ULTIMATE GUIDE TO SRAM MOUNTAIN BIKE DRIVETRAINS:

Since the advent of the grip shifter in the late 1980s, SRAM has been known for their innovation in mountain bike components. While their product line is in constant evolution, their commitment to performance, durability, and usability remains the same. SRAMs current crop of MTB components provides industry leading performance for all riders, with options for the race-day podium or Sunday park laps. Not only does this American-based company offer a groupset for every discipline and price point, they also maintain cross-compatibly between each, allowing riders to mix-n-match to fine tune their drivetrain to their specific needs and budget. This guide is intended to outline the differences between each groupset to help you make an informed decision on which SRAM MTB groupset is right for you.

ARTICLE SECTIONS

1X REVOLUTION  |  FEATURES & TECH  |  AXS WIRELESS DRIVETRAINS  |  XX1 EAGLE  |  X01 EAGLE  |  GX EAGLE  |  NX EAGLE  |  X01 DH & GX DH 

GLOSSARY OF FEATURES & TECH

• Eagle - the moniker given to SRAM's 1x12sp groups.
• AXS - the wireless (no cables) electronic versions of their drivetrains.
• DUB - SRAM's latest spindle size (28.99mm) and bottom brackets designed to create compatibility with all major standards of BB shells and deliver much longer bearing life.

SHIFTER

• X-Actuation - keeps your shifts consistent no matter where your at on your cassette.
• Zero Loss - a technology that eliminates free movement of your shift levers to make your shifts precise and instantaneous.
• MatchMaker X - a clamp system designed to mount your brakes, shifters, and remotes with a single clamp on each side of your handlebar. 

CASSETTE/FREEHUB

• XD Driver Body- a freehub driver standard introduced to allow 10-50t or 10-52t cassettes for a wider gear range.
• X-Dome - a process where 9 of the 10 cogs on a cassette are machined from a single block of billet steal creating a lightweight, precise, and strong cassette.
• X-Glide - increases chain retention on larger cogs and maintains quick a precise shifting throughout the cassette.
• X-Sync- specially designed tooth profiles to ensure chain engagement while allowing mud and debris to clear easily.
• Full Pin - allows SRAM to create similar cassettes to their X-Dome cassettes with a significant reduction in cost by using stamped cogs and pins.
• PowerGlide - optimised tooth profile and shift ramp design for quick and positive index shifting.

CHAIN/CHAINRING

• XD Driver Body- a freehub driver standard introduced to allow 10-50t or 10-52t cassettes for a wider gear range.
• X-Dome - a process where 9 of the 10 cogs on a cassette are machined from a single block of billet steal creating a lightweight, precise, and strong cassette.
• X-Glide - increases chain retention on larger cogs and maintains quick a precise shifting throughout the cassette.
• X-Sync - specially designed tooth profiles to ensure chain engagement while allowing mud and debris to clear easily.
• Hard Chrome - a finishing process for inner links and rollers that increases the chains resistance to wear.
• PowerLock - Quick connect links that make installing your chain easy.
• FlowLink - Ultra-smooth chain inner-plates without square edges reduces friction and wear while maintaining solid engagement.

DERAILLEUR

• Roller Bearing Clutch - eliminates derailleur bounce and chain slap without sacrificing precesion.
• X-Horizon - technology moves the derailleur along a “horizontal parallelogram” to keep the chain gap consistent between all 12 gears. This eliminates ghost shifting, leaving you with fast, smooth and precise shifts every time.
• X-Actuation - keeps your shifts consistent no matter where your at on your cassette.
• Cage Lock - holds the cage forward to make wheel removal and installation faster and simpler.

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SRAM X01 EAGLE

SRAM X01 Eagle is the best choice for the enduro rider who needs a hard-wearing drivetrain but isn’t overly concerned with weight. While it retains much of the performance of XX1 Eagle, X01 comes with some material changes to improve durability and decrease price. For example, X01 is built with a foam-core carbon crankset instead of the fully hollow XX1 crankarms. Production changes like these add up to a very minor weight penalty of around 60 grams over XX1 Eagle while maintaining all the same features and technologies including wireless electronic option. X01 Eagle is the best choices for riders seeking top-end 12-spd performance, but who are willing to sacrifice a few grams to save a few dollars.

SRAM GX EAGLE

GX gets straight to business. No claims at being the lightest weight or having fanciest features or build. Just a simple, reliable 1x12 drivetrain that provides the gear range you want at more attainable price point. Still benefitting from crisp Zero Loss shifts along the 10-50t or 10-52t cassettes, the primary difference between GX Eagle and its fancier siblings comes down to materials and machining. Without focusing on shaving grams, the machining processes are dramatically simplified, ultimately driving down costs. The most significant weight gain is found in the stamped and pinned cassette at ~450g, but this is competitive with cassettes like the Shimano XT. Also, because GX still uses the XD freehub body, you could always mix-n-match and run a higher-end cassette on your GX drivetrain to lighten the overall weight. Additionaly, SRAM did just introduce a GX-level carbon crankset that sheds some weight at a more affordable price.

DOWNHILL GROUPS - X01 DH & GX DH

X01 DH is the downhill racer’s choice. When fractions of a second count, SRAM knows you need complete confidence in your drivetrain. With feedback from World Cup pros, SRAM developed a 7-speed X01 group worthy of any podium. Downhill don’t require the same gear range as typical trail riding, which is why this option uses a 7-speed XD cassette. The X01 DH cassette has a 10-24T gear range and an integrated spoke guard to prevent the chain from bouncing into the spokes. The compact range also allows for a shorter derailleur cage, preventing the derailleur from getting snagged on obstacles.

Knowing that downhill rigs are often focused more on durability than weight savings, SRAM also offers a GX version of this DH line. Like the standard GX groupset the primary difference lies in less expensive materials and changes in machining processes. The GX DH 7-speed cassette is not XD driver-specific but mounts to a standard 8/9/10/11 speed freehub. This saves the cost of having to purchase an aftermarket XD driver for your wheels, but also reduce the gear range to 11-24t.