Bosch Smart motor 2022 - walk assist problems

Tuan

Member
Jul 24, 2023
2
1
Switzerland
I recently bought a new Trek Rail 9.8 XT electric bike which has a new Bosch 2022 smart motor, a 750 Wh battery and a new Kiox 300. On my first ride I tried the walk assist and found it to be useless as it is. When you activate the walk assist with the - button, the bike moves 2-3 metres, then comes to a complete stop and starts to move again a second later. This cyclical action is completely contrary to all the walk assist that my previous bikes had. When my dealer-servicer contacted Bosch in Germany, he was told that it is a new smart system which works different. Well now I don't know whether my bike is not working properly or whether I am crazy. The Bosch technician remotely connected to the bike and made a new setting. The diagnostics were OK. After this operation the walk function is still unusable. The bike behaves similarly in all types of inclines; be it a trail with drops or a paved road. Walk assist works discontinuously and when you walk alongside the bike you feel miserable. I don't know if anyone has had a similar experience?
Hi Nejc,
I also own a Trek 9.8 XT. I bought it in Sept. 2022. I have exactly the same problems with its Walk function. I showed my dealer your EMTB forum post and he forwarded it to Bosch Switzerland. They adviced him, to replace the Kiox remot controll unit on my bike. That didn't help. He promised me to do further investigations. Problem has not been solved until today.
Could you ever solve the problem on your Bike? I would appreciate any possible help.
Thank you.
 

militantmandy

Well-known member
Jan 18, 2022
399
369
Tweed Valley, Scotland
I also have the most recent Whyte E160. Mine does not do this, but I am always pushing at least a little as use it to get it up the stairs to my flat (which it does superbly) or when I am sessioning trails. If you gently push from the saddle, does it still do it?
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,568
5,060
Weymouth
as a bove I have the Whyte E160 RSX..........walk assist works perfectly so does not look like a generic Bosch Smart issue.
 

Tonytank

Member
Jun 5, 2019
100
77
London
I was told by my lbs that when in walk mode the motor has to sense an intial push movement to activate it.
So you select walk, hold down the button and give it a littke push and it will start, if you just hold down the button and it doesnt sense any movement it will not activate. Took me a couple of goes to get used to it but it worked fine
 

Paul Mac

E*POWAH Elite World Champion
Patreon
Subscriber
Jul 9, 2018
997
1,046
Uk
Hi Nejc,
I also own a Trek 9.8 XT. I bought it in Sept. 2022. I have exactly the same problems with its Walk function. I showed my dealer your EMTB forum post and he forwarded it to Bosch Switzerland. They adviced him, to replace the Kiox remot controll unit on my bike. That didn't help. He promised me to do further investigations. Problem has not been solved until today.
Could you ever solve the problem on your Bike? I would appreciate any possible help.
Thank you.
Walk mode doesn't work on the Trek smart system, unless you change from disc mounted speed sensor to rim mounted magnetic, then it works perfectly.
 

nandewar

Member
Aug 13, 2020
25
6
Australia
Walk mode doesn't work on the Trek smart system, unless you change from disc mounted speed sensor to rim mounted magnetic, then it works perfectly.
The Focus has a disc mounted speed sensor as well. How do you swap from the disc to a rim mounted sensor? And why would some disc mounted bikes work and not others?
 

Paul Mac

E*POWAH Elite World Champion
Patreon
Subscriber
Jul 9, 2018
997
1,046
Uk
The Focus has a disc mounted speed sensor as well. How do you swap from the disc to a rim mounted sensor? And why would some disc mounted bikes work and not others?
TREK use a proprietary speed sensor (don't know about Focus), which is why Trek bikes had the speed issue earlier this year after a software update.
There is a speed sensor built into the Bosch gen 4 motor, you have to go to a Bosch dealer and they can switch the speed sensor pickup from the external sensor to the motor sensor.
You then have to add the rim mounted magnetic to your wheel.
valve.
This is all reversible if you ever what to change back.
I personally did this on my Trek Rail as did a friend, it 100% works on the Trek.
 

andybobbill

Member
Aug 9, 2023
28
15
UK
TREK use a proprietary speed sensor (don't know about Focus), which is why Trek bikes had the speed issue earlier this year after a software update.
There is a speed sensor built into the Bosch gen 4 motor, you have to go to a Bosch dealer and they can switch the speed sensor pickup from the external sensor to the motor sensor.
You then have to add the rim mounted magnetic to your wheel.
valve.
This is all reversible if you ever what to change back.
I personally did this on my Trek Rail as did a friend, it 100% works on the Trek.
Well that's annoying. Has anyone managed to get a Rail working with the stock speed sensor, or can a non-trek speed sensor be used instead? I have asymmetric rims so not convinced a rim magnet will play nice, nor do I particularly want to take it to a dealer to have something enabled in order to fix something that should work in the first place.
I hate proprietary gear...
 

ViperBoy

New Member
Dec 19, 2023
4
0
Cupertino, CA
Any updates on Trek walk issues? I have both a 2020 (slow start, but otherwise works fine) and 2022 Rail 9.9 which is utterly useless and broken. The 2022 has an even slower start, weaker push and cuts out every couple of seconds. I only need walk on crazy steep 30+ degree slopes I can barely even walk up, so it is very important when used
 
Oct 30, 2020
24
34
Northern Ireland
Any updates on Trek walk issues? I have both a 2020 (slow start, but otherwise works fine) and 2022 Rail 9.9 which is utterly useless and broken. The 2022 has an even slower start, weaker push and cuts out every couple of seconds. I only need walk on crazy steep 30+ degree slopes I can barely even walk up, so it is very important when used
i agree. mine is the exact same. i came from a shimano ep8 and compared to that, the walk is absolutely useless
 

Plummet

Flash Git
Mar 16, 2023
1,152
1,634
New Zealand
hmmm. I have the same issue on my Voima 23 voima after a speed sensor update.....
Did anyone actually find a solution.
 

andybobbill

Member
Aug 9, 2023
28
15
UK
hmmm. I have the same issue on my Voima 23 voima after a speed sensor update.....
Did anyone actually find a solution.
Interesting. Do you have a bosch speed sensor or is it different like the Rail?
Still no luck my end. I asked Bosch, they said take it to a shop and they could change the speed settings on the walk mode, but if you wanted to use a rim magnet the shop would need authorisation from Trek (fecking why???) to switch it on.
Pointlessly proprietary stuff is the reason I stopped buying Specialized bikes. I still can't escape it.
 

Plummet

Flash Git
Mar 16, 2023
1,152
1,634
New Zealand
Interesting. Do you have a bosch speed sensor or is it different like the Rail?
Still no luck my end. I asked Bosch, they said take it to a shop and they could change the speed settings on the walk mode, but if you wanted to use a rim magnet the shop would need authorisation from Trek (fecking why???) to switch it on.
Pointlessly proprietary stuff is the reason I stopped buying Specialized bikes. I still can't escape it.
I have the bosch rotor magnet speed sensor.
 

Yoak

Active member
Apr 5, 2020
256
172
Norway
The solution is to go to a dealer and hook up your bike to the Bosch diagnostic tool. Then you can increase the walk speed up by a few km/h. Did it with mine and it works great
 

arTNC

Member
Feb 1, 2024
240
281
Texas
OP, I can understand your frustration with this walk issue. I loved the suggestion of carrying a 50 pound emtb up a nasty climb. Man, if I could do that I wouldn't even need an emtb. :ROFLMAO: But seriously there are places where walk is needed or at the very least an aid to get over ledges, loose rocks, or other trail issues where the trail is already steep enough to be a little difficult to walk, much less push or carry a 50 pound bike.

My immediate local trails never require the walk feature on my 2022 Gen 2 Trek Rail 7. However, I also ride out at an off road ranch where the 100 miles of singletrack were designed and setup for dirt motors. It is a rocky, ledgy, often rutted terrain with very steep climbs and pitches. Even prime level MTB riders can't make a lot of these climbs just because of lack of speed and traction, but overall the riding is great, so you can rely on the walk feature to get to the top of such nastiness.

Of course my Rail 7 has the Purion display, and it will pull up these nasty sections with no issue. However, as has been mentioned, you need to be in the right gear sometimes for optimum climbing efficiency. I've never experienced the on-again-off-again climbing issue unless my thumb slipped off the (+) button for forward movement. And if I'm in a higher gear, sometimes the bike will just about pull me and it along over some really tough terrain.

It's very clear that the Bosch CX motor has the ability to have an awesome walk feature as evidenced by the Purion display examples. So it seems really odd that Bosch can't figure out how to get the fancier displays to play nice with the walk feature.
 

Yoak

Active member
Apr 5, 2020
256
172
Norway
I have had no problem with walk mode on my Rail 9.8 for at least 6 months. It was very (too) slow in the beginning, and behaved a bit weird. Now I´m on the latest Firmware on the bike, and I increased the speed of the walk mode form (the standard) 3,3km/h to maximum 4,5km/h. As stated earlier, the speed increase has to be done using the Diagnostic tool, at a dealers place.
 

andybobbill

Member
Aug 9, 2023
28
15
UK
Update from me (Trek Rail 9.8 2023). I ended up going to the dealer and having them up the walk mode top speed. No difference, still crap. Haven't gone down the route of using a rim magnet yet as this requires authorisation from Trek and reprogramming etc. Why should life be simple huh?
Anyway, today on a hunch I started fiddling with the rotor mounted magnet. I've swapped it for a Hope magnet, put spacers behind it, swung it out further from the axle, all the things people have suggested elsewhere. No dice. Then for a laugh I turned it around completely, reversing the polarity of the magnet...

It works.

Well, walk mode works perfectly now, but the speed doesn't register and I get an error code. Switch it back and restart, same as before. Switch it back again and restart, now walk mode works AND the speed is registering! At the time of writing it now functions perfectly. I'll keep an eye on it.

So it seems that either some of the magnets were assembled wrong, or some of the Trek speed sensors were wired wrong, possibly both? I don't have the kit to test polarity etc, nor do I know how it's supposed to function but I do know that I now have a bike that works as it should, finally.

Hope this helps someone else, do have a poke at your magnet and see how it works out. Turns out you can remove it without having to remove the wheel every time so that's a great help in the process of experimentation.

IMG_3122.JPG
 
Last edited:

Arminius

E*POWAH Master
Subscriber
Jul 26, 2022
604
1,034
Rhein-Ruhr Delta, Germany
Update from me (Trek Rail 9.8 2023). I ended up going to the dealer and having them up the walk mode top speed. No difference, still crap. Haven't gone down the route of using a rim magnet yet as this requires authorisation from Trek and reprogramming etc. Why should life be simple huh?
Anyway, today on a hunch I started fiddling with the rotor mounted magnet. I've swapped it for a Hope magnet, put spacers behind it, swung it out further from the axle, all the things people have suggested elsewhere. No dice. Then for a laugh I turned it around completely, reversing the polarity of the magnet...

It works.

Well, walk mode works perfectly now, but the speed doesn't register and I get an error code. Switch it back and restart, same as before. Switch it back again and restart, now walk mode works AND the speed is registering! At the time of writing it now functions perfectly. I'll keep an eye on it.

So it seems that either some of the magnets were assembled wrong, or some of the Trek speed sensors were wired wrong, possibly both? I don't have the kit to test polarity etc, nor do I know how it's supposed to function but I do know that I now have a bike that works as it should, finally.

Hope this helps someone else, do have a poke at your magnet and see how it works out. Turns out you can remove it without having to remove the wheel every time so that's a great help in the process of experimentation.

View attachment 136953
Treks seem different but consideration of this helped other users with similar probs, Bosch manual:

Switching the push assistance on/off
The push assistance aids you when pushing your eBike. The speed in this function depends on the selected gear and can reach a maximum of 6 km/h. The lower the selected gear, the lower the speed of the push assistance function (at full power).

To start walk assistance, press the (8) button for more than 1 s and keep it pressed. The battery charge indicator (3) goes out and a white moving light in the direction of travel shows that it is ready.

To activate walk assistance, one of the following actions must occur within the next 10 s:
– Push the eBike forwards.
– Push the eBike backwards.
– Perform a sideways tilting movement with the eBike. After activation, the motor begins to push and the continuously filling white bars change colour to ice-blue.

If you release the (8) button, walk assistance is paused. You can reactivate walk assistance within 10 s by pressing the (8) button.

If you do not reactivate walk assistance within 10 s, walk assistance automatically switches off.

Walk assistance is always ended if:
– the rear wheel jams;
– the bicycle cannot move over ridges;
– a body part is blocking the bike crank;
– an obstacle continues to turn the crank;
– you start pedalling;
– the (9) button or on/off button (1) is pressed.

The push assistance function is subject to local regulations; the way it works may therefore differ from the description above, or the function may even be deactivated completely.
 

arTNC

Member
Feb 1, 2024
240
281
Texas
Treks seem different but consideration of this helped other users with similar probs, Bosch manual:

Switching the push assistance on/off
The push assistance aids you when pushing your eBike. The speed in this function depends on the selected gear and can reach a maximum of 6 km/h. The lower the selected gear, the lower the speed of the push assistance function (at full power).

To start walk assistance, press the (8) button for more than 1 s and keep it pressed. The battery charge indicator (3) goes out and a white moving light in the direction of travel shows that it is ready.

To activate walk assistance, one of the following actions must occur within the next 10 s:
– Push the eBike forwards.
– Push the eBike backwards.
– Perform a sideways tilting movement with the eBike. After activation, the motor begins to push and the continuously filling white bars change colour to ice-blue.

If you release the (8) button, walk assistance is paused. You can reactivate walk assistance within 10 s by pressing the (8) button.

If you do not reactivate walk assistance within 10 s, walk assistance automatically switches off.

Walk assistance is always ended if:
– the rear wheel jams;
– the bicycle cannot move over ridges;
– a body part is blocking the bike crank;
– an obstacle continues to turn the crank;
– you start pedalling;
– the (9) button or on/off button (1) is pressed.

The push assistance function is subject to local regulations; the way it works may therefore differ from the description above, or the function may even be deactivated completely.
This has been an interesting thread, and it's curious how different the simple Purion display bikes and the Smart System bikes operate in walk mode. I kind of like the way "walk" operates on my Gen 2 Rail 7/Purion. Yeah, the speed depends on what gear you're in, but that thing will literally climb over just about anything as long as I keep my finger on the "+" button, and if the terrain is somewhat loose the rear tire will spin and almost dig a hole...LOL! In some instances the bike will almost pull me up a steep incline on a trail. Now this is not a problem, as all you have to do is let off the "+" button and it instantly stops.

I ride a lot at an off road ranch where we have dirt motor enduros on gnarly, rocky single track and such, so the terrain often has no flow for MTB's with lots of steep pitch-ups where even on Turbo the bike doesn't make it all the way up. The walk feature has been a life saver, and it's a shame that the "supposed" improved and more modern technology has lost some of that capability.

Arminius, reading the function directions, it seems really apparent that they've changed quite a bit on that newer system. I don't have to move the bike at all for "walk" to start up. That part where it states that walk will stop when the front wheel is stopped at a ridge...this is where mine will eventually climb over that ridge or the back wheel will spin. I'm thinking maybe some of this involves some kind of safety or liability concern from Bosch on the newer walk feature. I do have to pay attention to how I use it or the bike will almost get away from me...LOL!...but I really like its power and capability.
 

andybobbill

Member
Aug 9, 2023
28
15
UK
It's not so much that there is fundamental difference between the old and newer versions, it's that there is a glaring technical error seemingly caused by Trek's use of the proprietary speed sensor cable and/or magnet. Every other bike brand on the smart system has no issues it seems, and now that mine is working properly, neither do I. It does seem ridiculous that given the pages of discussion around this issue, nobody at Trek or Bosch appears to be aware of the problem or able to solve it. In the dealer the other day, there was talk of replacing the motor unit! If it turns out this is a simple magnet orientation or mis-wiring issue as it appears after my revelation yesterday, I wonder how many motors have been replaced because of this and still to o avail?
 

Hattori-Hanzo

Well-known member
Apr 10, 2023
425
567
UK
I'm not sure of this, I have a 22 cube which i have not done a system update on until recently. Before doing the update the walk assist worked in the same way as @arTNC described, full power at the push of the button with little to no delay.
Since doing the update walk mode has changed dramatically.
It now takes an age to get going, has a very slow initial pick up and upon any resistance seems to reduce power or cut out entirely.

I used the feature in a similar way to @arTNC and much prefer how it used to be.
I understand this may not suit everyone, and some may prefer the new version.
Personally I'd like to see the ability to adjust the walk assist feature in the flow app, then we could tailor it to our own needs.
 

andybobbill

Member
Aug 9, 2023
28
15
UK
I'm not sure of this, I have a 22 cube which i have not done a system update on until recently. Before doing the update the walk assist worked in the same way as @arTNC described, full power at the push of the button with little to no delay.
Since doing the update walk mode has changed dramatically.
It now takes an age to get going, has a very slow initial pick up and upon any resistance seems to reduce power or cut out entirely.

I used the feature in a similar way to @arTNC and much prefer how it used to be.
I understand this may not suit everyone, and some may prefer the new version.
Personally I'd like to see the ability to adjust the walk assist feature in the flow app, then we could tailor it to our own needs.
Adjusting in the app would be the dream/sensible option. I’ll not hold my breath though!
 

arTNC

Member
Feb 1, 2024
240
281
Texas
I'm going to have to express some ignorance here on the update issue for emtb's. Working part time at a Trek/Specialized/Santa Cruz shop in my retired years, I never messed with the software that these bikes interface with. Recently when I got my Trek Rail 7 (Purion display), I had my buddy, a fellow employee there, do whatever magic hookup this software performs. My only requirement to him was to give me all the power and speed potential this Bosch CX motor is capable of...so he did.

I have been riding the wheels off of this thing and have no complaints. So...my limited knowledge and time with the bike and software causes me to think...why would I want to hook up my bike to the magic black box from Bosch to change anything? I see the term "update" referred to in many, many threads. If I don't update will my bike quit working...turn into a 1960's Schwinn...explode?

I just got through living with a 2003 SC Bullit that I converted with a Bafang BBSHD mid-drive. I rode that bike off road for 3 years and had a blast with it. It surprisingly made a very good emtb. At the onset, I had to program the motor myself to tune the power delivery to my liking for off road, and after that I never touched the software again...just rode the crap out of it.

I'm not trying to be a smart ass about this. In fact I'm probably classified more correctly as a dumbass on this issue.:(
So, back to my original question...if you like what you have with the state of the software on your emtb, is it a requirement to update? I really like what I have with my Rail's performance. So, if I don't change anything, will I die?:ROFLMAO:
 

andybobbill

Member
Aug 9, 2023
28
15
UK
I'm going to have to express some ignorance here on the update issue for emtb's. Working part time at a Trek/Specialized/Santa Cruz shop in my retired years, I never messed with the software that these bikes interface with. Recently when I got my Trek Rail 7 (Purion display), I had my buddy, a fellow employee there, do whatever magic hookup this software performs. My only requirement to him was to give me all the power and speed potential this Bosch CX motor is capable of...so he did.

I have been riding the wheels off of this thing and have no complaints. So...my limited knowledge and time with the bike and software causes me to think...why would I want to hook up my bike to the magic black box from Bosch to change anything? I see the term "update" referred to in many, many threads. If I don't update will my bike quit working...turn into a 1960's Schwinn...explode?

I just got through living with a 2003 SC Bullit that I converted with a Bafang BBSHD mid-drive. I rode that bike off road for 3 years and had a blast with it. It surprisingly made a very good emtb. At the onset, I had to program the motor myself to tune the power delivery to my liking for off road, and after that I never touched the software again...just rode the crap out of it.

I'm not trying to be a smart ass about this. In fact I'm probably classified more correctly as a dumbass on this issue.:(
So, back to my original question...if you like what you have with the state of the software on your emtb, is it a requirement to update? I really like what I have with my Rail's performance. So, if I don't change anything, will I die?:ROFLMAO:
Mine was delivered with a useless walk mode, so I didn't have the option to not mess it up.
 

arTNC

Member
Feb 1, 2024
240
281
Texas
Mine was delivered with a useless walk mode, so I didn't have the option to not mess it up.
Yes, I understand that and totally get why you wanted to tweak the software. I'm just curious about whether it is required in some way to get an update if you're perfectly happy with how your emtb is performing.
 

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