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Sram Eagle Powertrain: Industry Icon Makes a Real Statement

Sram Eagle Powertrain ebike drive

First it was just a rumour. Now comes confirmation. As of today, one of the biggest names in the bicycle industry, Sram, is returning as a manufacturer of an own ebike system. The new drive of the cult brand from Chicago is called Sram Eagle Powertrain.

Components of the Sram Eagle Powertrain ebike drive shown as a system
All components of the Sram Eagle Powertrain

Before we go into more detail about the new product, let’s take a brief look back. At the beginning of 2022, there were first signs that Sram could possibly develop an own drive. At that time, the manufacturer registered its own racing team for the E-Enduro World Series. Its official name was “BlackBox Test Pilot Program”. The majority of the international media suspected that the project could conceal work on a complete ebike system. In the past, the manufacturer had already brought two systems onto the market with the rear hub motors “Sparc” and “E-Matic”. However, both failed to establish themselves in the long term and were shelved after some time.

From our point of view, the Sram Eagle Powertrain should be spared this fate. It is too technically mature for that, is supported by a too knowledgeable cooperation partner and has already completed too many test kilometres too well. Above all, however, the manufacturer is not starting from scratch. In the Eagle Powertrain, Sram’s know-how from mountain biking, its wireless AXS technology and the Eagle Transmission groupset bring together so many proven factors that failure seems impossible. For you, we’ll take a closer look at the above-mentioned points and at the end we’ll focus on the components that are actually new.

Key Sram technologies combined in the Sram Eagle Powertrain ebike drive
The drive combines several key technologies from Sram.

1. Factor mountain biking: data, triumphs and first users
2. Factor AXS technology: completely remote-controlled
3. Factor Eagle Transmission: shifting performance on a new level
4. Sram Eagle Powertrain – the motor
5. Sram Eagle Powertrain – the batteries
6. Sram Eagle Powertrain – upcoming bikes

1. Factor mountain biking: data, triumphs and first users

Some tasks become easier when they are broken down to the essentials. Sram has also followed this route. The new ebike system is a drive with a mid-mounted motor that is clearly geared towards use on e-mountain bikes. And this is precisely the field in which Sram has been working on the development. So a powerful team was put together for the 2022 season in the Enduro World Series for ebikes (EWS-E), an outstanding rider was signed up in the form of Yannick Pontal – and the wild chase began. For points, of course. But above all for data, for confirmation, for mistakes and whatever else you’re looking for when you set up such a drive and try it out on the race track under real conditions in parallel to the work in the lab.

Motif from the development phase of the Sram Eagle Powertrain ebike drive
After racing events such as in the E-EWS, a comprehensive analysis of the recorded data was carried out during development.

This way, a lot of input comes back to the development team. And it looks like the engineers have successfully interpreted and steadily implemented it. In the end, Yannick Pontal actually took the overall victory. Probably even more important for Sram is that after an extremely short development phase, a ready-to-ride system can be presented today. In a press release, it says that they have transferred the experiences of professional athletes to the expectations of “normal” people. “Our focus is always on the rider first,” says Michael Hemme, E-MTB Category Manager at Sram. ” The goal of the system was to provide the rider with a complete, wireless, integrated E-MTB system tuned specifically for performance mountain biking. We simplified the ride allowing the rider to focus on the trail.”

Yannick Pontal presents the trophy for his overall victory at the E-EWS 2022
Still under the mantle of the BlackBox Test Pilot Program, Yannick Pontal took the overall victory in the E-EWS in the 2022 season.

This year, Sram has an official factory team racing in the UCI Mountain Bike Enduro World Cup for ebikes (EDR-E), as the successor to the EWS-E is now known. In addition, teams Gasgas SRAM Racing, Gasgas Motorex Racing and Nukeproof-SRAM Factory Racing will start with the Eagle Powertrain.

2. Factor AXS technology: completely remote-controlled

What you look for in vain on an e-mountain bike with the Sram Eagle Powertrain are cables. Ok, there are the brake lines, we still can’t get around those these days. But apart from that, there is a total lack of cables. The reason for this is not cables skilfully hidden in the frame. They simply don’t exist. Gearing, seatpost, suspension – everything works wirelessly via Bluetooth. Provided that the bicycle manufacturer uses the complete product range from the Sram brand universe. This means first and foremost Rockshox’s Flight Attendant electronic suspension and the Rockshox Reverb AXS seatpost.

Sram Eagle Powertrain ebike drive control pods
Sram Eagle Powertrain control pods

On the handlebars we encounter the familiar AXS Control Pods. With their help, you can control everything on the ebike that can be operated in this way. The system is designed so that you use both pods. There are two buttons on both the left and right pods. Depending on whether you press them for a short or long time, they trigger different actions. These are the factory default settings:

Long button press

  • Top left pod: walk assist
  • Button left pod down: seatpost
  • Top right pod: Auto Shift on / off
  • Button right pod: setting cadence setpoint for Auto Shift

Short button press

  • Top left pod: changing ride mode
  • Button left pod: seatpost
  • Top right pod: shifting gear up
  • Button right pod: shifting gear down

If this configuration does not suit you, you can change it using the AXS app. The only thing that cannot be changed is the walk assist. It always remains accessible on the upper button of the left pod via a long button press.

Nerve centre in the top tube

Sram has generally not designed a display on the handlebars. However, you are by no means solely dependent on the screens of the app on your smartphone. The AXS Bridge Display is integrated into the top tube. This is also rather minimalistic and offers a manageable amount of information. You can always see the currently selected riding mode, your setting with regard to the Auto Shift function and a percentage indication of the remaining battery charge.

Those who would like to get more information while riding can use the ANT+ interface of the display. This can be used to connect bike computers from Garmin, Wahoo, Hammerhead and others, as well as a smartwatch. On these devices, you can see a lot of additional data, such as speed, cadence and your power output in watts.

Needless to say, the display is protected against water, dust and other environmental influences. If you should receive a knock on it, Gorilla glass will hopefully ensure that it survives this undamaged.

AXS Bridge display for Sram Eagle Powertrain ebike drive that can be integrated into the top tube
Simple screens characterise the AXS Bridge display that can be integrated into the top tube.

In addition to the on/off button at the top, the display has a second button at the bottom with the AXS symbol on it. Both are pre-assigned as follows:

On-Off button

  • Short button press: service mode / switch off motor support
  • Long button press: switch on or off

AXS button

  • Short button press: change riding mode
  • Long button press: start or end pairing with components

No analysis without app

Sram obviously takes its intention very seriously not to distract you with too many displays and information while riding. This is probably also the reason for the decision to go without a display on the handlebars, for example. If you want to call up comprehensive data and statistics, you have to use the AXS app. Here you can see the following information, for example:

  • Remaining battery charge
  • Number of charging cycles
  • Kilometres travelled
  • AXS components currently connected to the display
  • Charge status of the components
  • Temperature of the components
  • Model
  • Serial number
  • Hardware and firmware versions
  • Availability of new firmware
  • Diagnostics and error messages

In addition, certain settings such as the riding modes can be individualised there. Unfortunately, we cannot yet tell you how exactly this works. This is not clear from the information provided by Sram. In addition, we have not yet had a bike with this drive in our hands.

3. Factor Eagle Transmission: shifting performance on a new level

If there is one area in which Sram has enormous expertise, it is in gear shifting. Therefore, the Eagle Powertrain of course includes a groupset from its own company. Fortunately, with the Eagle Transmission, it is the most advanced derailleur that the manufacturer can currently offer. The system without derailleur hanger was only introduced in spring. Now it is becoming one of the central components for the ebike system.

Transmission rear derailleur for the Sram Eagle Powertrain ebike drive
Version of the transmission rear derailleur for use on the ebike

For use on e-mountain bikes, Eagle Transmission even features two completely new additional functions. The first is called Auto Shift. Some of you will already know the principle of this from the eShift function of the Bosch drives, for example for Enviolo hub gears. Both Sram and Bosch follow the same basic idea. You enter your preferred cadence into the system and the ebike drive does the necessary gear shifting. Only Auto Shift does this with derailleur gears.

Sram lets you choose between a total of seven different levels and hopes that at least one of them comes as close as possible to your personal riding style.

Breaking with old conventions

Those who find this already amazing will look even more incredulous at the second function. For Eagle Powertrain, it doesn’t matter whether you are actively pedalling or coasting – the system will change gears at any time. Coast Shift shifts up or down, just as the riding situation demands. To do this, Sram decouples the chainring and cranks to a certain extent so that they can rotate independently of each other.

Both shifting functions, Auto Shift and Coaster Shift, are used exclusively by Sram on the Eagle Powertrain. As soon as a bicycle manufacturer turns to another manufacturer for the shifting, these options are lost. Not a bad move to “convince” bicycle brands of the new system. 😉

4. Sram Eagle Powertrain – the motor

Given the listed innovations, it seems understandable that Sram relies on a proven source for the motor instead of trying to do everything themselves. The Americans have teamed up with Brose. If we interpret the pictures correctly, the Brose S Mag comes from there. Sram equips it with its own software that corresponds to its own ideas of an e-mountain bike. The approach is similar to the cooperation that for example Yamaha and Giant have been successfully practising for years with the SyncDrive motors.

Sram Eagle Powertrain ebike drive motor
With a maximum torque of 90 Newton metres, the mid-mounted motor is one of the most powerful on the market.

This means that the motor’s performance data is no complete surprise. The 2.9-kilogram unit generates a maximum torque of 90 Newton metres and thus definitely belongs to the full-power category. Due to the tuning, characteristics such as the response, the power delivery, the maximum support, the noise level or even the temperature management may well differ compared to the original from Brose. The first test reports will certainly provide information on this soon.

Sram Eagle Powertrain motor

  • Rated continuous power: 250 W
  • Maximum power: 680 W
  • Torque: up to 90 Nm
  • Weight: 2.9 kg
  • Motor assistance: up to 25 km/h
  • Rated voltage: 36 V
Sram Eagle Powertrain ebike drive motor
For the motor, Sram has cooperated with the German manufacturer Brose.

The drive includes a speed sensor called Speed Ring. It contains several magnets. This is supposed to provide a higher resolution speed signal, which in the end leads to fast and precise automatic shifting.

Speed sensor for the Sram Eagle Powertrain ebike drive
In order to measure as accurately as possible, the speed sensor features several magnets.

Modest duo

You can use the motor in two riding modes. That’s right, two. Usually, other e-drives offer three to five different support levels. Sram deliberately sets itself apart from the competition here. According to Sram, Range Mode and Rally Mode are designed to reduce unnecessary complexity through simplicity. You have probably already guessed from the name that in Range Mode everything is designed for the longest possible range. Sram recommends this mode for longer tours with less metres of elevation gain. If, on the other hand, you don’t want to hold anything back and want to be pushed forward to the maximum at all times, then it absolutely has to be Rally Mode.

On paper, this looks like a classic black-and-white pattern that demands either/or decisions from you. But it doesn’t have to be quite so extreme. After all, the modes can be changed via the app so that you can make them a little less contrasting and make room for grey. Nevertheless, it will be exciting to see how the response to this aspect of the e-drive turns out.

Range and Rally riding modes on the Sram Eagle Powertrain ebike drive
In the AXS app you can adjust the two riding modes Range and Rally to your preferences.

5. Sram Eagle Powertrain – the batteries

We don’t know if the batteries are the result of a collaboration or if they were developed entirely by Sram. What we do know is that the system includes a total of three different batteries. Two for use in the down tube and one as an additional battery to increase the range. Of the two main batteries, the one with the lower capacity can be removed from the down tube. Sram refers to this as a C-shaped mount. This allows you to remove the battery from the side or upwards. Depending on how the respective bike manufacturer implements this. GasGas and Propain will offer such solutions.

Pictures of this are apparently not yet available. Neither is there an estimate of how many kilometres with electric support the 630 watt hours of capacity might be enough for. With a weight of only 3.1 kilograms, it is almost 800 grams less than the model with the same capacity shown on the Brose website. Once completely discharged, it should be recharged within four and a half hours with the accompanying 4 A charger.

Sram Eagle Powertrain battery 630 Wh

  • Capacity: 630 Wh
  • Weight: 3.1 kg
  • Cell type: 21700
  • Charging time: 4.5 h
Sram Eagle Powertrain ebike drive battery

The process does not take much longer with the second intube battery. After five hours on the grid, it has regained its original capacity of 720 watt-hours. It weighs 4.1 kilograms and is slid into the down tube from below. According to Sram, Nukeproof will offer models where the battery can also be removed. Transition, on the other hand, will install it permanently.

Sram Eagle Powertrain battery 720 Wh

  • Capacity: 720 Wh
  • Weight: 4.1 kg
  • Cell type: 21700
  • Charging time: 5 h
Sram Eagle Powertrain ebike drive battery

Should you run down one of the two batteries completely during the ride and have no way to recharge it, each battery will at least provide enough energy to power the lights and the gearing system for at least two hours.

You’ll be lucky if you can pull the range extender out of a bag or backpack at that moment. With it, you have another 250 watt-hours at your disposal in one fell swoop. It is held by a mounting plate on the down tube. If you screw an adapter onto it, you can also place a water bottle there.

Sram Eagle Powertrain Range Extender

  • Capacity: 250 Wh
  • Weight: n.a.
  • Charging time: 2 h

If you start with the Range Extender on your bike, it will be discharged first. At least as long as you ride in Range Mode. If you switch to Rally Mode, energy goes out of the main battery first. In contrast to the rest of the system, the range extender – individually or as part of a corresponding adapter kit – will not be available until November 2023.

6. Sram Eagle Powertrain – upcoming bikes

When exactly we will see the first e-mountain bikes with the complete Sram Eagle Powertrain is not clear from the information provided by Sram. The names of the brands you can expect have already been mentioned in the text. The following four manufacturers will soon present models featuring the drive:

  • GasGas
  • Nukeproof
  • Propain
  • Transition

Pictures: SRAM Germany GmbH

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