a Speed box fitted and do long rides, be careful. I think trying to keep around 35-40km/h might be the best way to avoid the chip detection.

Hope this helps. If anyone has had similar experiences with a Speedbox 1.0 let me know. With credit to ebiketuner where I bought it, they have been very helpful.
 

Onetime

Active member
Aug 10, 2022
349
351
Cali
I‘ve heard that if you don’t use the flow app and you don’t ride above 25mph for extended periods of time, then you shouldn’t get any error codes. So I’ve heard.
 

GBikeBoy

New Member
Jul 4, 2023
8
4
New York
Well ebiketuner just recommended I send back the Speedbox 1.0 and swap it for a Volspeed. Apparently far fewer issues with that system.
 

Ashley3283

New Member
Jun 27, 2023
16
4
UK
Apologies for the repost of some of this, but this single post can be a single point of reference for the rim magnet derestrict.

My build is based on an Ardunio microcontroller, reed switch and electromagnet. I removed the bike's rim magnet and instead placed a traditional magnet on the disc rotor. The Arduino then uses the reed switch to sense the true RPM of the wheel, delays the time between magnet passes by a fixed multiplier and then activates the electromagnet at the new interval accordingly. The electromagnet is positioned up against the motor case.

With ~100 lines of code, everything is working great. I've got the multiplier set to 1.4 (eg where true speed is 20kph, motor will be shown 20/1.4= 14.3kph), giving a new max assisted speed of 35kph. The multiplier could be set to anything, say 2 would give assist to 50kph.

The beauty of this setup is the simplicity: no interruption of sensors from the motor, reducing chance of detection. So long as you don't go crazy with the multiplier, it'd be very difficult for the motor to detect this manipulation, as there are so many real-world variables which will mask it; rider weight, gear ratio, terrain etc. Some things may give it away though. For example, if you use a large multiplier, you may reach a point where for a given cadence it's just not physically possible to be traveling so slowly. Also if you use location tracking through the Eplus app, it may compare wheel speed with GPS speed and flag a discrepancy.

Some FAQ:

  • YES it will disrupt your total trip distance and odometer, but it's a simple multiplication to get the true figures. ie reported trip distance * chosen multiplier = true trip distance.
  • YES it should work on setups without the rim sensor. Instead of positioning the elctromagnet against the motor case, position it against the speed sensor.
  • Total power usage when the magnet is firing is ~2.4watts, and negligable when it's not firing (ie when the bike is stationary). Magnet is firing only around 8% of the time.


Here's a quick tutorial so you can build your own derestrictor for the smart system with rim magnet.

Components:
Of course there's plenty of equivalent components you can substitute here, so go with what's cheap/easy to get locally.


Wiring Schematic:

Reed switch: D8 and Ground
Transistor: Base > Ground, emitter > electromagnet, collector > D3
Electromagnet: 5v and transistor's collector leg
Voltage regulator: 5v and Ground

View attachment 105957

The Arduino nano has a built in regulator, so you can also wire the ~13v from the Bosch low power port direct to the Vin and Ground pins in order to omit the voltage regulator above. I had a spare regulator so figured I'd use it to monitor temperatures.

Note that you'll need your Bosch dealer to enable to the low power port before it will be powered.

I was also able to build my own electromagnet with some enameled copper wire. You need a coil resistance of ~15ohms. I used 100 turns around some pvc pipe ~ 25mm in diameter and a 0.5watt 10ohm resistor.

View attachment 105975

These work just as well as the commercial electromagnet and offer better flexibility of placement. If i was starting from scratch, it'd use this rather than the off the shelf product.


Programming

Load the attached code to the Arduino Nano with Arduino IDE. You can download it here.

You can update the Multiplier variable in the code (line 26) to alter the maximum assistance speed. I've got mine set to 1.4. This slows the actual wheel rpm by a factor of 1.4, moving the maximum assistance speed from 25kph to 35kph.


Installation

Snap the magnet on to the rear disc rotor. Mount the magnetic switch on the swing arm so that it's close to the rotating magnet.
The placement of the electromagnet is a bit tricky as the motor measures the strength of the magnet field, not just if a field exists. I found it best to mount the magnet facing AWAY from the motor (ie magnetic face towards the rear of the bike). Refer to the pics attached for my placement location. I'm using some foam to wedge it in place.

Once wired, the Arduino Nano and all wiring gets pushed into the frame.



Good luck and let me know if there are any questions. View attachment 105963 View attachment 105964 View attachment 105965 View attachment 105976 View attachment 105977
Sorry, quick question on the transistor. In your diagram you have emitter to electromagnet, base to D3 and collector to ground but the description says Base to Ground, emitter to electromagnet and collector to D3.

Please can you confirm which is correct?

Thanks
 

megabobra

Active member
Jul 24, 2022
220
237
Australia
Sorry, quick question on the transistor. In your diagram you have emitter to electromagnet, base to D3 and collector to ground but the description says Base to Ground, emitter to electromagnet and collector to D3.

Please can you confirm which is correct?

Thanks
Thanks Ashley, the diagram is correct. I've updated the wording in that post to confirm:
Transistor: Base > D3, emitter > electromagnet, collector > Ground
 

Koekie

New Member
May 2, 2023
22
38
Antwerp, Belgium
Unfortunately I got 524001 today. This was after 1030 km with the system installed. (1030 km as shown on the Bosch display, probably in reality close to 2000 km)
@megabobra, how many km did you do with your system/code?
 
Last edited:

EMTB Forums

Since 2018

The World's largest electric mountain bike community.

513K
Messages
25,114
Members
Join Our Community

Latest articles


Top