eagle cut 3It was a while ago now when someone leaked photos and specs regarding the next leap up in 1X MTB drivetrains from SRAM…1×12 with a whopping 50T top cog.  Wow.  I run a 50T big ring on my road bike. Called Eagle, it seemed to address one of the failings of having only one chainring, that being a lack of overall gearing range.  Most riders tended to compromise and gear down to a 30T or 28T front ring, rolling off some gear inches at the high end, a decision that works well enough on the typical trailbike.

Add one more gear and you are now able to get beyond the 42T top cog limit of the past with SRAM set ups (Shimano offers an 11-46T cassette now), so in theory you could run the same size front ring as with 1×11 and get a great bailout gear OR up the size of the chainring and get the same or slightly better low end with a higher top end gear.  Nice.  But it was all rumor and speculation.

Until now.  I am sure this has already been quipped, but “The Eagle has landed”.


eagle cut 1SRAM Eagle™ Introduction

SRAM introduced the first ever, purpose built 1x drivetrain, and is the absolute leader in 1x technology and innovation. We have manufactured, tested and ridden hundreds of thousands of SRAM 1x™ drivetrains, and have capitalized on  the lessons learned from our experience to create  all new drivetrains with Eagle™ Technology.  Eagle™ drivetrains provide unparalleled performance, enhanced toughness and durability, and the freedom of a 500 percent gear range.

In 2012, we introduced the world’s first purpose built 1x drivetrain — and it forever changed the way we ride. SRAM 1x™ changed the way we look at mountain bikes. Gone was the front derailleur, which immediately improved shifting simplicity and performance. It dropped a significant chunk of weight from the bike. It made shifting easier and consistently better for racers hitting the redline and new riders alike. It made mountain biking better for everyone. And it still does. We invented it, we build more 1x drivetrains than anyone else, and we are unrelenting in our commitment to furthering 1x technology.

Introducing SRAM Eagle™ Technology, our most advanced and highest-performing drivetrains to date. The new XX1 and X01 drivetrains, featuring Eagle™ Technology, are collections of components that have been engineered for a whole new level of ride quality and integration. These drivetrains have not only been refined, we have torn them apart, built them up, tested, tweaked, engineered and tested again. Eagle™ Technology delivers a drivetrain that is smoother, simpler, more durable and quieter than anything you’ve ever ridden. Add to that Eagle’s massive  gear range, and you have greater freedom to ride how you want, where you want. Performance, durability, simplicity, range, freedom: Introducing Eagle™, only from SRAM.

Born in the USA, engineered in Germany, made for the world. This is the newest generation of 1x technology from the people who invented it.  A drivetrain that gives you unmatched performance and a whole new level of freedom. Powerful. Tough. Decisive. Stealthy. The widest range of gears ever seen in a 1x system. Simply unstoppable. This is Eagle™. This is SRAM.


XO1 Eagle XG-1295

I will not put up all the specs and such what that by now is all over the web…go here to the SRAM Eagle page for that if you like. But I will highlight some things that stand out to me.  First of all, it did not result in a new hub driver standard, but rather fits the current XD driver.  That is good.  The 50T, while at first seeming ludicrous, actually makes sense and addresses that built in limit of having only one front ring.  From what I have read, it seems to shift very well.  If it were I, I would run the same size front ring I have now, say a 30T, and just keep the 50T big cog in my back pocket for moments that really called for it.  That would be to my advantage as the 50T is aluminum, not steel, and will likely wear out faster than the rest of the cassette (although the larger diameter will help in that regard).

SM_PC1290_Chain_Gold_Front_MHIt is a sharper chainline now, at least by a bit, so the new chain design better be a flexy beast.  It is supposed to be quieter than the 11spd chains we have now, and is supposed to last longer too.  In any case, two bikes I have around me now, both Plus versions, will walk the chain off the top cog if you back pedal a full revolution.  I don’t see spacing over to another cog helping that any, so will will have to see how this works out long term…wear and noise, etc.

The X-SYNC™ 2 chainrings have a dramatically different tooth profile.  They look pre-worn out, but SRAM says they will last much longer than the current 1×11 rings they offer.  If so, that is good as that single, smallish chainring takes a real beating and does not last all that long in it’s current form.


The rear der is a complete re-design to work with the new range, but still has the clutch tech in it as before, now said to be smoother operating as well in the “Type-3 ROLLER BEARING CLUTCH™” version.  Note the bigger bottom pulley. And, you can get Gripshift, if you like.

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There are two levels as of now…XX and XO.  The cranks differ and XX has more carbon bits here and there, shaving grams.  The gold lame’ treatment is kind of blingly, but it befits the cost of the new XX1 Eagle.  For instance, the cassette: An XG-1299 cassette is $420.00 US.  Oh. Wow.  But XX in any form has always been costly and the Powerdome tech in the cassettes comes at a big price, although they are darn near lighter than air.  XO1 Eagle gets better, but you still are paying a lot for a consumable item like a cassette.  The XO1 Eagle XG-1295 version is $360.00.  If you needed to replace the chain at $60.00 and the ring at $90.00, then that is $510.00…never mind what XX1 Eagle would be.  Oh man….


Yes, this will trickle down to a X1 Eagle in time, or one would think so.  But it sure makes a 2X set-up look like a bargain if gearing range is important to you.  The front der may be dead, but at what cost?

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