Among the bikes we've gathered for our upcoming Enduro Compare-O shootout we've noticed a trend--a majority of these test bikes are arriving with 1x11 drivetrains. Companies want to put their best foot forward in this comparison and it looks like they want their bikes tested with the new SRAM X01 or XX1 drivetrains. Most of them have Shimano brakes mated with the SRAM shifters. This is not the easiest combination with lever and trigger real estate but it seems pretty well sorted this year. The combination of SRAM drivetrain and Shimano brakes seems to be popular these days.

And another observation, there seems to be a lot of Pike forks on these bikes these days. Most of these bikes still have Fox rear shocks as companies seem to mix and match to create the best combination possible to showcase their bikes.

Niner WFO9 with SRAM X01

We think the revolution has started. Read on and find out why 1x11 is taking on the world.

What is it?

The X01 is SRAM's less expensive follow-up to the wildly successful XX1 drivetrain which features 1x11 drivetrain and no front derailleur and 11 speeds in the rear.

X01 Derailleur - X-Horizon zero slant design, Type 2 clutch technology
Weight: 220 grams, $269 MSRP

X01 Crankset - Carbon arms with forged aluminum spider, 170 and 175mm lengths ,94 BCD, Bash guard option, 30, 32, 34, 36 or 38-tooth
Weight: 645 grams (5 grams heavier than XX1), $279 (GXP) and $319 (BB30) MSRP

XG-1195 Cassette - 11 speeds (10-12-14-16-18-21-24-28-32-36-42 teeth) , Hard plated with black surface treatment
Weight: 275 grams (15 grams heavier than XX1), $399 MSRP

X01 Trigger Shifter
91 grams, $139 MSRP

X01 Grip Shift - Rolling Thunder ball bearings, Lock-on grips included
143 grams, $129 MSRP

PC-XX1 Chain - 1x11 specific, Hard Chrome technology
$63 MSRP

Why you want it

You want it because it is truly a revolutionary drivetrain for mountain biking. Just as drivetrains improved when they went from 3x10 to 2x10 a few years ago, this new 1x11 is an even more dramatic improvement. It not only works well, it is changing the face of drivetrains and even mountain bike design.

Front derailleurs never really worked well as the system was designed around a metal plate derailing a chain by pushing it from one side or the other. That meant that the chain had to be easy to derail with shorter teeth on the chainrings and the plates had to be placed close to each other to derail the chain from either side. This resulted in a chain that would fall all the time and a derailleur that would rub the chain often. Various systems were devised like chain guides, direct mounts and even electronic trim devices that would prevent rubbing automatically. All were an effort to fix a design that is inherently bad for mountain biking. Couple that with the fact that the system could not really shift between gears under full power loads.

So the elimination of the front derailleur in the SRAM X0 1x11 system has many benefits. But perhaps the biggest benefit of the SRAM X0 system is that the chain does not fall anymore. Since derailing the chain is no longer a requirement, SRAM devised an alternating narrow/wide chainring design that syncs up with the narrow/wide spacing of a chain. The result is a chain and chainring that mesh with each other. The chain does not lift from the chain and it thus stays in place even on the rockiest descents.

What are the downsides?

Cost is high as it only goes down to X0 level.

Gearing is not as low as 2x10. The lowest gear is 30 front, 42 rear and this can be a concern for heavier riders, high mountains or 29ers or heavier bikes. The XX1 has a smaller BCD (bolt pattern) and can take a 28-tooth front ring. The X01's smallest allowed ring is 30 teeth. Use this Bike Gear Calculator to check how 1x11 gearing range compares to your current setup.

You need a new hub body called an 'XD Driver Body'. Most newer hubs are compatible with this and the new body will accommodate the small 10-tooth ring. If your current wheel does not accept an XD Driver Body conversion, you will need a new wheel.

Is it a Revolution?

The transition to 2x10 was an evolution. But we think the arrival of 1x11 is a revolution and here's why:
  • Less chainslap and almost no dropped chains with no chain guide
  • More useable gear range in the back means shifting is more seamless
  • No gear duplication
  • No chainsuck
  • Noticeably lighter with less parts
  • No front derailleur which is hard to adjust and doesn't work that well
  • More room on the bars, makes room under the bar for the dropper post
  • Rider is always on the correct chainring in the front when on rolling terrain with steep walls
  • On full suspension bikes, the front chainring can always be the right one for the suspension design as most suspensions are usually optimized for just one of the chainrings where they remain neutral under load
  • It allows frame designers to shorten the chainstays when eliminating the front derailleur. This is key for 29er FS.

1x11 Poll Results

In a recent poll by Mtbr here, it's obvious that experience so far with SRAM 1x11 drivetrains is very positive. 20% of respondents have tried it and think it's the best drivetrain they've ever used. Another 52% have not tried it but are interested.


The X01 is every bit as good as the XX1 in terms of feel and functionality. It's about 10% cheaper and a few grams heavier. But in a blind test, we would not be able to tell the two apart. So just like the XX1, we give the X01 our highest recommendation.

More info is available here: Complete Specs and Info on SRAM X0 1x11.

Product Introduction by: Brian Mullin

Video: SRAM X01 All for One

The XX1 group brought 1x11 gearing technology to the masses last year, and it has proven itself for both racers and consumers. It offers snappy quick shifting, simplicity, lighter weight and good chain retention capabilities. The not very secret SRAM X01 group has been officially announced to the world, and the new brethren of the XX1 are cheaper and has the same basic technologies and designs, with some subtle changes and alterations for cost savings. While not exactly inexpensive, it does decrease the cost for entry to the SRAM 1x11 drivetrain system, with only a small weight penalty.

In a nutshell, in direct comparison to XX1, the crankset uses a different BCD, a less sculptured rear derailleur and chain, shifters with aluminum cable covers, and a cassette with a new durable coating.

The crankset uses carbon fiber crank arms and an aluminum spider, but forgoes the more expensive to produce XX1's 76mm BCD (bolt circle diameter), and goes with a 94mm BCD. Unfortunately, this conversion means there's no room for a 28-tooth chainring, so they'll only be available in 30, 32, 34, 36 and 38 sizes, but it does mean they'll now offer an optional chainring guard option. The CNC machined aluminum chainrings use the X-SYNC tooth profile for better chain control and retention. The cranks will come in red and black, 170 and 175mm arm lengths, BB30 and GXP bottom bracket options, wide and narrow Q-factor, weigh around 655 grams and retail for $279 (no chainring or BB). The chainrings will retail from $98 to $127, depending on sizing.

For 29er riders and those that like low granny gear ratios, the loss of the 28-tooth chainring is a big deal, so you might see many people using the XX1 crankset with the rest of the X01 system.
  • New patented X-SYNC™ tooth profile provides maximum chain control
  • Carbon arms with forged aluminum spider
  • Chainring guard option
  • New spider design allows for easier ring changes
  • CNC- X-SYNC™ machined rings (30-32-34-36-38)
  • Colors: Red and Black
  • Weight: 655g (with BB)

The X01 gets all the XX1 technology, including the X-HORIZON horizontal parallelogram design, the 12-tooth X-SYNC pulley wheels, carbon-fiber cage and TYPE 2 rolling bearing clutch. The only difference I can tell between the X01 and XX1, is some more sculpturing of the derailleur body. The X01 rear derailleur comes in red and black, weigh 252 grams and retails for $269.
  • Large upper pulley offset automatically adjusts chain gap
  • X-HORIZON™ design reduces shift force and ghost shifting
  • 12-tooth X-SYNC™ pulley wheels
  • Carbon or aluminum cage
  • Sealed cartridge bearings
  • Colors: Red and Black
  • Weight: 252g

The X01 shifters gets an aluminum top cover instead of the XX1's carbon fiber, but they still use the X-ACTUATION shifting and Zero Loss Travel design. The X01 trigger shifters comes in red and black, weigh 91 grams and retail for $139.
  • SRAM 1X™ X-ACTUATION™ for precise and dependable 11-speed performance
  • Zero Loss Engagement for fastest shifting
  • Multi-adjustable trigger shifter
  • MatchMaker X compatible
  • Aluminum cover and adjustable forged aluminum pull lever
  • Includes discrete clamp
  • Colors: Red and Black
  • Weight: 91g

The X01 Grip Shift gets an aluminum cable cover instead of the XX1's carbon fiber, but they still use the X-ACTUATION shifting, SPEED METAL shift indexing and ROLLING THUNDER ball bearing technology. The X01 Grip Shift comes in red and black, weigh 143 grams and retail for $139 with the JAWS lock-on grips.
  • SRAM 1X™ X-ACTUATION™ for precise and dependable 11-speed performance
  • SPEED METAL™ shift indexing
  • ROLLING THUNDER™ ball bearing technology
  • JAWS™ lock-on grip technology
  • Aluminum cover
  • Includes lock-on grips
  • Colors: Red and Black
  • Weight: 143g (clamps, cable and JAWS™ lock-on grip)

The X01 cassette uses a new dark finish, which is supposed to be more durable and long lasting. They use the same XX1 manufacturing technique to create the cassette; they CNC a solid block of 4130 chromoly steel into a 10-speed system, and then pin on a 42-tooth cog. The X01 X-DOME cassette has the same 10-12-14-16-18-21-24-28-32-36-42 gear ratio as the XX1, attaches to the XD driver body, weighs 275 grams and retails for a whopping $399.
  • Unique finish for high durability
  • 11-speeds (10-12-14-16-18-21-24-28-32-36-42)
  • XD™ Driver Body creates more stable hub connection
  • Optimized Gear steps across entire range
  • Weight: 275g

The X01 chain uses the same HARD CHROME plating and hollow pins as the XX1, but doesn't have the XX1 weigh saving cutouts between the pins. The chain retails for $63.
  • New 1X™ specific chain
  • HARD CHROME™ technology for maximum strength and wear resistance
  • Proprietary link finish provides improved life span
  • 11-speed power lock