Since forever, the drivetrain market has always been something of an arms race. Originally it was all about seeing who could fit the most number of gears on a mountain bike. Then it became about who could put less chainrings on. And now that we’ve largely settled on 1X systems, the race has been on to see who can provide the biggest range.

SRAM put range on the map back in 2012 with the first XX1 11-speed drivetrain and its 10-42T cassette, which delivered a 420% gear range. It then pushed further with the release of Eagle 12-speed in 2016, which boasted an even bigger 500% range thanks to that huge 10-50T cassette. Shimano finally hit back when it unveiled 12-speed XTR, which offered a 510% range thanks to a highly amusing 10-51T cassette ratio that literally one-upped its American competitor by a single tooth. Ooh feisty!

Well, SRAM has decided to return the favour with the announcement today of a new 10-52T cassette. Take that Shimano!

SRAM Eagle Expands To 520%

Yep, SRAM’s 1×12 Eagle drivetrains have been updated with a new 10-52T cassette ratio that boosts total range to 520%. The cassettes remain 12-speed (no 13-speed just yet…), and the overall structure is mostly unchanged. Indeed the ratios are identical for the first 11 sprockets, with only the largest sprocket moving from 50T to 52T. Yup, that means there is now a 10T jump from the 42T to the 52T (Megarange anyone?). More on how the shifting performs in just a bit.

That’s Huge! Is It The Biggest?

Believe it or not, no it isn’t. There are a few smaller companies that produce cassettes that actually offer even more range than this new SRAM Eagle cassette. That includes the likes of e*thirteen, Leornardi Racing and SEQ-Lite. As of right now though, I believe KCNC is leading the pack with a 9-52T cassette that produces a gargantuan 578% gear range. Hooly-dooly!

What Groupsets Get The New Cassette?

But back to SRAM. For the introduction of its new 10-52T cassette option, SRAM has launched a new GX Eagle groupset, which we’ve got on test here. However, the new cassette ratio will also be available in X01 and XX1 versions to suit the mechanical and electronic variants of X01 and XX1 Eagle drivetrains. Of note is that SRAM will continue offering the existing 10-50T ratio.

…the new cassette ratio will also be available in X01 and XX1 versions to suit the mechanical and electronic variants of X01 and XX1 Eagle drivetrains

Is It Compatible With Current Eagle Drivetrains?

Yes and no. AXS wireless derailleurs are ready to go – they already feature the necessary cage architecture and pulley offset to shift up to that bigger 52T sprocket. This means if you already have an AXS drivetrain, you’ll be able to bolt the new 10-52T cassette straight on, though you might need a longer chain (and you should probably throw a new chain on with the new cassette anyway).

With mechanical X01 and XX1 however, SRAM does not recommend that existing V1 Eagle derailleurs are used with the new cassette. It sounds like it might work, but shift quality will be more laboured and less precise. As such, existing X01 & XX1 Eagle users who want the 10-52T ratio will want to consider getting their hands on the matching derailleur as well.

There’s A Nifty Setup Tool

Setting the derailleur’s B-tension is a critical step in correctly tuning a SRAM Eagle 1×12 drivetrain, and in our experience it can really make or break the overall shift quality. To help with setup, SRAM has a new plastic guide that’s designed to assist you with getting the B-tension right. Yes that makes it the third tool, but this is for sure the easiest to use yet.

You put the chain in the 2nd biggest sprocket (the 42T), fit the guide over the biggest 52T sprocket, then align the tool’s window with the pivot of the upper jockey wheel. It’s more foolproof than the current B-tension tool, and indeed it will work with all Eagle drivetrains, regardless of cassette size or derailleur type.

However, if you have a full suspension bike, you’ll still need to check this adjustment with the rider on the bike and the suspension at sag. Alternatively, you can also let the pressure out of your shock, compress it to the sag point, then run a toe-strap around the shock pivot pins to hold it at the sag point while you tune the B-tension.

New SRAM GX Eagle – Give Us The Lowdown

Along with the new 10-52T cassette, the GX Eagle groupset has been updated with a fresh ‘Lunar’ colourway that gives it a significantly higher quality look. We think it looks a lot slicker than the current GX components. There’s also a totally new rear derailleur, the option of carbon or alloy cranks, and a standard or e-MTB specific trigger shifter.

Pricing for a full 1×12 GX Eagle drivetrain starts at $959 AUD with the alloy crankset. Read on for the individual prices, confirmed weights, and specific details for each component, along with our impressions from riding this new 1×12 drivetrain.

SRAM XG-1275 GX Eagle Cassette

The big story of the new GX Eagle groupset is of course the humongo 10-52T cassette. As mentioned above, the construction remains relatively unchanged – the first 11 sprockets are all made from steel, and are pinned together with stainless steel pins along with the alloy 52T sprocket. And the cassette still mounts via the SRAM XD freehub standard – no changes there. For those wanting numbers, the ratio is: 10, 12, 14, 16, 18, 21, 24, 28, 32, 36, 42, 52.

• Confirmed weight: 453g
• RRP: $349 AUD

SRAM GX Eagle Derailleur

According to SRAM, this improves chain retention and provides more precise shifting too.

To improve shift quality, the GX Eagle mech gets updated cage architecture to help it clear the bigger 52T sprocket, while also increasing chain wrap around the cassette. According to SRAM, this improves chain retention and provides more precise shifting too. You still get the Type 3 roller bearing clutch, the X-Horizon parallelogram, along with the Cage Lock button for easier wheel removal and installation.

• Confirmed weight: 300g
• RRP: $199 AUD

SRAM GX Eagle DUB Crankset

No big changes for the alloy Eagle crankset, though it does get the snazzy Lunar finish on the arms and X-Sync 2 direct-mount chainring. Instead of being black all over, the chainring teeth are now silver on the outside face, which is simply to help them look newer for longer as they wear. There’s also a carbon crank option, which is basically a GX-branded version of the Descendent Carbon crankset. Though the carbon arms will only save you 65g for the $280 up-charge.

• Confirmed weight: 635g (175mm arms w/32T chainring, no BB)
• RRP: $269 AUD

SRAM GX Eagle Trigger Shifter

You can get this in a standard version, or a single-click version for e-MTB drivetrains.

Again, no big changes here for the GX Eagle trigger shifter. It’s still MatchMaker X compatible, and it offers the same punchy-but-smooth shift quality with its thumb-only shift paddles. You can get this in a standard version, or a single-click version for e-MTB drivetrains.

• Confirmed weight: 122g
• RRP: $79 AUD

SRAM GX Eagle Chain

No changes here with the 12-speed GX Eagle chain, which retains its solid pin construction, nickel plated outer links, smooth Flow Link inner-plates and the PowerLock connector.

• Confirmed weight: 122g
• RRP: $59 AUD

How Does It All Go?

I’ve only had half a dozen rides on our new GX Eagle test groupset, but so far everything is meshing in nicely. Setup threw no dramas my way, and I must say I quite like the improved chain gap tool for setting B-tension.

Having spent spent a tonne of time on the current GX Eagle drivetrain on numerous bikes, I’m familiar with both its performance and setup quirks. In direct comparison, the shifting on this new drivetrain is ever-so-slightly crisper, and it’s smooth too. Even back-pedalling in the big 52T sprocket, the chain stays put with no skipping to speak of. There’s still that familiar, punchy SRAM shift quality up at the paddles, but the chain engages a little quicker and with more accuracy too.

A lot of this comes down to the updated derailleur, which is more solid around the cage, making each shift faster and more precise as a result.

A lot of this comes down to the updated derailleur, which is more solid around the cage, making each shift faster and more precise as a result. Still, this is a brand new drivetrain. I’ll wait until I’ve put several hundred kilometres of riding into it with plenty of dust and mud before I make any sweeping conclusions.

As for the new gearing, it works absolutely fine. I thought that 10T jump would be a bit sluggish, but it’s not at all. The chain engages quickly – not quite Shimano Hyperglide+ quick – but it’s solid. Sure, there’s a significant change in cadence when you downshift into the 52T sprocket, but remember when we used to have 2X and 3X drivetrains? Yep, that was a far less modest change than what we have here. And ultimately the 52T works really well as that final bail-out gear for when the gradient really kicks up.

Who Needs A 10-52T Cassette?

That’s a terrific question. Personally, I’m all for low gearing – I would much rather spin my way up a climb rather than mash my knees. As such, my general preference on a trail bike is for a 30T chainring. The beauty about this bigger 10-52T cassette though is that I could upsize to a 32T chainring for more top-end speed, while retaining an almost identical granny gear.

Likewise, backcountry trail riders who favour long rides in the mountains will surely appreciate having access to a properly low gear for scaling properly big climbs – those ones that are measured in thousands of vertical metres, rather than hundreds.

Likewise, backcountry trail riders who favour long rides in the mountains will surely appreciate having access to a properly low gear for scaling properly big climbs – those ones that are measured in thousands of vertical metres, rather than hundreds.

I see the 520% range cassette as being advantageous for enduro racers, who need high gearing for sprinting on timed stages, while still having an easy gear to spin away and recover the leg muscles during transition stages. I’m not sure XC and marathon racers will see as much of a benefit, but SRAM will continue to offer 10-50T cassettes, so they’ll still have a choice there.

Flow’s Early Verdict

Adding an extra two teeth to the biggest cassette sprocket is hardly revolutionary, but the broader 520% gear range from SRAM’s new 10-52T cassette does offer greater gearing flexibility. Some riders may appreciate the new lower climbing gear, while others will use the opportunity to up their chainring size.

The GX Eagle groupset itself is a nice update on what has to be the most common 1×12 drivetrain on the market. The strengths and value-oriented approach of the previous groupset carry over, and the newly engineered rear derailleur shows promise with more crisp and accurate shifting. We’ll be putting plenty more pedal strokes onto our test groupset to see how it fares in terms of durability. We’re also keen to see how the groupset goes once it’s released into the mass market, as we suspect it’ll be spec’d on a tonne of new 2021 mountain bikes, and that’ll be the real test for SRAM.

In the meantime though, fire us through any questions you might have, and be sure to tell us your thoughts in the comments below!

Mo’ Flow Please!

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