Bosch CX shutting down when going over 20mph on my 2023 Orbea Wild

RacerX

Member
Nov 19, 2023
30
30
Austin Texas
Ok this must be insane. When doing a quick down and up I noticed it seemed my Bosch CX was shutting off. I thought I was hitting the remote by mistake and found I was not. So I actually read the motor manual and it said if you exceed 20mph it turns the motor off. What kind of insane genius came up with that idea? Someone sitting in a lab that has never ridden a MTB in their life. Anyone know a fix for this? I am hoping I am wrong and someone corrects me. 😵‍💫
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,637
5,110
Weymouth
it does not switch the motor off, it cuts the motor support. Your bike is an EPAC and just like every legal EPAC the nominal power output of the motor is restrcited to 250 w ( although not the max output which can be up to 550 w), and assisted speed is restricted to 20 mph iin your neck of the woods.........15.5 mph here in the UK and most of Europe.
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,637
5,110
Weymouth
It’s the agreement that was made so pedal assist can safely share trails with bikers.
afraid not! The criterea for EPACS was decided on the basis of allowing those motor equipped bikes that complied with the regulations to be classed as bicycles rather than mopeds or motorcycles. It was a hard fought battle with the agencies in support of preventing such bikes being classed as motocycles/mopeds winning albeit at the cost of speed/power restrictions that are...in many riders views.....set too low. For the manufacturers it meant they could a void the expensive process of Type Approval. For purchasers of EPACS it meant they did not have the same legal requirements of motorcycles/mopeds ( in most territories)......vehicle registration, road tax, insurance,.......lights, indicators, road legal tyres, compulaory helmets etc.

The specifications were first laid out by the EU and applied throughout all member states. Other Territories either adopted the same specifications or mostly the same but with some different max assisted speeds. In some territories further classes of E bikes were approved ( e.g. Speed pedelecs) with much higher max assisted speeds ( e.g. 45kph).
From what I have read on here the EMTB situation in the US seems to vary from State to State and includes the banning of even the basic class of EPAC from trails used by MTBs..........so wherever you look it is a bit of mess really, and needs some review.
 
Last edited:

weihlac

Member
Oct 12, 2020
43
35
USA
Ok this must be insane. When doing a quick down and up I noticed it seemed my Bosch CX was shutting off. I thought I was hitting the remote by mistake and found I was not. So I actually read the motor manual and it said if you exceed 20mph it turns the motor off. What kind of insane genius came up with that idea? Someone sitting in a lab that has never ridden a MTB in their life. Anyone know a fix for this? I am hoping I am wrong and someone corrects me. 😵‍💫
I guess maybe, perhaps, sorta, you shoulda read the paperwork BEFORE you bought your bike. Or maybe used that new thingie called "google".
You have a Class I ebike, limited to 20 mph motor assist in the US (oops, I forget, Texas is not part of the US).
Here is some reading material about Class I, II, and III ebikes.

 

Onetime

Active member
Aug 10, 2022
468
480
Cali
Ok this must be insane. When doing a quick down and up I noticed it seemed my Bosch CX was shutting off. I thought I was hitting the remote by mistake and found I was not. So I actually read the motor manual and it said if you exceed 20mph it turns the motor off. What kind of insane genius came up with that idea? Someone sitting in a lab that has never ridden a MTB in their life. Anyone know a fix for this? I am hoping I am wrong and someone corrects me. 😵‍💫
All e-bikes in the US are limited to 20mph, but they can be derestricted. Derestricting bosch smart system
 

ebikemotorrepair

New Member
Nov 10, 2023
8
4
Franklin Tennessee
it does not switch the motor off, it cuts the motor support. Your bike is an EPAC and just like every legal EPAC the nominal power output of the motor is restrcited to 250 w ( although not the max output which can be up to 550 w), and assisted speed is restricted to 20 mph iin your neck of the woods.........15.5 mph here in the UK and most of Europe.
yeah we have it good here in the US at 20mph.

RacerX

Also there are speed and torque regulations that allow the different bikes to be compliant with certain riding infrastructure. Like trails and a class 1 e assist mountain bike is compliant to go wherever a regular mountain bike can go. However many of the municipal governments are not mandated to adapt the rules or regulations. But the federal government at least sets a standard to ensure safety etc for existing infrastructure in the cases where indigenous areas of states, counties, and cities when they choose to make rules or laws that accommodate the wishes of a particular voting population. This is where is really helps to get involved in your local scene. It works. and when it doesn't I guess you can always move LOL.​

 

jackamo

Active member
Subscriber
May 25, 2023
126
76
UK
Ok this must be insane. When doing a quick down and up I noticed it seemed my Bosch CX was shutting off. I thought I was hitting the remote by mistake and found I was not. So I actually read the motor manual and it said if you exceed 20mph it turns the motor off. What kind of insane genius came up with that idea? Someone sitting in a lab that has never ridden a MTB in their life. Anyone know a fix for this? I am hoping I am wrong and someone corrects me. 😵‍💫
Easy out , get a volspeed V4 👍
 

Bengy22

Member
Aug 25, 2022
126
85
USA
I don't get why people buy those... for the same money you can buy a really nice noisy off road motorbike that no doubt has far higher spec components.
Most the appeal of off road motorbikes is the sound surely.
I don't own one but see the appeal as someone who also has a motorcycle and license. You get to ride around breaking the law, without a license or insurance, go more places than a full blown gas bike would be allowed. (And before I get hate I wouldn't want these on mtb trails). I had a street legal dirt bike before and just riding around the neighborhood and you attract attention really fast. No one even bats an eye with those, I even asked a cop and they said they group those into the same as e scooter and ebikes, if you are following the road rules they don't care
 

Ark

Active member
Mar 8, 2023
464
391
Newcastle Upon Tyne
even asked a cop and they said they group those into the same as e scooter and ebikes, if you are following the road rules they don't care
Weird over here in the UK if your riding one of those fully electric bikes you get charged as if your driving an uninsured motor bike.
Although the police don't seem to be to keen on catching people riding them... seems like they just don't bother because the Media will cry if some little radgie gets hurt in a police chase.

I think Derestricted peddle assist ebikes are counted the same way though
 

Onetime

Active member
Aug 10, 2022
468
480
Cali
If I'm fully up to date it doesn't work.

Currently there are no aftermarket derestrict devices that work on the Bosch Smart System with a rear wheel based speed sensor magnet. The new motor has an internal speed sensor.

The only way around is:
1. Buying a Bosch external speed sensor the wiring for it and a brake disc magnet.
2. Fitting it to your bike(if it has the appropriate holes for wiring and space for the external sensor.
3. Finding a dealer that has the equipment and knowhow to deactivate the internal sensor and activate the external one.

The other way is a DIY system made by a member here on the forum, search for:

MEGABOBRA: Bosch Smart System Derestriction for Rim Magnet - DIY Project with Support​


👋
You’re not up to date. In addition to the DIY Megabobra system, there are currently two companies that make derestrictors for the rim magnet. Speedbox and e+, (links below). The original poster didn’t mention which sensor he had, so I wouldn’t assume it’s a rim magnet. And there are several companies that make derestrictors for the more common swingarm sensor/rotor magnet, (Speedbox, Peartune, Speedfun, e+, Volspeed etc) just to name a few.
Tuning chip for e-bikes with Bosch motors with Smart system and Rim Magnet - Package: BOX, Qty: 1 pcs

Bosch Smart System - Rim Magnet
 

emtbeast

Active member
Jan 10, 2022
309
352
Slovenia
You’re not up to date. In addition to the DIY Megabobra system, there are currently two companies that make derestrictors for the rim magnet. Speedbox and e+, (links below). The original poster didn’t mention which sensor he had, so I wouldn’t assume it’s a rim magnet. And there are several companies that make derestrictors for the more common swingarm sensor/rotor magnet, (Speedbox, Peartune, Speedfun, e+, Volspeed etc) just to name a few.
Tuning chip for e-bikes with Bosch motors with Smart system and Rim Magnet - Package: BOX, Qty: 1 pcs

Bosch Smart System - Rim Magnet
Yes I know about the chainstay/swingarm sensor, that's what I wrote about.
Didn’t know about Speedbox and e+ will look into that.✌️
Update: also deleted my post as the information contained was not up to date.
 
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Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,637
5,110
Weymouth
....deactivate the motor speed sensor....? Well here is a weird thing! My Bosch Smart System bike has the standard Bosch sensor/cable and magnet on the brake rotor. I had an instance where the sensor was completely pulled away from its housing and was left dangling from its cable on the floor. I got an error report on the Kiox 300........and it was an easy fix to fit it back in its holder and clear the fault report. The weird thing was that when it happened I did not lose all motor support. Instead the motor support pulsed on and off...............maybe suggesting a speed sensor in the motor was still operating but not at the correct rate. So a LBS using the Bosch software can prioritise which sensor ( motor or cable sensor) is prioritised, but does that a ctually disable the motor speed sensor??
 

emtbeast

Active member
Jan 10, 2022
309
352
Slovenia
....deactivate the motor speed sensor....? Well here is a weird thing! My Bosch Smart System bike has the standard Bosch sensor/cable and magnet on the brake rotor. I had an instance where the sensor was completely pulled away from its housing and was left dangling from its cable on the floor. I got an error report on the Kiox 300........and it was an easy fix to fit it back in its holder and clear the fault report. The weird thing was that when it happened I did not lose all motor support. Instead the motor support pulsed on and off...............maybe suggesting a speed sensor in the motor was still operating but not at the correct rate. So a LBS using the Bosch software can prioritise which sensor ( motor or cable sensor) is prioritised, but does that a ctually disable the motor speed sensor??
That's pretty interesting, maybe it's possible that both are working at the same time, with one that has priority, the other maybe serves as anti tampering somehow...just thinking...
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,637
5,110
Weymouth
That's pretty interesting, maybe it's possible that both are working at the same time, with one that has priority, the other maybe serves as anti tampering somehow...just thinking...

just to expand on that theory..............my bike worked perfectly after that for several weeks until one day I got the same pulsing on and off of motor support. It was only then that I realized when I thought...weeks before...I had refitted the sensor in its holder I had not in fact inserted it far enough for it to be "locked in" and it had rattled out a few mm. I fixed it in place properly this time. So it seems if the sensor is just a little too far from its correct position for the magnet the motor support goes into pulse on/off mode. If the sensor is completely removed from its holder, the motor support goes into pulse mode. normally in either scenario you would expect no motor support. So it seems tote me a speed sensor was still working and to do so it must be reacting to a magnet somewhere! The motor support pulsing on and off was consistent...not erratic.....1 second on 1 second off ( roughly). So maybe the motor sensor is still active and works with a magnet that is part of the motor drivetrain??
I certainly would not bet on any derestriction device working with the Bosch Smart system over any extended period of time especially if the Flow app is used.
 

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