SRAM’s New XX1 Group: Details & Comments- by Guitar Ted

SRAM has been quietly working on a new, revolutionary group the past several months called “XX1”. The group will undoubtedly be seen as something of a “given”. A “one-upmanship move” on Shimano, who do not have an 11 speed off road group……yet. However; the debut of XX1 is more than another step in the sometimes frustrating proliferation of cassette cogs for mountain bikers. Let’s take a brief tour of the group, and then I will offer my comments on what I see in XX1….

SRAM XX1 Cassette, image courtesy of SRAM

11 Speeds: SRAM has stuffed 11 cassette cogs ranging from 10T to a mind bending 42T all on a new free hub body design. How did they get a 10T cassette cog on a normal free hub body, you might ask? Well, the answer is they didn’t. SRAM engineers use a hybrid free hub/driver style free hub body which has the cassette attach in a unique way as well. Of course, this means proprietary wheels for the time being, (but one would assume other companies besides the announced DT Swiss and SRAM wheels will become available eventually.) Here are some bullet points from SRAM:

“Ranging from 10- to 42-teeth, the 11-speed X-DOME™ delivers an incredibly wide gear range while maintaining even, optimized steps. The single-unit cassette combines with the XD™ driver body for a superior connection to the wheel. Available October 2012.

-11-speeds (10-12-14-16-18-21-24-28-32-36-42)
-Bearing design and ratchet mechanism steadied by XD driver body
-Creates more stable hub connection
-Gear steps optimized across entire range
-Wheels equipped for XD driver body available from SRAM and DT Swiss
-XD driver body is 6-8g lighter
-Weight: 260 grams

SRAM XX1 crankset, image courtesy of SRAM

Sans Front Derailleur: The XX1 group is designed for everything from XC racing to All Mountain riding. SRAM decided to allow its 11 speeds to cover a wider range and then to eliminate the multiple rings on the crankset. This allows for a front derailleur-less drive train, that with the available rings for the crank, can be fine tuned for whatever type of riding or fitness level the rider has. Not only that, but this is accomplished by way of a system that SRAM feels does not need a chain retention device. The teeth are taller in profile, but are also alternately thick then thin, to match the chain plate spacing as the chain passes over the chain ring. The new rear derailleur also plays a part in the system, which we’ll get to in a moment.

SRAM also has redesigned the crank, which is carbon fiber, to have its own separate aluminum spider which will fit the range of choices in rings and allows easy chain ring swaps to be accomplished. Here are SRAM’s bullet points on the new XX1 Crank:

“Developed for maximum chain control, each tooth’s thickness is precisely CNC-machined to support the chain’s inner and outer links perfectly. Six available chain rings (28-30-32-34-36-38) allow you to tune your gear range to match your terrain, wheel size and riding style. Each X-SYNC™ chain ring fits a single, universal spider—allowing you to change rings without removing the light-weight carbon crank arm. Available October 2012.

-New tooth profile alternates thickness by inner and outer links, providing maximum chain control
-Carbon arms with forged aluminum spider
-CNC-machined rings (28-30-32-34-36-38)
-New spider design allows for easier ring changes
-Wide/narrow Q factor cranks for BB30 and GXP
-Weight: 650 grams with bottom bracket (approx.)

New Derailleur Design: SRAM decided that a new type of derailleur geometry was going to work better with this system than what they had been using before. They dubbed this derailleur X-HORIZON . Instead of having the upper jockey pulley follow the cassette in two planes, (forward and horizontally), the new X-HORIZON only follows the cassette with the upper jockey wheel in a horizontal plane while keeping chain gap constant at every cassette. The lower jockey wheel actually pivots back and upwards to take up chain slack in higher gears.

SRAM follows Shimano in offering a derailleur cage arrester type technology in its ROLLER BEARING CLUTCH™, which restricts the cage movement over rough grounds and helps to keep the chain on besides making your ride quieter. Here are SRAM’s bullet points on the rear mech….

“With its “horizontal parallelogram” design and pulley offset, X-HORIZON™ keeps the chain gap constant across all 11 gears, providing fast, precise shifts. By limiting all movement to the horizontal axis, this design is faster, reduces shift force and eliminates ghost shifting. ROLLER BEARING CLUTCH™ technology reduces bounce and chain slap. CAGE LOCK™ technology makes wheel removal and installation easier than ever before. Paired with the XX1 shifter, the X-HORIZON RD forms the backbone of X-ACTUATION™ technology for unbelievably smooth shifting action. Available October 2012.

-Large upper pulley offset automatically adjusts chain gap
-Straight parallelogram design with horizontal movement reduces shift force and improves drivetrain performance
12T X-SYNC pulley wheels
-New silent pulley tooth design
-Weight: 220 grams (approx.)

SRAM XX1 trigger and Grip Shift shifters,image courtesy of SRAM

Grip Shift And A Trigger: Instead of by-passing the Grip Shift style shifter, as SRAM did when they moved to 10 speed and later introduced it, SRAM will simultaneously offer a trigger shifter in the traditional SRAM styling and a Grip Shifter. Here are SRAM’s bullet points on the shifting technology….

XX1 Trigger Shifter
SRAM 1X11 X-ACTUATION™ for precise and dependable 11-speed performance
-Multi-adjustable trigger shifter
MatchMaker X compatible
-Carbon cover and adjustable carbon pull lever
-Full Gore Ride-On cable system
-Available October 2012.

XX1 Grip Shift
SRAM 1X11 X-ACTUATION™ for precise and dependable 11-speed performance
SPEED METAL™ shift indexing
ROLLING THUNDER™ ball bearing technology
JAWS™ lock-on grip technology
-Carbon cover
-Full Gore Ride-On cable system
-Available October 2012.

SRAM’s XX1 Chain, image courtesy of SRAM.

Don’t Forget The Chain: Obviously, there is a proprietary chain for XX1. The design is said to be optimized for a drive train with no front derailleur demands, so strength and longevity are said to be improved over 10 speed. Here are SRAM’s bullet points on the new chain…

XX1 Chain
“The XX1 chain represents the latest breakthrough in a long line of precise, light-weight chains from SRAM. It’s designed to deliver the greatest strength and reliability to a drivetrain that doesn’t have to make compromises for front shifts. Available October 2012.”

-New 1X11 XX1 specific chain
-Designed for maximum strength and wear resistance
-Proprietary link finish provides improved life span
-11-speed power lock

And of course, all of this high end, cutting edge stuff comes at a price. Here is SRAM’s MSRP chart for Europe and the U.S.

USA / Europe *
XX1 Group $ 1449 € 1299
Rise 60 Wheel 26” Front Tubeless – ready Convertible Axle: $ 922 € 826
XX1 Rise 60 Wheel 26” Rear Tubeless – ready Convertible Axle: $ 1,122 € 1,005
Rise 60 Wheel 29” Front Tubeless – ready Convertible Axle: $ 957 € 857
XX1 Rise 60 Wheel 29″ Rear Tubeless – ready Convertible Axle: $ 1,157 € 1,036
X0 Hub Front Convertible Axle: $ 175 € 157
XX1 X0 Hub Rear Convertible Axle: $ 325 € 291
* Includes VAT

Comments: When I had gotten wind of SRAM’s 10-42T cassette in 11 speed, I hadn’t heard there would be no front derailleur. My thoughts were that the 42T was an outrageous choice for a double ring crank, but now that I have seen the actual group, I see how much sense this sort of an idea makes. Getting rid of front shifting, (not at all a new idea, by the way), is an admirable pursuit. Will XX1 be the realization of 1X systems for the masses? Maybe….it is a high end system, and not a lot of folks will be able to afford it at first. One might assume to think that SRAM will certainly bring this option down range at some point though.

There are a lot of new technologies here that also bear watching- the driver/free hub hybrid technology for one. Obviously this is a major departure from a long standing…..well, standard, and may limit the appeal of XX1 to a degree. The chain ring/derailleur cage technologies presented here also seem pretty forward thinking and may show the way forward to trail bikes with no chain retention devices as we know them today. Time will tell.

But beyond the extra speed, and proprietary technologies here, (which are sure to ruffle some feathers), I think the idea is a bold move. As far as 29″ers go, the range of gearing seems to be a bit short on the low end from what a triple crank matched to a 36T cassette can bring. At least with the lowest chain ring offered for XX1, which is a 28T. That said, not having the front derailleur to worry about will surely save momentum in several circumstances and may mitigate the need for the ultra-low gearing in some cases.

Stay tuned as we move forward and we will get another report up on XX1 once we have had the chance to ride it.

SRAM supplied images and information used in this post.