• How to use this section. To the thread starter: Once you are satisfied with the answer that youve been given, click the Trophy on the left hand side of the message. This will rate this answer as the 'Best Answer' and will change the question status from 'Unanswerd' to 'Answered'. All members can also upvote an answer with the 'Up' arrow, this will help identify the best answer.

Why do I need a Bosch Software Update for changing a 11-50 to a 10-50 cassette?

target2804

New Member
Apr 26, 2023
55
80
Germany
Bosch and Haibike say I need a software update when changing the cassette because the motor is programmed for 11-50 on 38 sprockets and otherwise it can come to errors.

Do I get such an update from my bike dealer? Or must that first be released by Haibike and that is an unnecessarily long process?

I want to finally get rid of the PG-1210 cassette and would have immediately bought the GX-1275, but I can probably not drive. (Wheelset I have suitable with XD freewheel lying around at home).
 

target2804

New Member
Apr 26, 2023
55
80
Germany
So why do they tell me? :D And also there are reports of bikes not working anymore. There seems to be a minimum and a maximum gear ratio programmed in the motor software. And for me, I would run out of the lower limit with the 10-50 cassette.
 

Rostle32

Member
Sep 26, 2018
86
92
Uk
In my experience, Ive had no updates to my software on my 2020 Rail 7(gone from 12 speed, down to 10 speed,11-46 cassette) due to Covid parts availability, bike has had a new motor in Jan 2023 no mention of a software update on my receipt.
Just purchased full 10 speed shimano linkglide setup 11-43, thats going to fitted this weekend, that will hopefully last considerably longer.
 

I went through this process when I increased my chainring and modified my gear ratio.

In a nutshell, there is no firmware to be updated when changing your gear ratio. I presume you're already running firmware v1.1.5.0 which is the latest version, so no action here.

BUT, there are two Important parameters in your drive unit that store the max gear ratio and min gear ratio of your bike's drivetrain. These parameters are originally programmed by the manufacturer and can be updated by the bike shop (bosch dealer) using the bosch diagnostic tool.

Max and min gear ratio values are used by the motor to determine power delivery, bike speed, and could lead to errors if set incorrectly.

In your scenario, with a 11-50 cassette and let's say a 34T chainring as an example, your max gear ratio would be 34/11 (or 3.09) and your min gear ratio would be 34/50 (or 0.68). This would be the values currently stored in your drive unit.

When changing the cassette to 10-50, your new max gear ratio would become 34/10 (or 3.4) instead of 3.09. So, unless you update the max gear ratio in the drive unit to 3.4, your motor may not function correctly (efficiently) as far as power delivery is concerned. Your dealer/bike shop was correct. I would suggest having them update your max gear ratio in the drive unit after changing the cassette.

Hope this helps.
 
Last edited:

target2804

New Member
Apr 26, 2023
55
80
Germany
I didn’t know that a bike dealer can do that but if they can, I am sure they will.
Also: Haibike contacted me today and they told me that they asked one of their engineers and it is possible to change the cassette to 10-50. so the max gear ratio might be higher because they might sell bikes with 38/10 and do only have 1 software configuration.

I could still change the 38 to a 36 and see if this is within the limits. I will get the cassette replaced soon so let’s see what comes out.
 
@target2804 The dealer/bike shop can certainly provide you the Bosch Diagnostic report for your bike which will show the max and min gear ratio stored in your drive unit.

Knowing these ratio values, you could always try different combinations of chainings and cassettes to stay as close as possible to the stored values (if you decide not to change the stored values of course).

Hope my posts helped answer your questions.

Good luck!
 
Last edited:

target2804

New Member
Apr 26, 2023
55
80
Germany
@target2804 That makes sense. The dealer/bike shop can certainly provide you the Bosch Diagnostic report for your bike which will show the max and min gear ratio stored in your drive unit. Knowing these ratio values, you could always try different combinations of chainings and cassettes to stay as close as possible to the stored values. Good luck!
At the moment I guess it’s a 3.8 gear ratio in the software. My alltrail 8 in purple color has a sram 11-50 cassette. The alltrail 8 in red has a shimano 10-51 cassette. Both with the 38 in the front. Many other bikes do have a 10/38 combination with the Bosch motor. So I guess they do have 1 software for all the bikes. That’s why they told me it’s possible to change the cassette.
 
@target2804 Yes, if you already have a 38/10 (3.8) max gear ratio stored in your drive unit, you could definitely install a 10-50 cassette. The max gear ratio from the new cassette with 38T chainring would be 38/10 (3.8) matching exactly the stored value, so no software config change needed.

Only way to tell for sure what gear ratio values are stored in your motor is to have your bike shop print a bosch diagnostic report for you, or you watch over their shoulders as they connecf the bosch diagnostic tool to your Purion display. The values will be displayed on the computer screen.

However, if you don't have a max gear ratio of 38/10 (3.8) currently stored in your drive unit and install a 10-50 cassette, your motor may not function well from a power delivery standpoint and may generate errors.
 
Last edited:

darvd29

Member
Dec 17, 2022
23
16
Poland
@target2804 Yes, if you already have a 38/10 (3.8) max gear ratio stored in your drive unit, you could definitely install a 10-50 cassette. The max gear ratio from the new cassette with 38T chainring would be 38/10 (3.8) matching exactly the stored value, so no software config change needed.

Only way to tell for sure what gear ratio values are stored in your motor is to have your bike shop print a bosch diagnostic report for you, or you watch over their shoulders as they connecf the bosch diagnostic tool to your Purion display. The values will be displayed on the computer screen.

However, if you don't have a max gear ratio of 38/10 (3.8) currently stored in your drive unit and install a 10-50 cassette, your motor may not function well from a power delivery standpoint and may generate errors.
This would mean that the max/min gear ratio stored value do not have to exactly match the current gearing (e.g. 34t with 10-52 would give 3.4 and 0.65), but it can be set even larger/lower respectively? The point is not to match the settings in the drive unit to the actual gearing, but rather have the actual gearing within the max/min values? But if that was the case, what would be the point of having this setting at all? For me, logically, the stored values should exactly match the actual gear ratio, shouldn't they?
 

emtbPhil

Well-known member
Jun 20, 2021
408
452
UK
Exactly as stated - it's not a firmware change but it's variables stored for the motor program

If you change ratio's the motor see's how fast you are pedalling from motor RPM and see's wheel RPM from the magnet sensor - but they don't work out. So if you go too far out of whack it could just assume the wheel is spinning or something worse.

For piece of mind I'd update it - I noticed it when I was at the LBS and they couldn't do the firmware update so I did it myself with their laptop (no comment) - I had changed from a 36T chainring to a 32T chainring and there was an option to set that too.
 

For me, logically, the stored values should exactly match the actual gear ratio, shouldn't they?
Yes, as I mentioned earlier, the Min and Max Gear Ratio values stored in the drive unit must match the actual drive train gear ratio.

These 2 parameters in the BDU are not a "range", but discrete values. They need to be set to match the mofified drivetrain on the bike, that is if changes are made to cassette and/or chainring sizes.

Hope this helps.
 
The point is not to match the settings in the drive unit to the actual gearing, but rather have the actual gearing within the max/min values?
No, the gear ratio settings in the drive unit need to match the actual drivetrain. This is done originally by the bike manufacturer. Any subsequent gear ratio changes made to the actual drivetrain by the bike owner must be reflected in the drive unit via the bosch diagnostic software tool. Only bosch dealers have access to this software by the way.

Why? Because the Bosch motor uses the max gear ratio and min gear ratio values (among others) for efficient power delivery and speed calculation.
 
Last edited:

darvd29

Member
Dec 17, 2022
23
16
Poland
No, the gear ratio settings in the drive unit need to match the actual drivetrain. This is done originally by the bike manufacturer. Any subsequent gear ratio changes made to the actual drivetrain by the bike owner must be reflected in the drive unit via the bosch diagnostic software tool. Only bosch dealers have access to this software by the way.

Why? Because the Bosch motor uses the max gear ratio and min gear ratio values (among others) for efficient power delivery and speed calculation.
All clear now. Glad I came upon this thread as I’ve recently changed from original 11-50 cassette to 10-52. Definitely going to get this done ASAP! Thanks.
 

Bestak CZ

Member
Dec 26, 2021
7
0
Czechia
Bosch a Haibike říkají, že při výměně kazety potřebuji aktualizaci softwaru, protože motor je naprogramován na 11-50 na 38 ozubených kolech a jinak může dojít k chybám.

Dostanu takovou aktualizaci od svého prodejce kol? Nebo to musí nejprve vydat Haibike a to je zbytečně dlouhý proces?

Chci se konečně zbavit kazety PG-1210 a hned bych si koupil GX-1275, ale asi neumím řídit. (Rozkol mám vhodný s volnoběžkou XD, která se mi doma povaluje).
Hello, I have a Haibike XDuro 10.0 with a Flyon motor and I shift 9 /52, 10/51(52) or 11/52 tooth cassettes and 38,42,44 or 46 tooth derailleurs with or without Bikespeed acceleration and have never experienced any problem or error. It's basically the same as shifting different gears or changing pedaling frequency. I feel like the service department just wants to extract some more money out of you.
 
Last edited:

target2804

New Member
Apr 26, 2023
55
80
Germany
The Haibike engineers reached out to me and told me I can change the cassette. I can have a max of 52 teeth and a min of 10 with my 38 in the front. I had a quick research already on their website and found out that many bikes are using 38/10 or even 40/10 on trekking bikes. I assume that they only install 1 software package on their bikes with Bosch motor.

My bike dealer is an official Haibike reseller and I guess they can change anything to my needs. And they should be also allowed to because as I said: the other alltrail8 29 with the new smart system used 38-10 too. So there shouldn’t be any restriction for me.

But I heard that only Haibike can change the gear ratio. Some others say it can be done by the seller. So I am not 100% sure.
But i wouldn’t be surprised if they rather want to sell me a new bike with a good cassette than allowing me to change the 11-50 SRAM PG-1210 to a XG-1275 😂
 

Bestak CZ

Member
Dec 26, 2021
7
0
Czechia
Ano, jak jsem již zmínil, hodnoty Min a Max Gear Ratio uložené v pohonné jednotce musí odpovídat skutečnému převodovému poměru hnacího ústrojí.

Tyto 2 parametry v BDU nejsou "rozsah", ale diskrétní hodnoty. Musí být nastaveny tak, aby odpovídaly upravenému hnacímu ústrojí na motocyklu, to znamená, pokud jsou provedeny změny velikosti kazety a/nebo převodníku.

Snad to pomůže.

Yes, as I mentioned earlier, the Min and Max Gear Ratio values stored in the drive unit must match the actual drive train gear ratio.

These 2 parameters in the BDU are not a "range", but discrete values. They need to be set to match the mofified drivetrain on the bike, that is if changes are made to cassette and/or chainring sizes.

Hope this helps.
Hello, I'm no expert, but I don't think it's necessary to look for a big science in this. I change the 9,10,11/50,51,52 tooth cassettes and toothed plates from 38 to 46 teeth as I think of it and the maximum power of the TQ Flyon motor is still 950 W and 120 Nm. I have never experienced any error messages.
 

target2804

New Member
Apr 26, 2023
55
80
Germany
Just curious if you were able to get the bosch diagnostic tool report for your bike from the dealer and if so, what were the max and min gear ratio values showing in the report ?
I’ll tell you when everything is done. Wasn’t able to change anything on my bike yet. Parts are already there but… no time
 

darvd29

Member
Dec 17, 2022
23
16
Poland
No, the gear ratio settings in the drive unit need to match the actual drivetrain. This is done originally by the bike manufacturer. Any subsequent gear ratio changes made to the actual drivetrain by the bike owner must be reflected in the drive unit via the bosch diagnostic software tool. Only bosch dealers have access to this software by the way.

Why? Because the Bosch motor uses the max gear ratio and min gear ratio values (among others) for efficient power delivery and speed calculation.
So I visited my LBS with access to Bosch Diagnostic Software tool and they were not able to update the gear ratios. Unfortunately, the values are grayed out, read-only. Not sure what to do now :(

tempImageCFtoO7.png
 

darvd29

Member
Dec 17, 2022
23
16
Poland
It can only be provided by your maufacturer.
Oh no, that would be a real shame ☹️. It would seem that "overpaying" for bikes from well-known brands is not just paying for the logo, but for an actual customer service :) Trek LBS really wanted to help but they could not change the values. Actually it's weird, because they've performed firmware upgrades and printed out reports for me in the past without any problems.

The bike is a Stilus which is sold by Decathlon but manufactured by Lombardo in Italy. I just contacted my local Decathlon store and they say they do not have access to Bosch software, just the only one main service central in the country in a different city has the access. So I'd have to get the bike shipped to them and wait weeks or even months for such a simple change. And that is assuming Decathlon Poland would actually be able to change those values rather than having to ship it Lombardo Italy 🙃.

However, I've ridden with the new gear ratios for a few hundred kilometres without any problems with errors or feeling of the ride, so I'll just keep on riding it with wrong ratio saved in the motor, hopefully without any future problems.
 

Bestak CZ

Member
Dec 26, 2021
7
0
Czechia
Hello, I just want to reiterate what I've already written. I¨m no expert, but I don't think it's necessary to look for a big science in this. I change the 9,10,11/50,51,52 tooth cassettes and toothed plates from 38 to 46 teeth as I think of it and the maximum power of the TQ Flyon motor is still 950 W and 120 Nm. I have never experienced any error messages.
 
I checked as well. The bike manufacturer must first authorize the change to your gear ratio.

You will need to work with your bike shop to schedule a time for the bike manufacturer to connect to your bike remotely and download the changes needed to your bike motor e.g new gear ratio.

Any professional bosch dealer/LBS knows this procedure and should be able to assist you, and coordinate the change with the bike nanufacturer.
 

target2804

New Member
Apr 26, 2023
55
80
Germany
After a successful installation of all my new parts i can say: the motor didn´t care at all. But that is also because Haibike is selling bikes in many different variations of gear ratios going up to even 40-10. For the Bosch Motor they just have one config that they put on all their bikes i guess.

long story short: new cassette in, no update. motor doesnt care at all. The GX derailleur with the GX cassette and the XX1 chain work so well together. You can barely hear the shifts. It´s amazing. I am super happy :)
 

EMTB Forums

Since 2018

The World's largest electric mountain bike community.

560K
Messages
28,337
Members
Join Our Community

Latest articles


Top