Evolution is not what you’d call “snappy”. About 5.8 million years ago our ancestral line split off from that of the great apes. While there was much hooting, lurching about on hind legs and awkward high-fiving at the time, things quickly stalled out. For three million years. It took three thousand friggin' millennia for Homo Habilis to stumble upon a rock and think, “Hell, I bet I could use this thing to smack my neighbor and steal his pile of ants.”
Three million years to invent the handle-less hammer. So, yeah, evolution—it’s not so quick on the gas. The exception to this rule? The modern mountain bike.
Mountain bikes evolve at a dizzying rate. Consider the Specialized Enduro. In 1999, the Enduro debuted as a pudgy trail bike with an odd name. Seventeen years later, the Enduro has metamorphosed no fewer than eight times. The result? A super bike that weighs less and climbs better than its progenitor, yet offers the kind of descending performance that was once the sole purview of downhill bikes.
Over the years, the Enduro has often defined its niche—the lightweight, long-travel ripper. That isn’t to say, however, that every Enduro has been flawless. There have been glorious advances and ugly stretches alike. Evolution is a messy affair. Here’s how it unfolded for the Enduro.
This probably wasn’t what you were expecting. The first Enduro was really just a riff on Specialized's existing Ground Control FSR models - a component-spec option rather than an entirely new line of bikes. Few people realize the Enduro was born here in 1999, but if you look closely, you can glimpse the future.
1999 FSR "Enduro" Pro
• Lifespan: One year
• Designed by: Mark Dinucci
• Design intent: "Everything...this was before full suspension became so segmented."
• Frame material: Specialized M.A.X. Aluminum
• Fork travel: 80 millimeters (3.15 inches)
• Rear wheel travel: 109 millimeters (4.3 inches)
• Geek facts: Front triangle made in Portland, Oregon
Specialized began making its popular Ground Control FSR bikes back in 1997. At the time, they were considered long-travel bikes. While they may not seem like gravity sleds by today’s standards, the Ground Controls were rugged and capable for their time. The bikes were configured around Horst Leitner's patented, four-bar, rear-suspension system and featured a burly, extruded-aluminum “MAX Backbone” front triangle, which was crafted for Specialized by Anodizing Inc., in Portland, Oregon.
The Ground Control FSR models--the Elites, Pros and Extremes (yes, there really was an “Extreme” model) were the mini-DH bikes of their day. Which is another way of saying they weren’t exceptionally light. Coil-sprung shocks and dual-crown forks added mass and limited their appeal. Enter this Enduro Pro model, which boasted the same 4.3 inches of rear-suspension travel, but opted for a lighter build kit.
Up front, the bike was spearheaded by a....RockShox SID XC? Yep. By today's standards, the three-inch travel SID boasted all the rigidity of overcooked fettucine, but the fork was, again, a nod to lightweight performance. This was 1999—everyone in the States seemed to be weighing their chain lube and trimming their handlebars—the SID was the fork of the moment, which probably explains why the first Enduro also wore a SID shock. As for stoppers, disc brakes were still a rarity at the time, so V-brakes got the deed done. Kinda. Sorta.
The first Enduro was a solid bike for its era. "It was technically very advanced," recalls Specialized's senior design engineer, Jason Chamberlain. "The mainframe was a triple-cavity extrusion that was then machined and bent. That was a pretty tricky engineering feat."
But groundbreaking? No, you couldn't toss that adjective at what was a slightly hopped-up version of their existing Ground Control model. In fact, if you were the betting sort, you probably wouldn't have wagered much on the proposition that the Enduro would even stick around for long. The hot bike in Specialized's 1999 line, after all, was the Stumpjumper FSR XC - a featherweight, short-travel bike. You kind of have to squint at the 1999 Enduro to get a sense of where it was going. But it was going places. Fast.
Starting From Scratch
Now, this is the bike that most people think of as the first Enduro. Though the 2000 Enduro was, essentially, a burlier, longer-travel version of Specialized’s lightweight FSR XC model, it also had an identity of its own, thanks to the disc brakes, much more capable suspension and, yes, those mud flaps.
• Lifespan: Two years
• Designed by: Mike Ducharme and Robert Egger
• Design intent: "Long travel version of our XC bike."
• Frame material: Aluminum
• Fork travel:100 millimeters (4 inches)
• Rear wheel travel: 97 to 117 millimeters (3.8 to 4.6 inches)
• Geek facts: Adjustable geometry and rear suspension travel
Looking at this bike you can see where Specialized is heading: Less flex, less weight, more squish and a nod to climbing performance. Today those seem like obvious goals for just about any bike, but in 2000 there was a yawning gulf between cross-country dualies (such as the Santa Cruz Superlight and Specialized FSR XC) and the more gravity-oriented rigs. Relatively few bikes surfed the divide. This Enduro, however, plunged right into the gap. You could tweak the suspension and frame geometry via a four-position shock link and even though it only boasted 40 millimeters (1.6 inches) more rear travel than the company’s featherweight cross-country racer, the suspension was world’s more capable.
The first Enduro frame design was basically a burlier, squishier version of this bike - Specialized's featherweight FSR XC.
There were a few important details in the first Enduro frame that often go overlooked. Bearings top the list. “This was possibly our first bike with bearings at the pivots (instead of IGUS bushings),” says Specialized’s Chamberlain. “I distinctly remember Mike Ducharme and Shawn Palmer yelling back and forth about bushings and bearings. Palmer insisted he had to have ball bearings like his Intense. Ducharme insisted bushings were good enough. I think this was the turning point for the industry where everything that followed had to have cartridge ball bearings.”
The components also set the Enduro apart from most of its competition. The bike was built to get rowdy, or at least rowdier. Disc brakes were also just beginning to gain traction as an original equipment item and there was only one brand that made solid, powerful and reliable brakes in 2000—Hayes. The Enduro rocked a set, thanks to a novel, if-sorta-wonky rear disc brake adaptor. The bike also sported riser bars, beefy frame gussets and fenders front and rear. Why did a longer-travel bike suddenly need mud fenders? It didn’t, but it sent a message: The Enduro was not like other bikes.
The Big Leap Forward
This, as the kids are fond of saying, is where shit gets real. In 2002 the Enduro made a massive leap forward with its semi-monocoque front triangle and a shock from the future that instantly bumped up suspension travel at the flick of a switch.
• Lifespan: Three years
• Designed by: Jason Chamberlain and Robert Egger
• Design intent: "To be the Swiss Army knife of bikes."
• Frame material: Aluminum
• Fork travel: 80-130 millimeters (3 to 5.1 inches)
• Rear wheel travel: 100-132 millimeters (4 to 5.2 inches)
• Geek facts: On-the-fly adjustable suspension--front and rear.
Up until 2002, the Enduro was derivative—a spin off of already-popular Specialized models. This time around, the Enduro was a beast of its own making. The "TransForm" frame looked like a science-fiction movie prop and it was backed up by a proprietary Specialized-designed-and-Fox-built shock. Simply flick the “Itch Switch" and the bike went from four to five inches of travel. Up front, you could do the same with the Fox TALAS fork. While the previous version of the Enduro featured adjustable travel and geometry, it required pulling out the hex wrenches to make the swap. Now, all you had to do was flex an index finger. Brilliant.
If all that sounds like just so much gimmickry and cleverly-trademarked names (the latter of which is, admittedly, a Specialized specialty), there’s also this: The 2002-2004 Enduro was one of the most competent bikes of its time. Which bike is “the best” at any given time is always a matter of debate, but it’s hard to argue with this point: The Enduro defined its niche during this period. Lightweight, crazy-versatile and sexy as all hell.
"We wanted it to be the longest-travel trail bike going--yet as light as most XC bikes," recalls Chamberlain, who cut his teeth working on this model. "We never really had another bike on our radar. We usually never do. We just build what we personally want to ride ourselves. Back then, a lot of trail riders liked to stop and session stuff on the side of the trail, so we designed this to handle big stuff (big for the day) while being light enough to get anywhere you wanted to go. It was like the Swiss Army Knife of bikes – adjustable to do it all."
In its final year of production, this iteration of the Enduro were equipped with Brain remote shocks. It was a very XC touch, though the Enduro would soon move in the other direction.
What could have been improved? “It wasn’t possible to vary the wall thickness with monocoque technology at the time,” says Chamberlain, “so it wasn’t as light as it could be, but the Enduro was still one of the lightest bikes of its type at the time.”
Enduro Goes Aggro
If the 2002-2004 Enduro was the all-purpose, people-pleaser bike, the 2005 and 2006 editions marked the Enduro’s angry adolescent phase.
You want a bike that locks out and climbs like an XC bike? Screw you, buddy. This Enduro lived to descend. Simple as that. The 2005 and 2006 Enduros were fierce (and polarizing) bikes.
• Lifespan: Two years (later rebadged as "SX Trail")
• Designed by: Jason Chamberlain and Robert Egger
• Design intent: "Long travel, plush and burly."
• Frame material: Aluminum
• Fork travel: 150 millimeters (6 inches)
• Rear wheel travel: 152 millimeters (6 inches)
• Geek facts: One of the first bikes equipped with a long-stroke, large-volume, air-sprung shock.
Burly. There’s no mistaking this Enduro’s intentions. The bike is one big orgy of forged frame components, a low-slung cockpit and suspension components aimed squarely at descending. If you want to climb big peaks all day, you were knocking on the wrong door. Amazingly, the new aluminum frame didn’t gain weight—it tipped the scales at 6.9 pounds, but there was no shortening the bike’s six inches of rear suspension or “locking-out” of either the fork or shock.
The Enduro was equipped with the new Fox 36—the longest-travel, single-crown fork of the day, as well as an extra-long stroke, large- volume air shock. In an effort to maximize the smooth, the new Enduro eliminated DU bushings in the shock, replacing them with outboard ball bearings, which lasted much longer and provided a more supple feel.
The bike was a ripper. In 2006, the Enduro line diverged with a new SX Trail model getting a rowdier build kit and a bump in travel, from 150 to 168 millimeters. With its low center of gravity, slack angles and deep suspension, the Enduro was a go-to model for the descending set. Which also means that it didn’t appeal to as broad an audience as earlier Enduros.
“Riders continued to progress and develop increasingly aggro expectations of their trail bike, so we went big” says Chamberlain. “Journalists, connoisseurs and shop guys loved it. And internally this Enduro was the personal bike of choice for most of the product development team. Sales were good, but it was probably ahead of its time—too much bike for most people. A lot of people still wanted XC bikes that locked out.”<
The Black Sheep
The 2007 Enduro was a head turner and a departure. Specialized boldly ditched the basic swing-link shock layout in favor a rocker link. Moreover, this Enduro was equipped with forks and shocks designed by Specialized. The bike had big potential…and a few big problems.
2007-2009 Enduro SL
• Lifespan: Three years
• Designed by: Jan Talavasek, Jason Chamberlain and Robert Egger
• Design intent: "A lighter weight, XC version of the Enduro"
• Frame material: Carbon/aluminum and all-aluminum models
• Fork travel: 150 millimeters (6 inches)
• Rear wheel travel: 150 millimeters (6 inches)
• Geek facts: Carbon Enduro debuts. Specialized-branded suspension, dual-crown forks.
While the 2005-2006 era Enduro was much loved by downhillers, it was more bike than many riders wanted. This new version aimed to correct that. In fact, it aimed to do a lot of things. Lightweight and efficiency were, again, at the top of the priority list, but how Specialized achieved it was radical.
The frame was an entirely new, swoopy-tubed affair. For the first time, there were both carbon-fiber (front triangle) and aluminum Enduro models. Frame weight dropped significantly. The carbon edition tipped the scales at a feather 5.5 pounds with its shock. The complete pro model weighed less than 28 pounds. Those figures are still impressive today.
For 2007, Specialized went all in on “Total System Integration”. By designing more than just the frame, Specialized intended to make a bike that worked better as a unit. The bike would now wear Specialized forks, shocks and wheels. The company rehired Mike McAndrews to head up a new suspension unit. McAndrews had previously led R&D at RockShox, launched Fox’s fork line and designed some of the key suspension components at Paul Turner’s Maverick brand.
The initial results were impressive. Consider the FutureShock E150, a 4.5-pound, 150-millimeter (six-inch) travel, dual-crown fork with 35-millimeter stanchions and a massive 25-millimeter through axle. If those stats don’t get your geek blood boiling, I question whether your heart is even beating. Or, maybe, you just know how this chapter of the story ends. Badly.
Specialized's first carbon Enduro had a frame weight of less than 5.5 pounds. Complete bikes weighed less than 28 pounds-and that was with the dual-crown fork. Damn. Reliability issues, however, plagued both the shock and fork.
Both the radical fork and the Specialized “AFR” shocks were prone to failing. The bike developed a reputation as a brilliant idea that didn’t pan out. When it comes to manufacturing reliable suspension, the execution is just as critical as the design itself.
“I think we underestimated the complexity in manufacturing shocks and forks,” says Chamberlain. “It was a collaboration with a young factory (at the time) and I think both parties struggled with the volume and time challenges.”
What did Specialized learn from this version of the Enduro?
“Riders preferred brand name suspension and they didn’t like proprietary parts (stem and 25mm hub). We also learned,” continues Chamberlain, “that lightweight is always a driver and that carbon was a suitable material for aggressive, heavy-duty trail bikes.”
A Return to Form
The 2010-2012 Enduro ushered in a new era. Gone was the rocker-link design of the previous model. The new bike was, in many ways, a more efficient, featherweight version of the company's 2009 SX Trail model.
The all-new “X-Wing” front triangle debuted on this Enduro and it would prove (after the Horst Link, itself) one of the most resilient design features to ever grace the Enduro line. This new bike was stiffer, lighter, more capable and more reliable than the model that preceded it.
• Lifespan: Three years
• Designed by: Jan Talavasek and Ian Hamilton
• Design intent: "Even longer travel. Even lighter."
• Frame material: Both Carbon/aluminum and all-aluminum models
• Fork travel: 160 millimeters (6.3 inches)
• Rear wheel travel: 160 millimeters (6.3 inches)
• Geek facts: 20 percent boost in frame stiffness. Shock extension allowed for full-length seat post to co-exist with swing-link design.
By the time 2010 rolled around, Specialized found itself in a new position—they needed to catch up. There were plenty of great bikes out there that were only too happy to eat the Enduro’s all-mountain lunch, including the Santa Cruz Nomad and Trek Remedy. Specialized responded with this—a sleeker, svelter version of their 2009 SX Trail. The SX Trail was a downhill assassin, which gives you a sense of where this new Enduro was going. Specialized improved upon the SX Trail’s pedaling efficiency, lopped off plenty of weight and were back in the game.
2010's Enduro, with its "X-Wing" frame borrowed heavily from the company's lightweight freeride SX Trail, and proved a return to form.
The company hadn’t entirely given up on proprietary suspension bits. The high-end carbon versions were equipped with a carbon-crowned, 160-millimeter travel Specialized E160TA fork that weighed a mere 4 pounds and featured adjustable travel.
This fork required a proprietary headset lower assembly, though the company had clearly learned from the previous Enduro—they sold an aftermarket bearing kit that let you also run non-Specialized forks. That bearing kit came in handy since the Specialized fork still wasn’t as reliable as most of the competition.
At the rear of the bike, Specialized wisely opted for a Fox shock. The shock, however, was a proprietary affair which mated to a shock extension. Again, this was a feature that debuted the prior year on the SX Trail.
"The 'shock extension' is an idea that I had because I was tired of designing seat tubes around shocks, and decided to start designing shocks around seat tubes," says Chamberlain. "Riders still wanted to slam their saddles and we just couldn’t eke out any more seatpost travel with the shock in the way. A 'rocker' design was really the only other option, but too many competitors owned that look. We wanted to get back to a unique 'Specialized' look." The design also left more room for a water bottle mount in the main triangle
Though Specialized owns five patents surrounding the shock extension concept, they clearly haven't fought to keep it out of other companies' hands - it's a feature that's popped up on plenty of competitors' bikes since then.
The All 'Rounder
At first glance, it doesn’t look like the Enduro changed much in 2013 (same X-Wing design, same geometry). The tweaks are subtle on paper, but profound on the trail.
This version handily dropped its predecessor on the climbs, lost a bit of weight and gained stiffness. Moreover, the Enduro managed to maintain its nimble go kart handling while weathering the wheelsize storm that blew through the bike industry during these years. Hello, 29er and 27.5 Enduro.
• Lifespan: Four years
• Designed by: Jason Chamberlain and Dennis Wrobleski
• Design intent: "More travel and lighter--again. And in every wheelsize."
• Frame material: Both Carbon/aluminum and aluminum models
• Fork travel: 160 millimeters (6.3 inches)
• Rear wheel travel: 165 millimeters (6.5 inches) for 26 and 27.5. 155 millimeters (6.1 inches) for 29er
• Geek facts: Eventually available with 26, 29 and 27.5-wheels.
All-mountain bikes are the most demanding models to design. People want their burly six-inch travel bike to climb like a goat and descend like a DH bikes. That’s a lot to ask for. It’s also why this niche generally turns out the most innovative models—people demand it. No surprise, then, Specialized tweaked the 2013 Enduro’s kinematics and shock tune to improve the bike’s pedaling efficiency, they bumped up rear-suspension travel a smidge (five millimeters) and trimmed about a quarter pound from the carbon frame and boosted stiffness with the adoption of a 142x12 rear through axle. The changes sound small, but they were immediately noticeable the moment you began pedaling.
Those changes might have been enough, but they paled in comparison to the next tweak to the formula: 29-inch wheels. Let’s be clear, no one asked for a 29er Enduro. At least, I never heard anyone ask for one. Most long-travel 29ers of the era had all the handling grace of shopping carts. The 26-inch wheeled Enduro, by contrast, was a low-slung, nimble bike with a long top tube and a short rear end. That formula is all the rage these days, but it had been a hallmark of the Enduro for a decade by this point. Adding 29-inch wheels to that formula? It didn’t make sense. But Specialized did it anyway. Amazingly, it worked out.
Specialized wasn't first to market with a long-travel 29er, but they broke molds with this one - which featured a much shorter rear-end, and it changed a lot of peoples' perceptions of what a 29er was capable of.
“I still remember the exact moment when Brandon Sloan told me to stop working on the 26 version and get a 29 version into production. And it had to have all the same geo as the 26 bike,” recalls Jason Chamberlain. “I just sat there and deflated in my chair as the reality hit me. Short chainstays with wagon wheels simply weren’t possible with existing front derailleur technology, and 1x had not taken over yet. I had to get really creative and convince SRAM to partner with us. I had to design a front derailleur mount that was easy enough that SRAM could get on board.”
The end result, however, was stunning: A 29er with 155 millimeters of travel and 430-millimeter (16.9-inch) chainstays… Many riders climbed aboard expecting to hate the thing and wound up eating crow instead. Make no mistake, a new crop of nimble-yet-capable 29ers was already sprouting up, but the Enduro 29er was the most extreme and innovative of them.
And yet the wheelsize that many riders wanted was neither 26 nor 29: They wanted an Enduro with 27.5 (aka “650b”) wheels. Though plenty of Specialized engineers personally preferred the wagon-wheeled Enduro, the company released a 27.5 version as well in 2015.
This Year's Model
And here we are…looking at the new Enduro, which makes its debut today. For 2017, Specialized refined, rather than reinvented, the Enduro.
The latest Enduro receives a modest bump in suspension travel and several tweaks aimed at upping the ante on frame stiffness and reliability. The most obvious change, however, is that there are now Enduros that mesh with every wheel size, including, you guessed it, 27-plus.
• Lifespan: Time will tell
• Design intent: "Do it all. From steep, root-laden climbs to white-knuckle descents."
• Frame material: Full-carbon models, carbon/aluminum and all-aluminum models
• Fork travel: 160 millimeters (6.3 inches) in 29/27+ and 170 millimeters (6.7 inches) in 27.5
• Rear wheel travel: 165 millimeters (6.5 inches) in 29/27+ and 170 millimeters (6.7 inches) in 27.5
• Geek facts: Press-fit bottom brackets go away, SWAT storage door arrives. Two frames (29/27+ and 27.5) allow for three wheel options.
Fatter “plus-size” tires are making their way into more and more bike lines and they show up here as well. For 2017, Specialized is offering a line of Enduros that play nice with both 29 and 27-plus (what Specialized calls “6Fattie”) wheels and tires. The chassis is designed on a 29er frame platform “with tire clearance and wheelsize options as a consideration.” In other words: you can fit both 27.5x2.8 tires and 29x2.5 inches tires in the thing.
Still hate wagon wheels and you’d rather burn in hell than rock a set of 2.8-inch tires? If that’s you, you’ll be glad to know there’s also a complete line of Enduros specifically designed around “normal” 27.5-inch wheels. You can fit a 27.5x2.6 tire in that sucker if you are sorta plus-curious.
When it comes to new-bike launches, reliability and utility tend to get short shrift in favor of bells and whistles. Not this time. The 2017 Enduro receives larger linkage hardware and bearings, improving stiffness and reliability. Boost 148 also shows up this time around. Specialized improved the Enduro's Internal cable routing, adding independently-molded tubes within the down tube that should reduce fist-shaking and cursing at the heavens when it’s time to run a line through the frame.
The rat’s nest of cables that always hung beneath the Enduro’s bottom bracket is gone. And speaking of bottom brackets, the press-fit bottom bracket that took root on the Enduro in 2013 is, thankfully, banished and replaced with a threaded bottom bracket. Finally, if you always felt that the Enduro desperately lacked a burrito storage unit, there’s a new SWAT utility door on the down tube.
How will the latest Enduro fare over the long run? We'll see. In the meantime, Tech Editor, Mike Kazimer, has spent some time aboard the bike and has this to say about it.