SRAM AXS derailleur connected to main ebike battery

Shandor

New Member
Jan 5, 2022
8
7
Poland
Hello

I have upgraded my 21 Scott Stride eride with SRAM AXS electrically operated derailleur

I like the system (except controller paddle), but would like to upgrade it – replace the derailleurs battery with power supply from main ebike battery. SRAM has such option - the upper version of Scott Patron has these feature as a standard setup. The problem is that cannot find the part numbers of SRAM wire interface. The only what I have found


My Scott representative said that battery interface is a SRAM part (not Scott’s) and provided me the part number ( 00.3018.317.000.) but I cannot find it in the net, so either the part number is wrong or the system is so new.

Does anybody knows part number of the interface?

KR,
Shandor
 

Jackware

Fat-tyred Freakazoid
Subscriber
Oct 30, 2018
2,086
2,299
Lancashire
Why add cost and complexity to the system, the battery lasts a long while, is easy to swap out and takes very little time to charge?
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,583
5,062
Coquitlam, BC
E-derailer, E-dropper, E-forks, E-shock, and E-brakes. That’s a lot of batteries. (Oh, and the main battery).
Sram wireless is pretty fast and I have to say that I love the wireless derailer (with Shimano HG cassette and chain). Even though I’m still waiting for the AXS reverb, E-brakes are in my sights. Flight Control?
Maybe a main-battery wired system is the answer?
 

highpeakrider

E*POWAH Master
Aug 10, 2018
693
566
Peak District
E-derailer, E-dropper, E-forks, E-shock, and E-brakes. That’s a lot of batteries. (Oh, and the main battery).
Sram wireless is pretty fast and I have to say that I love the wireless derailer (with Shimano HG cassette and chain). Even though I’m still waiting for the AXS reverb, E-brakes are in my sights. Flight Control?
Maybe a main-battery wired system is the answer?

So are you running a mix of SRAM and Shimano?
 

RustyIron

E*POWAH Elite World Champion
Subscriber
Jun 5, 2021
1,842
2,881
La Habra, California
I like the system (except controller paddle), but would like to upgrade it – replace the derailleurs battery with power supply from main ebike battery. SRAM has such option

That sounds like a sensible progression of the "electronic bicycle" concept. Surely as electronic shifting becomes more mainstream, discrete power sources will become a thing of the past. My only question is, once you get the adapter, where will you pick up the correct voltage for the derailleur? I don't know what voltages all the different contraptions require, but I'm a bit familiar with building systems where all the components have different requirements and no one ever thought about how to make it all work. That might be the biggest challenge.

On a lesser note, you might want to try the "paddle upgrade." I went back and forth between the "original" and the "upgrade." Eventually I settled on the "upgrade," rotated really low and pushed inboard. Honestly, I don't know why all the pictures in the online reviews have the cockpits looking like they were set up for Tyrion Lannister.
 

randycpu

Member
Nov 15, 2018
103
45
Silicon Valley, USA
does sound a bit like finding a problem to solve tbh. Just keep a charged spare battery in your ride pack and check them every 3 months or so or if you haven't used the month for a while.
Yes. This is what I do, rotating the packs every two weeks when I charge my Garmin...

And the derailleur likely runs on typical Li-Ion 3.7 volts nominal. To have a central power source you would need a DC to DC converter.
 

nontas

Member
Dec 9, 2022
2
3
Greece - Agrinio
Trek released a factory edition for that purpose

FB_IMG_1681911311673.jpg
 

BigG

Active member
Feb 15, 2023
90
100
US, SoCal
Has anyone tried asking a trek dealer what part enables all that (mech powered with ebike battery via wire)?
I know some trek online dealers sell a cable that connects derailleur to so called AXS smart box, but it looks to be TQ/EXE specific.
If possible I would like to simply get whatever trek created for bosch/axs bikes and hopefully fit on non-trek bike with bosch motor.
My local trek dealer experience was quite bad before, but I’ll ask them sometime myself, little to no hope they’ll help though.
 

Sander23

Active member
Aug 28, 2020
740
457
Belgium
Has anyone tried asking a trek dealer what part enables all that (mech powered with ebike battery via wire)?
I know some trek online dealers sell a cable that connects derailleur to so called AXS smart box, but it looks to be TQ/EXE specific.
If possible I would like to simply get whatever trek created for bosch/axs bikes and hopefully fit on non-trek bike with bosch motor.
My local trek dealer experience was quite bad before, but I’ll ask them sometime myself, little to no hope they’ll help though.
The cable also exist for bosch. You need to connect it to a bosch light cable.

Don't know how it connect to the derailleur though
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,583
5,062
Coquitlam, BC
Has anyone tried asking a trek dealer what part enables all that …
I don’t think there would be a market for this. I installed the axs GX derailer to lessen the amount of cables/wires running through my bike. Soon after I ordered and installed the AXS reverb dropper (170mm) on my medium sized Rail. Noticeable improvement there too.

I’ve never killed the AXS battery on either of these Sram wireless systems. I charge both batteries once a week after 5-6 rides, 15km to 30km per ride. There is a LED red indicator light on each device that indicates that the batteries are low. Charging is fast also (20 min?).

I don’t have wireless-anxiety because I ride with two batteries, one on the derailer and one on the dropper. The AXS Reverb dropper is an expensive luxury IMO, but it’s really nice.

I’d have second thoughts on the Sram Flight Attendant system though.
 

indie1982

Member
Apr 16, 2021
7
2
The Hills
This may (or may not) help, I asked SRAM about the cord that's listed in the AXS manual.
Keen eye! I believe you are seeing the OE-only AXS extension cord for Bosch motors, which allows your derailleur to be powered off of the e-bike battery. Unfortunately, this is not available for aftermarket purchase as it is a feature that has to be hardlined into the bike from the factory. As such, the only way to get this would be to purchase a bike that comes stock featuring this part.
It's a shame they don't sell them to end users, they're missing a trick!
 

JuSiZ

Member
May 16, 2023
11
9
Finland
This may (or may not) help, I asked SRAM about the cord that's listed in the AXS manual.

It's a shame they don't sell them to end users, they're missing a trick!
I think trek must sell this part for customers if someone broke it. Does someone know trek partnumber to that part what goes in derailleurs battery slot?
 

gorbypark

New Member
Jul 12, 2023
1
0
Canada/Spain
The hacker in me thinks this shouldn't be too hard to make work. A quick search seems to show that Gen4 Bosch motors have a 12v output for lighting. If your bike didn't come with a light, the feature needs to be enabled in the firmware by a dealer (or someone with the Bosch diagnostic software/hardware). It seems to be easy to find a Bosch lighting cable with the proper connector to connect to the motor.

The AXS system seems to be 7.4v nominal, so there's a very good chance that 12v will be too much for it (although not necessarily, 7.4v nominal batteries are around 8.4v when fully charged...).

I think the way to go would be to buy a lighting cable and an extra battery and remove the battery cell from the battery housing. If someone would take the chance to guinea pig running the derailleur at 12v, you could just hook up the cable to the connection pins in the now hollowed out battery housing and hope you don't get any magic smoke!

However, there would probably also be enough space in the empty housing to get a 12v to 7.4v buck converted to drop down the voltage. Those are a dime a dozen on AliExpress.

The only real issue would be if there is some sort of fancy stuff going on between the derailleur and the battery. Most likely there's not, but you never know these days if they're communicating together (maybe as a type of DRM to try and thwart 3rd party batteries?).
 

JuSiZ

Member
May 16, 2023
11
9
Finland
The hacker in me thinks this shouldn't be too hard to make work. A quick search seems to show that Gen4 Bosch motors have a 12v output for lighting. If your bike didn't come with a light, the feature needs to be enabled in the firmware by a dealer (or someone with the Bosch diagnostic software/hardware). It seems to be easy to find a Bosch lighting cable with the proper connector to connect to the motor.

The AXS system seems to be 7.4v nominal, so there's a very good chance that 12v will be too much for it (although not necessarily, 7.4v nominal batteries are around 8.4v when fully charged...).

I think the way to go would be to buy a lighting cable and an extra battery and remove the battery cell from the battery housing. If someone would take the chance to guinea pig running the derailleur at 12v, you could just hook up the cable to the connection pins in the now hollowed out battery housing and hope you don't get any magic smoke!

However, there would probably also be enough space in the empty housing to get a 12v to 7.4v buck converted to drop down the voltage. Those are a dime a dozen on AliExpress.

The only real issue would be if there is some sort of fancy stuff going on between the derailleur and the battery. Most likely there's not, but you never know these days if they're communicating together (maybe as a type of DRM to try and thwart 3rd party batteries?).
Yep. That is what i think to do if not get sram oe part anywhere. Some kind little battery or capacitor is in oe part because it works some time if you run bike battery empty.
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,583
5,062
Coquitlam, BC
It is on the Trek Rail 9

Rail9GXAXS_23_36992_A_Alt9
In the picture you posted of the new AXS GX mounted on the Trek Rail 9…what is the cable housing for? It seems to exit the chain stay and enters the AXS GX derailer. I wonder what the purpose of that is?

Edit: Ah, never mind. Auxiliary power to the GX. (I should have read previous posts).
 
Last edited:

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,583
5,062
Coquitlam, BC
Looks like the power cord for AXS is pictured in the exploded view in the post below.

Post in thread 'Official Specialized Gen 3 2022 Levo Megathread!'
Levo Gen 3 - Official Specialized Gen 3 2022 Levo Megathread!
I wonder if that’s a mock-up or photoshop (in your original post), or if it’s an actual working add-on? ( I couldn’t link to the Levo Gen3).

The lighting socket is slightly different between new and older Bosch gen4. Found that out when I tried to insert plugs into the vacant socket.
 

Send_it

New Member
Jul 29, 2023
8
3
Sussex
I wonder if that’s a mock-up or photoshop (in your original post), or if it’s an actual working add-on? ( I couldn’t link to the Levo Gen3).

The lighting socket is slightly different between new and older Bosch gen4. Found that out when I tried to insert plugs into the vacant socket.
it is from a photo on the UK Trek site. Not mentioned in all of the write up about the bike.


1691523014051.png
 

JC-1

Member
Aug 23, 2021
68
17
New Zealand
My Rail came with this, but I've replaced the AXS non-T-Type with GX T-Type which tucks the battery away differently to the XX/XO derailleurs. Unfortunately, the wired dummy battery can't be used. I'm hoping there's another version in the works that will suit GX.
 

Aug 17, 2022
20
6
Dijon
Mise à jour : SRAM a déclaré qu'il n'envisageait pas d'introduire une batterie filaire compatible GX T-Type.
Bizarre, dans le manuel utilisateur AXS 2023 en page 11, il y a ce message :
Et dans le second manuel "eagle-transmission-frame-fit-specifications", en page 14, il y a la référence pour moteur Bosch Gen4 Smart System. Mais je ne le trouve pas !
câble.jpg cable bosch pour axs.jpg
 

EMTB Forums

Since 2018

The World's largest electric mountain bike community.

556K
Messages
28,081
Members
Join Our Community

Latest articles


Top