Shimano Dura-Ace Di2 vs. SRAM RED AXS (12spd): Which Is Better?

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This article compares two high-end electronic road bike groupsets: Shimano Dura-Ace Di2 and SRAM RED AXS. I recently tried SRAM’s RED AXS (2019) and compared my experience with Shimano Di2. I’ll share my insights with you in this article.

Below, I will discuss deeper key factors such as shifting, braking, ergonomics, and more to help you decide between the two groupsets.

Abbreviations used: FD – front derailleur, RD – rear derailleur

Shimano Dura-Ace Di2 vs. SRAM RED AXS: Summary

The following table summarizes the most important features of these two groupsets.

Pros and Cons

Let’s now take a look at their pros and cons.

Shifting

Shifting is the most critical function of cycling groupsets. The first distinction lies in the shifting system. Shimano Di2 features two buttons on each lever. The left lever controls the front derailleur, while the right lever operates the rear derailleur. Dura-Ace Di2 also includes one hidden button on the top of each lever (unlike Shimano 105 Di2).

You might also be interested in this comparison of Shimano Dura-Ace vs. Ultegra vs. 105 Di2.

SRAM takes a different approach to shifting, making it more straightforward. Each shifter has only one button. To shift the front derailleur, you press both buttons simultaneously. Shifting the rear gears involves pressing either the left or right button. The 2024 version also has “bonus” buttons, which are programmable, so you can use them like D-Fly buttons on Dura-Ace.

Each groupset has its fans. I suggest trying both to see which one suits you better. Personally, I’m used to Shimano, but I find SRAM to be more intuitive.

Let’s turn our attention to shifting speed for a moment. Both groups have comparable performance in this regard.

However, SRAM 2019 front derailleur shifting proved less reliable, but early reviews of SRAM 2024 suggest that it matched Shimano.

Winner: It’s a draw

Electronics

A significant difference between Dura-Ace Di2 and RED AXS lies in their wiring: Dura-Ace Di2 is semi-wireless, while RED AXS is entirely wireless.

For Dura-Ace, cables run from the hidden battery (inside the seatpost) to the front and rear derailleurs. No cables connect the shift levers to the battery because they have a CR1632 battery inside.

On the other hand, SRAM’s system is fully wireless. The shifters and the front and rear derailleurs have their own batteries. The battery between derailleurs is even swappable and compatible with other SRAM road groupsets like Force or Rival.

The wireless groupset provides an advantage, particularly for those who want to build their own bike, as installation becomes easier.

Winner: SRAM

Gear Range

We’ve been used to “standard” gears on road bikes for a long time. However, as the picture below shows, SRAM has changed the game with its X-range gearing.

In fact, it was designed so you don’t need to shift the front chainring as often. SRAM achieved this by making it smaller while increasing the cassette’s gear range.

Winner: SRAM

Weight

The Shimano Dura-Ace Di2 (R9250) weighs approximately 2438g. The SRAM RED 2024 groupset is lighter than its predecessor, weighing around 2400g. However, the weight difference probably should not decide which groupset you purchase.

Winner: SRAM

Design

The overall design impacts functionality and aerodynamics, but I’ll leave that discussion to engineers. I’ll focus solely on appearance.

Personally, I’m more attracted to RED. Dura-Ace looks good, too, but I think the previous generations were sleeker.

Which one do you prefer?

Winner: It’s a draw

Ergonomics

Ergonomics is crucial to me. Having shifters that fit comfortably in my hands during long rides helps prevent discomfort (and potential blisters) and enhances the overall riding experience.

The SRAM RED 2019 had pretty bulky levers, but the SRAM RED 2024 ones are a bit prolonged and less bulky.

The position of the programmable buttons is more intuitive on Shimano, so for me, Shimano is the clear winner.

Winner: Shimano

Braking

The braking experience is quite similar for both groupsets, unlike mountain bike groupsets, where the braking effect varies slightly.

Unfortunately, I haven’t had the chance to test both sets side by side, and I haven’t found a comprehensive braking test.

However, you can expect similar braking performance based on the SRAM Rival AXS and Shimano 105 Di2 test results.

Winner: It’s a draw

Extras

Satellite shifters are valuable accessories for climbers or time trialists, as they eliminate the need to move your hand to change gears. Unlike the Shimano 105 Di2, the Shimano Dura-Ace Di2 supports satellite shifters because it has an accessory port.

SRAM RED also has this port (unlike Force and Rival), so satellite shifters can be easily connected to it.

Both groupsets have Bluetooth and smartphone connectivity. However, SRAM’s smartphone app is more user-friendly and delivers more information than Shimano’s.

As a result, if you’re interested in tracking the miles ridden on each gear or want to quickly reconfigure the buttons, SRAM is the better choice.

Both groupsets are also available with a power meter. However, Shimano power meters, unlike Quarq power meters found on SRAM groupsets, don’t have the best reputation. For this reason, I recommend using one of these reliable power meters with the Shimano groupset.

Winner: SRAM

Price

SRAM has an advantage in terms of cost. The Shimano Dura-Ace R9250 is priced at an incredible $4500 (excluding a power meter). At this price range, you can buy a pretty good road bike.

While the previous SRAM RED AXS was available for around $2400, the 2024 version costs ~$4100 without a power meter and ~$4600 with a power meter. However, it also includes a Hammerhead Karoo 3 bike computer, which costs $499 when bought alone. That’s a significant price bump.

Winner: SRAM

Total Score: Shimano (1), SRAM (5), It’s a draw (3)

Conclusion

Based on early reviews, the SRAM RED AXS 2024 seems to have matched Shimano in front of DR shifting and offers the same, maybe even better value.

However, it’s a matter of preference. I recommend trying both groupsets and then deciding which one suits you more.

Which of these two groupsets appeals to you more? Do you prefer Shimano or SRAM? Let me know in the comments.

Shimano Dura-Ace Di2 vs. SRAM RED AXS: FAQ