Frame: 2011 Specialized SX with a PUSH tuned shock, built up with 2010 Fox RC2 Float fork Truvativ Holzfeller OCT cranks and BB, Mavic 721 rims built on hadley hubs and straight gauge spokes, Sunline bars and stem, X9 drivetrain, Saint brakes, and various dh tires (Kenda 2.35 BBGs in the pics). Other than tires, some Time clipless pedals, and a Fox air volume reducer in the rear shock, the same build that I used for dirtjumping.
Intended Use: Four cross, Slalom, Slopestyle, Dirtjumping, General jumpy mayhem
Geometry Chart: Specialized SX Frame
Rider: 5’8”, 160 lbs. of stocky, pissed-off chihuahua, with about a decade of DH, 15 years of XC, 7 years of dirtjumping, way too much digging, and a love for speed over any and all terrain.
An inevitable question in many peoples’ minds regarding bikes like like the Specialized SX is: How does its construction and geometry translate to performance out in the woods? The term ‘mini-dh’ bike gets thrown around a good bit, and it’s pretty apt. These shorter travel (4”-‘ish) frames are built for jumping, hard landings, and high speed cornering, so they tend to be stiffer and more durable than most xc/trail bikes.
I typically have at any given time a dh bike, a trail bike, and a seven inch travel bike built up with burly components. To gain the mandatory elevation for happypants™, the dh bike rides chairlifts, I pedal the trail bike, and my truck usually shuttles the seven inch bike—though an occasional climb does get thrown in there. I sold my seven inch ‘freeride’ bike this year with the intention of using the SX frame on all the same trails, features, rocks and jumps, just with a lot more sprained wrists, ankles and faceplants in the mix.
I installed wider bars, clipless pedals, and some dh tires, and literally left everything else the same as when I take the bike to the jumps. (See part one for the general build.) I dropped the rear shock pressure to about 190psi, the Fox air fork to about 70psi and went for some rides. I got some good days riding lifts at Northstar (on most of the same trails I normally take my dh bike down); riding some long, dirt road climbs to singletrack descents; and taking some fun shuttle laps.
When I could see well enough to know where I was, I had a great time doing all of the above. The dh tires alone gave me enough confidence to beat the living crap out this bike and stuff it so hard into corners I thought tire knobs would be hitting me in the face. The rear end felt great, but this is also where the harsh reality of riding a 4” travel fork made itself well known. At the end of some 4-5 minute descents at full speed, I had a few moments where I wasn’t sure if I was going to be able to hold onto the bars long enough to finish the ride before putting some teeth imprints on my stem. I cranked compression damping settings with low air pressures, backed off compression settings with higher air pressures, ran zero compression damping with low pressures, and nothing was matching the relatively supple rear end of the bike. It’s not often that my one answer to a problem is simply ‘more travel’ but a 4 inch travel fork just does not compliment this frame when it gets rocky. I said it before, but this really is like a 5 inch travel, 4 inch frame. It just rides that way.
One of my biggest gripes I discussed in my initial review of the SX was that the frame is not at all suspended like a dirtjumper/slopestyle rig should be. With the stock shock, it readily blows through its travel on big jump faces, even at shock pressures approaching 300psi. At those pressures, the rebound circuit is way overtaxed and I was still getting an overly bouncy ride. A tune by PUSH suspension upped the compression and rebound damping range, but the owner, Darren, still didn’t seem to believe that what I wanted was a more progressive feel from the rear end. They did the tune, threw in a bottom out bumper (which does in fact take up some air volume in the chamber), and told me to try it out. I did.
I still wanted a progressively sprung feel from the bike. After my first review hit the intertubes, a kind soul pointed me to something that Fox Suspension just made available to the public: behold the air chamber volume reducer kit.
Fox sends these ‘kits’ out with three spacers, small, medium and large. You can probably figure out which is which.
With the bottom out bumper already taking up space in the PUSH tuned shock, I went with the medium spacer in that one, then stuck the largest spacer in the stock shock that came with the frame.
Here’s a pic of what they look like installed.
With the medium spacer installed in the PUSH tuned shock, my Fox fork bumped up to 130mm travel, and I had high hopes I’d finally dialed this thing in. Good god is it dialed in now! Settling at about 50psi in the fork and about 185psi in the rear shock, this bike finally felt balanced and ready to hit things, and hit things I have. It doesn’t have the travel of a full blown dh bike, and not really even the travel of a modern trail bike, but this has got to be one the stiffest and sturdiest bikes I’ve ever taken down rocky singletrack. Mini-dh bike indeed.
With a 130mm tapered steerer Fork (meaning a big fat external 1.5 headset on the bottom), and some moderately sized dh tires (think 2.5 Maxxis Minions), my bike is sitting with a 65 degree headangle, and a 12.5 bottom bracket height.
I can’t even type that without grinning.
Let those two numbers sink in a bit. Every high end trail bike should come with measurements like that, and it’s a damn shame that so few (if any) do. I’ve pedaled this bike up rock gardens, long, fire road grinds, and plenty of loose, dusty, skidder paths down the center of a trail. It works. It just does. I didn’t have a single day ‘ruined’ by hitting my pedals on anything or looping out onto my back, squirming around like a turtle some teenager flipped over to play spin the bottle.
Having said that, I’m not the kind of rider who uses the term ‘dab’ or loses sleep over ‘making’ some steep rocky climb. For those weird, overly-spandexed guys with body armor and an xc lid who throw temper tantrums and fling their bikes around when their rear tire slips while climbing, or when they hit their foot on a rock because they haven’t figured out pedal timing yet, those numbers might be scary. For those of us who want a burly descender that you can also climb on, let’s embrace them, eh? Because those numbers are good. Really good. The thing just rails turns, banked, flat, whatever, and definitely has the stiffness to back it up. If you’re familiar with any of the recent Demo or SX trail frames Specialized is making, you know the burly clevis style pivots and big over-sized aluminum hardware they use. They’re present on this frame as well, and do a good job of helping the frame ride very sturdily.
Configured as a trail bike, the SX (can we call this one the trail SX?) is quite good either with or without the Fox Shox volume reducer. It’s really plush without, and a little more poppy with. If you’re considering this frame for trail duties, I’d recommend that you try both setups. The kit is only about 20-25 bucks, so it’s no great commitment. If I’d had this kit before taking it out dirtjumping, I’m not sure I would have bothered with the PUSH tune other than to maybe boost the rebound damping capacity. The PUSH tune gives you a much greater range in the 3 ‘propedal’ settings so if more low speed compression control is something you think you need, go for it. But for the sake of your wrists, start out with a 5 inch travel fork. It’s a much better match than trying to go straight 4×4. Contrary to what many of us males hear (not me, of course), an extra inch can in fact make a huge difference. I’ll be riding the fork at 4 inches for jumping, but never again anywhere it’s rocky and fast.
One thing I didn’t do that some might be curious about is put on a front derailleur. Honestly, I didn’t really want to because I enjoy a cleaner setup if I can use it. I never had any plans to take this out on 3+hour climbs, and with a 36t front ring, an 11-28 cassette got me around without too much trouble. I got plenty of seated spinning, quite a bit of standing climbs and some good sprinting on flatter sections and feel comfortable saying the bike pedals as well as most of Specialized’s other current options. There’s a miniscule amount of motion in the suspension but it doesn’t squat like a lot of their bikes did in the past and what does occur is easily managed with the current shock damping options.
Summing up this bike has gotten a little easier for me after (1) becoming aware of the air shock volume reducers and (2) getting it away from jumps and into some rocks. I’d say of the slopestyle/4x/dirtjumper suspension bikes out there, this is the most mountain bike-esque one that I’m aware of. I’m as much of a mountain biker as I am a jumper, and I’m really pleased with that aspect of this thing. Before hitting the woods, I was seriously considering selling it and just getting a different frame because I honestly wasn’t that happy with how it performed hitting big jumps at speed. With the volume reducer kit, the bike is much more in line with what most people would consider a bike built for jumping.
I think about the only thing I’m going to try changing at this point is putting on a 1 ⅛” steerer fork just to ditch the big bottomed 1.5” headset and lower the front end. It should quicken up the steering in the jumps and not have too much of a detrimental effect on singletrack. Other than that, I’m pretty happy to say that I now consider this bike a keeper in all respects.