What was Specialized trying to achieve with the redesign of the Enduro?
Make an even faster Enduro or, more precisely, an Enduro that would be faster in every situation. There’s a lot to unpack there, so
here are the highpoints. We wanted to improve the following: initial stroke (small-bump) sensitivity; bottom-out resistance (big-hit
performance); pedaling efficiency; ride characteristics under braking; chassis stiffness traits; and its ability to maintain momentum
over truly technical terrain.
How many models are there now?
We’re offering four new Enduro 29 models, as well as a standalone S-Works frame option.
You say that improving momentum carry was key to this bike—that it’s all about making the bike faster on rough descents.
How’d you achieve that?
This was a major goal for us. We wanted to reduce rear wheel hang up on square-edged hits and that meant significantly changing the
axle path—making it more rearward in the first third of the stroke.
Why isn’t the axle path “more rearward” throughout the rear shock’s compression stroke?
Your rear wheel moves up and over big rocks and roots more easily with a more rearward axle path. Consequently, we can improve
momentum carry by tweaking the rear wheel’s axle path. But when you say “more rearward” a lot of people envision the rear-axle
shooting backwards in space indefinitely whenever you hit something really chunky. That’s not the case for any bike.
In reality, all rear-axle paths scribe an arc in space as the rear suspension compresses. The axle path initially goes rearward, but
eventually arcs forward. So, really, what we’re trying to do is have an axle path that scribes an arc that is more rearward—or less-
forward arcing, really—as the rear suspension compresses.
Too convoluted? Just look at the graph below, because it shows less nouns and more actual axle paths. Red is the new Enduro 29.
Blue is the Enduro you’ve been riding the past few years. The new axle path defined by the red line is, in fact, more rearward during
key segments of the rear travel. This axle path thing only matters because it reduces rear wheel hang-up and helps the new Enduro
maintain momentum and haul ass through really rocky terrain.
How exactly did you achieve that improved axle path?
It required a wholesale change to the Enduro’s kinematics. The new main pivot placement was a primary contributor to getting that
more rearward axle path.
If a “more rearward/less forward” axle path is better at allowing the rear wheel to move away from and then over big,
square-edged hits, then why didn’t you go even more rearward?
There’s no point in chasing one ride characteristic at the expense of other important ride traits. The goal is to achieve the right mix of ride traits. For example, if you go too far rearward with the rear-axle path, you start getting excessive amounts of chain growth and that, in turn, can give you excessive amounts of pedal kickback. This affects your pedaling performance. If the rear-axle is traveling too far rearward on big hits, you also wind up with your geo (wheelbase in particular) changing distractingly in really technical sections of a descent. In other words, you can overdo the whole rearward axle path thing. We wanted the Enduro to be faster across the widest range of conditions possible, and this means achieving the right balance of suspension characteristics.
This new Enduro looks more complicated than its predecessor. Why so many links?
The new suspension layout, which debuted on the Demo, allows us to achieve several key objectives. For starters, the two extra bars
give us more flexibility in tuning the leverage curve. Making the bike both more supple and improving bottom-out resistance were key
for the redesign, and the extra tuning options afforded by the design helped in achieving that.
Could we have reached that same suspension feel with the previous design? Yes, we could. The stand-over height, however, would have
been higher, as would the bike’s center of gravity. So, to parse this answer down, the new design gives us more flexibility in tuning the suspension feel and helps us place the weight lower on the chassis while keeping standover height lower. And all of this adds up to more maneuverability and control on the trail.
Why no 27.5 Enduro?
The new Enduro is all about speed. Reaching it quickly, not hanging up in the chunder and, consequently, maintaining momentum like a champ. 29-inch wheels excel here. This doesn’t mean that we’re in a blood feud with smaller wheel sizes. There’s definitely a place for 27.5 in our mountain line, but for this iteration of the Enduro, 29-inch wheels are the perfect match.
How did the geometry change between the new Enduro and the previous version?
Here’s where we type “longer, slacker, and lower” and you try not to roll your eyes, and then we try not to feel like we’re just repeating the same old mantra over and over again. So, go ahead and check-out the geo chart comparison below; there are plenty of numbers there that illustrate the head angle slackening, reach growing, and the seat tube getting steeper (among other things).
Another, more subtle (but important) point is that we now offer the Enduro in our Style-Specific Sizing—so you’re looking at, say, an S3 or S4 or S5 instead of a Medium or Large. The point of Style-Specific Sizing is to highlight that, now, almost any single rider can choose between a couple of different frame sizes.
Very low standover heights and very long dropper posts allow riders to really choose their frame size based on how they want the bike to handle. Your desired reach and wheelbase, for example, now become the measuring stick by which you choose. Pick your bike based on your riding style instead of simply relying on the measurement between your crotch and the ground.
The Enduro is a carbon-only affair. Why isn’t there an aluminum Enduro 29?
We wanted to create the lightest, most bad-assed bike in this genre. Carbon was the ideal frame material for making that happen. And while there are no aluminum models in the new Enduro line at this point, there are still places in our larger bike lineup where alloy makes sense and will see continued usage.
What sets the S-Works Enduro frame apart from the other carbon Enduro frame?
In a word, weight. Ride feel (chassis stiffness) is the same between all of the carbon Enduro 29 frames, but the S-Works frame sports all-carbon top, middle and lower links, which shave an average of 250 grams (.55 pounds) from the overall frame weight.
Your release says you were looking to create a frame that had the right balance of stiffness. What’s that actually mean?
Did the Enduro get stiffer in the front? Stiffer in the rear? Less stiff?
On average, the rear-end on the new Enduro 29 is 12% stiffer than that of the previous bike (comparing 29er Enduro to 29er Enduro). The front-end stiffness remains the same.
You say you built more anti-squat into the new Enduro. How much more anti-squat did you add?
It’s impossible to give a single anti-squat value since anti-squat is a force that results from multiple factors that can change: the bike’s instant center location, chain force vector, and center of gravity. Accordingly, your height, the size of the chainring you’re pedaling, and the cog you’re using at any given moment can impact anti-squat value. Same holds true for your instant center, which (on anything other than a single-pivot bike) is constantly in flux as the rear wheel moves through its travel.
So, rather than cherry-picking a single, meaningless anti-squat value, we’ll put it this way: Holding gear combination, wheelsize, and rider weight constant, we’ve increased the Enduro’s anti-squat value by 40%. There’s a significant increase in pedaling efficiency. Shifting the Enduro’s instant center (by changing the linkage and its orientation) had a big impact here.
What about the leverage curve on the new Enduro? How has it changed?
In a nutshell, it’s more progressive. We’ll dispense with the words and go straight to the leverage rate curve