Adrian Marcoux

Inside the development of Eagle GX

[R]evolution was recently granted an audience with the key players at SRAM that were responsible for creating the extraordinary Eagle drivetrain.

The following conversation offers a rare insight into how the brand took their most top shelf technology to date, in Eagle XX1, and filtered it down into a price point ‘GX’ package. Eagle GX offers near identical performance but at less than half the ticket price! It was no easy feat, but with passion and commitment SRAM were able to bring Eagle GX to life. This is the story of how they pulled it off.

[R]: With the huge range and 12 sprockets to traverse, chain line is pretty extreme to say the least. Does the new GX chain, while a lower priced version of the gold Eagle XX1/XO1 version, still bring with it the intricate production process and features?

SRAM: Yes, it certainly does.  The inner and outer link geometry of the GX Eagle chain is identical to the geometry of the XX1 and X01 chains.  The difference is in the finish of the chain as well as the type of pins used.  Where XX1 and X01 Eagle chains have hollow pins, the GX Eagle chain uses solid pins.  So while the GX Eagle chain will be a bit heavier, it will provide the same shift performance and chain retention as you see with the XX1 and X01 chains.

Has the profile of the chain ring teeth needed to see any refinements since the original Eagle introduction? 

Nope.  Since the introduction of Eagle Technology systems which use our XSYNC II tooth geometry, we have not made any refinements to the tooth profiles.  With our 1×11 systems and our original XSYNC technology, we already felt we had the industry leading chain retention performance.  But after seeing that product in the market for a while, we knew we wanted to improve on the wear and noise characteristics of the ring.  So with the introduction of Eagle Technology systems we moved to XSYNC II geometry tooth profiles which greatly improved the rings in both those areas while still keeping our already best in class chain retention performance.

While the Eagle drivetrain is definitely quieter than previous 11 speed systems, does this lead to better wear/life? 

Yes, the wear and noise are actually very closely related.  The more noise you hear from a drivetrain typically means the more things are rubbing against one another and causing wear. So by improving the wear characteristics and reducing that friction, it by default starts to make the system quieter at the same time.

Moving from CNC machined chainrings to cold forged ones definitely brought the price down with minimal weight penalty, however there must be a massive increase in durability as a result? 

Not exactly.  With the specific material and heat treatment we use on our high end alloy CNC rings, we are able to actually have the same durability as our alloy cold forged rings.  The main difference between the two is certainly the price and a little bit in weight. 

Shifting focus now to the beautiful rear mech, aside from colour and material are there many differences between the top end Eagle mechs and the GX version? 

To honestly be able to hang the Eagle Technology mark onto the GX Eagle RD, we felt we had to keep all the key features and technologies from our higher end groups that make Eagle Technology perform how it does.  And so we kept the same exact layout and architecture of the RD, kept the same clutch and cage lock mechanism, and even kept the same tooth shape to the pulley wheels.  So really the difference you see between XX1/X01 and the GX Eagle RDs is mainly in the material choices, finish and manufacturing methods to assemble the product.


Crank wise, whilst not the using the exact same carbon/aluminum construction found in Eagle XX1/XO1, does the Eagle GX crankset bring with it the same kind of indestructibility of the higher end models? We hear they all sustain riding way above their intended use?

They sure do.  With all of our cranks, we tend to design and test to internal standards that would otherwise be seen and above the intended use of the product.  And we do so because we know there are folks out there that don’t necessarily fall into the intended use bucket.  And we want to make sure they have just as good of an experience on the product as everyone else.  So ya, these cranks will be just as indestructible.

Going through the specs, it would appear on the scales the only real weight gain from XO1/XX1 to Eagle GX is just in the cassette and crank? 

Those two components have by far the largest weight deltas when going from our halo level XX1/X01 Eagle systems to our GX Eagle system.  But actually every component in the system, with the exception of the shifter, gets slightly heavier as you go from XX1/X01 Eagle to GX Eagle.

"The difference you see between XX1/X01 and the GX Eagle RDs is mainly in the material choices, finish and manufacturing methods to assemble the product."

With Eagle GX now joining XX1 and XO1 Eagle groups, are the individual components in each group cross compatible? Say I bust my Eagle XO1 derailleur on a road trip, can I just bolt on an Eagle GX rear mech and keep riding without blowing my food, lift and beer budget?

Yes, Yes and more yes.  We have designed all of our Eagle Technology components to work harmoniously with each other.  We internally call it our Eagle ecosystem, where you can mix and match as your heart desires and still get the performance benefits of a full Eagle Technology group.  So if you bust your X01 Eagle RD on that road trip, you can certainly bolt on a GX Eagle RD in its place and still have money to ride up on the lift with a burrito in one hand and frosty cold beverage in the other.

Lets talk about the bottom line, aside from halving the price, there’s got to be some other additional compromises between XX1 and GX Eagle doesn’t there? 

Sure there is.  Weight is certainly a major difference.  You lose about 300g going from GX Eagle to XX1 Eagle.  So while you get almost identical performance, you do carry around some extra weight with the system when going with GX Eagle.  Ultimately it comes down to your budget.  If you have the budget and want the best of the best in every aspect including weight, then XX1 or X01 Eagle is your go to.  However, if you are looking to save some cash for your food, lift and beer budget, but not sacrifice in performance much, then GX Eagle might just be the one for you.

What about long-term durability, is there a difference in the expected lifespan of GX versus Eagle XX1?

The expected life spans will be very similar.  But with the manufacturing methods used in our XX1 and X01 Eagle components, the parts are held to a tighter tolerance which can result in the parts keeping that brand new crisp feel for a longer period of time.  That’s not to say GX Eagle isn’t durable or won’t have a long lifespan.  Just look at the long term reviews out there so far.  It’s proven to be the workhorse it was designed to be.  It’s just that XX1 and X01 are at the pricepoint they are at not only because the high level of performance, but also because of the craftsmanship that goes into them.

And finally, can you give us any hints as to if an Eagle NX ‘even more affordable again’ groupset is in the works? 

You know I can’t answer that. But what I can tell you is that SRAM is always listening to the market and doing what we can to answer the call to ensure everyone in the sport can enjoy the benefits of the technologies we bring to market.  So the more we hear the desire for SRAM Eagle technology, the better the chances are of NX Eagle happening in the future. [R]

All Photos // Adrian Marcoux