Sram eTap AXS 12 Speed Q&A

Posted by Alder Martz on 1st Mar 2019

Sram eTap AXS 12 Speed Q&A

A couple weeks ago on our social media accounts, we asked you what questions you have about Sram's latest eTap 12 Speed groupset. Here are the answers to the most common ones.

What's the deal with strange SRAM eTap 12spd gear ratios?

It is the gear ratios, not the addition of a 12th sprocket, that sets eTap AXS apart from everything else currently on the market and is forcing everyone to rethink the standard 53-39 x 11-25 we have to come to accept. Sram's new gear ratios, like a 50-37 x 10-26 produces a wider range at both ends as well as more 1t jumps between shifts. This means you are more likely to find that 'perfect' gear. 

Can I use my 11sp Freehub with the SRAM eTap AXS 12spd cassette?

Long story short, no. In order to fit a smaller 10T cog on a freehub, Sram designed their own freehub body, called “XDR Driver”. Many wheel brands have created XDR freehub bodies to retrofit their rear wheel and hub models. So if your current wheel’s manufacturer has a convert kit to XDR, it is possible to use eTap AXS without buying new wheels.

What wheels are compatible wheels with SRAM eTap AXS 12sp?

Shimano is just about the only wheel company that does not offer XD-compatible drivers for their hubs. We have a number of XDR Driver freehub conversion kits listed on the site here. If you don't see the one you need, send us an email

Can you mix new SRAM eTap AXS 12spd with the older 11sp

In general, no. AXS labeled devices only communicate with other AXS labeled devices. This allows a lot of customization between them through the AXS app, as well as mixing Eagle AXS and eTap AXS components.

The new chain, which is narrower, lighter, and stronger than the previous generation, is only compatible with the 12 speed XG-1290 cassette. Mixing components might work initially but will lead to suboptimal performance and potentially damaging components.

Its not all bad news though! Your eTap batteries and chargers will work across generations and rim brakes will work cross-generations.

What's the story about replacing the chainrings/powermeter on the AXS crankset?

Sram’s 2x AXS cranksets use direct mount chainrings that fasten to the crank arms for a stiffer, lighter, more precise crank. Yes, when the chainrings wear out, you will have to replace the integrated chainrings and power meter. However, Sram claims the chainrings will last 50% longer. That and regular maintenance will help extend the life of your rings. When the time comes to replace your chainrings, Sram will offer a half price replacement and will recycle the old one.

Sram’s 1x 48 and 50T variants also use integrated power meter and chainrings. However, the 36-48T cranksets use spider based power, like previous generation Quarqs.

What is the bottom bracket format for SRAM eTap AXS 12sp?

Sram is offering their cranksets with two variations for bottom brackets, GXP and their proprietary BB, Dub. The Dub system is compatible with most popular bottom bracket sizes, except for a few like BB90. Although, 3rd party companies might be quick to fill any gaps Sram didn’t.

Does the SRAM eTap AXS 12 Speed rear derailleur have a clutch?

Yes! All eTap AXS derailleurs come with a hydraulic clutch called Orbit. It is speed sensitive so only high speed cage rotations created by bumps tugging on the chain will activate the clutch mechanism. Think of it like a fluid trainer - the more movement, the greater the resistance. Since the clutch is movement activated, this creates an easier removal of the rear wheel.

Is there a WiFli rear derailleur option?

There is no WiFli option because there is no need for it. The eTap AXS rear derailleur can be paired with a max 33 tooth cog and has a total drivetrain tooth capacity of 36. (Drivetrain tooth capacity is calculated using the diffference in tooth numbers between the smallest and largest chainring + the difference between tooth numbers between the smallest and largest cog on the cassette).

If you wanted to use a larger cassette, the AXS system allows compatibility with AXS Eagle. So you could pair an Eagle rear mech with a 10-50T cassette and use eTap AXS shifters to control it all. In fact, in this setup, the unused front derailleur double shift could be modified in the AXS app to control something else, like an AXS dropper seatpost.

Can I use SRAM eTap with a 1 x crank

Yes! Sram makes 1x cranksets for eTap AXS. From 36T for cross/gravel, all the way up to 50T for road/gravel. If you want to use a third party 1x crankset, we would suggest waiting until they offer a 12 speed specific chainring that will work with Sram’s flattop 12 speed chain.

What is a direct mount chainring and crank?

Direct mount chainrings are like centerlock disc brakes where spidered are like 6-bolt. Rim brake user? Direct mount chainrings fasten to the crank arm in one spot, as opposed to spidered, which use 3-5 bolts to secure the chain rings to the crank. Direct mount chainrings systems are lighter and stiffer. Until now, direct mount has been reserved for 1x drivetrains, but Sram’s 2x direct mount chainrings represent direct mounts first foray into the 2x world.

What is the overall weight for the groupset?

2x Red Disc groupset is 2,518 grams. A power meter ads an extra 36 grams. The same groupset with rim brakes weighs 2,254 grams. For 1x, its 2,103 grams and 2,070 grams, respectively.

When will rim brake come out?

Rim brakes are available now! The rim brakes have remained mostly unchanged, with the main difference in that it can comfortably fit a 28 mm tire.

When will eTap Force be introduced?

Force eTap is coming in April. There isn’t a lot of details yet so we will have to wait and see how much technology from the Red eTap AXS will transfer to the Force groupset.

How much does the crankset weigh?

Below is a complete chart of the different weights for each component (as reported by

Red eTap AXS Shifter Set (with batteries)467 grams
Updated Blip Box24 grams
Road 2x Crankset (48/35) w/ powermeter               575 grams
Road 1x Crankset (48t) w/ powermeter551 grams
Front Derailleur165 grams
Rear Derailleur247 grams
Cassette (10-33)211 grams
Rear brake caliper (with housing)158 grams
160mm rotor118 grams

Youtube groupset review below.

Our eTap AXS 12 speed 2x listing is here and the 1x listing is here.

If you have any more questions, feel free to send us an email