The Takeaway: The 15th generation of the Stumpjumper is Specialized at its very best. It is a superb, highly refined bike featuring unique ride-enhancing technology in the deceptively simple Genie shock. This bike does everything it is supposed to do and does it extremely well. The Stumpjumper is the new benchmark trail bike.
Specialized’s Stumpjumper is iconic. As the first production mountain bike, the Stumpjumper started a revolution in cycling when it debuted in 1981. As mountain biking developed and progressed over the decades, the Stumpjumper changed along with it. Specialized reinvented the Stumpjumper many times with different materials, new wheel sizes, disc brakes, and front and rear suspension to meet mountain bikers’ riding wants and needs.
Today, we see the launch of the latest generation of Stumpjumper, featuring an interesting new shock technology called Genie. By Specialized’s count, this new bike is the fifteenth generation of the full-suspension Stumpjumper platform (hence, it is dubbed Stumpjumper 15). The new bike is the best and most capable Stumpjumper the Morgan Hill, California-based brand ever produced.
And the Stumpjumper 15 is, so far, the best trail bike you can purchase in 2024.
What is Genie?
It’s not immediately apparent, but something interesting is happening inside the new Stumpjumper’s shock. As Specialized states in the bike’s press kit, “Compared to other air shocks on the market, Genie allows for a lower spring rate earlier in the stroke, with a higher ramp later in the ending stroke.”
It attains this with a custom two-stage air spring developed in-house at Specialized. While Fox manufactures the shock, Specialized has patents pending on this system. This allows Specialized to potentially have the Genie spring built into any brand’s air shock.
Specialized isn’t the first to tinker with a multi-stage air spring. Trek’s DRCV (dual rate control valve) from more than a decade ago was a two-stage air spring built into some shocks and even a few forks. But the DRCV air spring volume was initially smaller before switching to a larger-volume air spring partway through the stroke: Genie is exactly the opposite.
For the first 70 percent of the shock’s travel, the Genie air spring consists of the volume inside the main air chamber plus the air sleeve volume surrounding the shock body. This air sleeve is also referred to as the XV (eXtra Volume) sleeve.
At 70 percent travel, a ring on the air piston blocks off the ports that allow the main air chamber to communicate with the sleeve’s air chamber, reducing air volume to only what remains in the eyelet.
And…that’s really it. The Genie’s air spring volume is extra-extra-large for this first 70 percent of travel but reduces to that of a standard air shock for the last 30-percent.
It’s hardly even more complex with just a few more parts than a standard air shock. But while it’s a somewhat basic idea executed rather simply, Specialized is making some very grand claims about Genie’s benefits.
The short version is Specialized claims Genie offers the best of both shock worlds: The sensitivity of a coil spring but with the ease of setup, progression, low weight, and air volume tuning options of an air spring. The long version is found in a 15-page white paper that lays out—in great detail—how Specialized says Genie is better-er than any other shock.
The white paper states that, compared to a standard air shock, the Genie’s benefits include:
- 11.3 percent less bottom-out event time. (Defined as “The sum of all time spent with the shock fully bottomed out while riding.”)
- 57 percent less traction loss time. (Defined as “The sum of all times the rear wheel is slipping with respect to the front.”)
- 27 percent less traction loss intensity. (Defined as “The difference in the front and rear wheel speed when a slip occurs.”)
- 10.5 percent less chassis pitching. (Defined as “The speed at which the front triangle is bucked back and forth.”)
- 11 percent less uncomfortable vibration exposure. (Defined as “The amount of vibrations reaching the rider, specifically focusing on the range of frequencies that have been proven uncomfortable for humans to experience.”)
Another benefit of the Genie’s two-stage air spring is that it provides riders with a second tuning tool not available with a standard air shock. Not only is the end-of-stroke progression adjustable with volume spacers like most air shocks, but riders can also independently tune the air sleeve volume, influencing the feel of the spring in the initial stages of travel.
This adjustment allows riders to make the suspension initially supple or poppy without influencing the progression at the end of the travel. Likewise, riders can make the end-of-stroke progression soft and linear or ramp aggressively without altering how the suspension feels at the beginning of its travel.
For more insight into the Genie shock, see my Q&A with Chance Farro, Specialized’s Suspension R&D Manager, below.
Features and Details
For this generation, Specialized not only made a new bike, but the brand also reoriented its trail bike lineup. The outgoing Stumpjumper line consisted of two bikes: the Stumpjumper with 130mm rear travel (with a single pivot/flex stay design) mated to a 140mm fork and the Stumpjumper Evo with 150mm rear travel (using a four-bar Horst Link design) and a 160mm fork.
The new Stumpjumper 15 has 145mm of rear travel via Specialized’s signature four-bar Horst Link system, mated to a 150mm fork. This model supplants the 130/140mm Stumpjumper and the 150/160mm SJ Evo.
“The goal was to take the best attributes of Stumpjumper (snappy and nimble) and Stumpjumper Evo (capable and adjustable) into one platform that catered to a wider range of riding styles and terrain,” said Todd Cannatelli, Specialized’s mountain program manager.
I asked Cannatelli how Specialized settled on the 145/150mm combo. He responded, “The rear travel number can be a bit deceiving [on Genie-equipped bikes] as we are using more travel than a standard shock for a given force in many instances. The total travel of the bike is 145mm, but that number is not an apples-to-apples comparison to a bike without Genie.” Cannatelli added, “We of course tested with different fork travels, but we ultimately felt the bike was the most balanced with the Genie shock and a 150mm fork.”
Despite featuring less travel front and rear, the SJ 15’s geometry changes little from the outgoing Stumpjumper Evo (more geo details below).
For riders who crave a lighter trail bike—like the old 130mm Stumpjumper—I suggest checking out the new Epic 8 Evo. For riders craving the more gravity-oriented vibe of the old Evo, Specialized offers one Evo-ish model—the SJ 15 with a 160mm fork and a burlier build (see the models and prices section below for more info).
Cannatelli said the new Stumpjumper 15 frame is about 15 grams lighter than the old Evo (so, it’s closer to the Evo than the weight of the outgoing 120mm Stumpy) while maintaining the same stiffness and strength properties as the Evo frame.
Unlike many Specialized models, the S-Works Stumpjumper 15 is not a wholly different frame. It gets the same FACT 11m carbon designation as the less-expensive models, but the S-Works model uses a carbon link that saves a handful of grams.
Specialized claims the complete, ready-to-build SJ 15 frame with Genie shock in size S4 weighs 3,007 grams (6.6 pounds), which is quite light for a trail bike frame. The carbon link on the S-Works frame saves about 60 grams (0.13 pounds).
My second-from-top Pro model in the S3 size weighed a hair over 30 pounds without pedals, which isn’t bad for a modern trail bike with an SRAM Transmission and Maven brakes.
One of the most obvious visual changes is the elimination of the “sidearm” of the old frames that bridged the top tube and seat tube. This results in a cleaner and more traditional-looking frame. The seat tube was also reshaped—it now has a more abrupt and lower kink that increases the length available for seat post insertion. This should allow many riders to use a longer-travel dropper post.
Specialized also graced the new SJ with its latest execution of SWAT in-frame storage. Like the new Epic 8, the Stumpjumper gets a flush-mount, more waterproof door with a finger-friendly release lever.
Most models and sizes run 29-inch wheels front and rear. For riders who want to run an MX setup (see exception below), Specialized sells an aftermarket link ($75) that corrects geometry and kinematics to match the bike with dual 29-inch wheels.
All sizes of the Ohlins Coil model come from the factory with a 27.5-inch rear wheel and conversion link installed. If you buy one of these MX bikes and want to swap to a larger rear wheel, Specialized also sells the 29er link for $75.
The wheel size story for the two smallest sizes—S1 and S2—is somewhat different. These sizes are “only compatible with a 27.5 [inch] rear wheel so we could optimize the rear center and geometry for shorter riders to maintain the ride quality we wanted,” said Cannatelli.
As for kinematics, Specialized made a few refinements compared to the outgoing Evo. Some of them relate to optimizing suspension performance around the Genie shock (see the Q&A section below for a bit more on this), but it also decreased anti-squat slightly compared to the old Evo.
Putting a bow on the details, the SJ 15 runs a 34.9mm seatpost, BSA bottom bracket, ISCG ’05 tabs, and a UDH (universal derailleur hanger). Also note that this frame is only compatible with electronic drivetrains: If you prefer to ride battery-free, you’ll likely need to wait until the inevitible aluminum frame Stumpy 15 appears.
The new SJ also gets protected by Specialized’s new “lifetime, no-questions-asked, bearing replacement policy.” So feel free to ride through all the streams and blast it with a pressure washer.
Geometry
I won’t get much into the weeds with specific numbers because most of them are in the geometry tables (one for SJ15 with a 150mm fork and one for the Ohlins Coil model with a 160mm fork) I’ve pasted here. However, although it runs slightly less travel front and rear, the SJ 15’s geometry is almost identical to that of the outgoing SJ Evo.
All SJ 15 bikes and frames ship with an accessory drop-in upper headset cup. This alternate cup provides +/- 1.0 degrees head tube angle adjustment (the geometry table shows the bikes as shipped with the middle cup installed).
Meanwhile, flip chips in the chainstay links offer +/- seven millimeters of bottom bracket height adjustment and +/- 0.5 degrees head and seat angle adjustment (bikes ship in the high mode). All told the head angle ranges from 63 degrees (slack cup and low BB setting) to 65.5 degrees (steep cup and high BB setting).
The seat angle is size-specific, but the geometry chart for the bike with a 150mm fork listed above is incorrect. When I questioned why the S3 was steeper than both the S2 and S4, Cannatelli confirmed it was an error on Specialized’s part and sent over the correct effective seat angles, along with the saddle height those angles are taken from (Lower saddle heights result in a steeper effective angle, while taller yields a slacker effective angle).
The correct seat angles are:
S1 - 78 degrees at 645mm saddle height (center of bottom bracket to the top of saddle)
S2 - 77°, 690mm
S3 - 77°, 735mm
S4 - 76.5°, 780mm
S5 - 76.5°, 825mm
S6 - 76.5°, 870mm
There are four chainstay lengths for the six frame sizes. The S1 gets 430mm stays, while the S2 runs 432mm. Sizes S3 and S4 share 435mm stays, while the S5 and S6 share 445mm stays.
Note that geometry is largely the same whether the bike runs a 27.5- or 29-inch rear wheel, so long as the frame is fitted with Specialized’s wheel-size specific upper suspension link.
Models and Prices
The new Stumpjumper arrives in five complete variants priced from $5,500 to $12,000. Specialized also offers the Stumpjumper 15 as an S-Works frameset.
S-Works Stumpjumper 15 - $12,000
Stumpjumper 15 Pro - $9,000
Stumpjumper 15 Öhlins Coil - $8,500
Stumpjumper 15 Expert- $6,500
Stumpjumper 15 Comp- $5,500
S-Works Stumpjumper 15 Frameset - $3,500
While the outgoing Stumpjumper was offered in both carbon and aluminum frames, the new generation, at launch, only comes in carbon. However, there are strong hints that an aluminum frame might arrive later this year.
Specialized Stumpjumper 15 Models and Prices
Four of the five complete bikes run a 150mm Fox 36 fork (the smallest S1 size uses a 140mm fork) with the Fox Float Genie shock. All Genie shocks have a climb switch and three-position open mode damping adjustment. These models also feature 29-inch wheels front and rear, SRAM Maven brakes (200mm rotors front and rear for most sizes; the two smallest sizes run a 180mm rear), SRAM Eagle Transmission drivetrain (the least expensive Comp model gets the new, OE only, S1000 Transmission rear derailleur), rims with 30mm internal width, and a Specialized Butcher front tire with the sticky T9 compound mated to an Eliminator rear tire with faster rolling T7 compound.
The remaining variant is for riders who want something more gravity-oriented. The Stumpjumper 15 Ohlins Coil features an Ohlins TX 22 M coil shock with a 160mm Ohlins RXF38 M.2 29 fork. This model also has a 27.5-inch rear wheel wrapped with a heavier-duty Grid Gravity casing tire, TRP DH-R Evo brakes with 220mm front and 203mm rear rotor, plus a 35mm long Deity stem. This model is not offered in the S1 size; it is only in sizes S2 to S6.
Ride Impressions
I found Genie’s performance impressive. It is extremely—and remarkably—sensitive. And it is supple exactly when you want it, yet with superb support and plenty of bottom-out progression.
All the potential drawbacks I fretted about—Would it feel too soft? Would it wallow and feel like it sits in the middle of the travel? Would it feel like the suspension hits a wall when the sleeve volume gets cut off?—never materialized. Props to Specialized, Genie is sorted. And the resulting performance of the new Stumpjumper is superb.
But Genie’s performance isn’t in your face. Overall, the bike doesn’t feel radically different from a well-executed and properly set up suspension bike. But you will notice that the rear suspension has all the benefits of really plush suspension without the drawbacks.
While the Genie effect may be subtle, it feels like Specialized comes closer than any other brand in realizing the suspension feel and performance that we’ve chased since, well, since suspension bikes were invented. And that’s essentially the ride of a coil-over shock initially with the performance of an air shock in the later stages of the travel.
It’s not just that the Genie is only great at smoothing chunder and sucking up big bucks, either. It works great everywhere: More traction, more control, a more stable chassis, and a smoother ride. It simply works. And it’s not fiddly, complex, or heavy either.
Plus the Genie doesn’t require proprietary mounting bullshit or a weird frame design. It hardly looks different than any other shock. It’s hard for me to think of a technology I’ve found so impressive on the trail yet has so little extra baggage.
However, based on a quick spin around the parking lot, many riders' first impressions will be that the Genie shock is too squishy and linear. Therefore, riders will assume it to be wallowy and bottom easily on the trail. The danger is these riders may feel that the suspension is “too soft” and try to air it up or reduce air volumes to make it feel more like a traditional air shock.
But don’t—leave the stock volume spacers in place, set the shock at 30 percent sag (16.5mm on the shaft), and ride a favorite trail. You’ll be surprised at how supportive and bottom-out-resistant the “too soft” shock is on the trail.
Many of the claimed benefits of Genie are the same as those of Cane Creek’s Tigon hybrid coil/air shock (about $1,000 with spring and hardware). In Specialized’s favor, though, the Genie is realized in a much lighter, more tunable, and sleeker package. Plus, it is custom-tuned specifically for the Stumpjumper. But if you can fit a Tigon on your bike, you should experience at least some of the performance benefits of the Genie-equipped Stumpjumper 15.
Between the lower anti-squat and the softer spring of the Genie, I expected the Stumpjumper’s pedaling performance to go out the window, and I imagined using the shock’s climb switch often. But that wasn’t the case at all. I was quite impressed with how efficiently the new SJ pedaled and how little bob I experienced. Much like its performance over bumps, this bike is settled and quiet when pedaling.
However, it is not an especially fast climbing bike, and it doesn't feel particularly swift on flatter trails (I suspect at least some of this is due to the sticky rubber front tire). The Stumpjumper pedals along well enough, but it doesn't have the crisp acceleration of a Pivot Switchblade, for example.
While the Genie shock is the Stumpjumper 15’s biggest story, there is much more to this bike. To be clear, this is not a great bike because it has Genie; it is a great bike, and it has Genie.
The chassis is superb. It feels robust and well-tuned, stout but not overly stiff. The geometry works well for a wide range of trails. The geometry (and shock) have enough adjustment options to fine-tune the bike for many types of riding—even occasional visits to the bike park. (However, the SJ 15 would not be my first choice if I knew I would be riding in a bike park a lot.)
Notably, the Stumpjumper 15 is a better daily driver than the old (and very good) SJ Evo. The old Evo’s vibe is enduro-adjacent and needs a bit of speed and steepness to feel its best. The new SJ has almost the same capability on the most challenging trails but feels faster and more agile when riding less extreme terrain, which makes the new bike more entertaining to ride across a wider range of trails.
If you find the new Stumpjumper is not quite enough bike for your steep and challenging terrain, it can be easily optimized for rowdy trails with its geometry adjustments. Riders can use a 27.5-inch rear wheel and drop in a new air spring to bump fork travel to 160mm. But if that’s what you need for your daily driver, buy the SJ 15 Ohlins coil model—it’s basically an improved version of the old Evo.
And since the new Stumpjumper has no weird standards, this bike will be easy to live with for a long time. Even if the future reveals some huge flaw with the Genie shock (I don’t see that happening, but who knows?) it has standard dimensions and mounting eyelets. So, owners can easily source a different shock for this frame.
I’m annoyed at Specialized because the Stumpjumper 15 is so well executed that it’s giving me nothing to complain about. All I got is that the textured finish honestly looks like there was an error when the painter tried to apply the clear coat.
Is the new Stumpjumper 15 with Genie the best trail bike available today? I don’t think one needs to try hard to make that case. This bike is dialed. But there are many great trail bikes on the market from brands big and small. I could list a dozen or more other trail bikes I’d happily ride. However, if you forced me to pick a single bike today, I’d go with the new Stumpy.
Notes from the Field
Random observations and reports from my time testing the bike.
• The Pro model I tested features a textured finish that I’m unsure about. It looks like the painters messed up the clear coat or the frame is covered in dried drink mix. No joke: One of my riding buddies asked if a soda can exploded and sprayed the bike. When covered with a clear frame protector, it looks like hell, with bubbles everywhere.
• I’m, again, going to mention the super long saddle clamp bolts employed by Bike Yoke. It’s extra concerning in this case because Specialized’s saddles are quite low profile, and the top of the bolts sit mere millimeters under the saddle shell. I’d suggest everyone (carefully) find shorter bolts or chop the stock bolts. I love the function of the Revive dropper, but Bike Yoke needs to refine its saddle clamp.
• The headtube angle adjustment system consists of just a drop-in upper headset cup and requires no tools to change. It’s extremely easy to swap—easy enough to be done trailside if you’re so inclined.
• Swapping the air sleeve and eyelet volume spacers can be done with the shock installed in the bike. However, I found the air sleeve very difficult to slide off the first time I tried—I needed to remove the shock from the bike to get a good enough grip to dislodge it. However, I successfully removed the sleeve with the shock mounted in subsequent attempts. Accessing the eyelet volume spacer may require a strap wrench.
• The Roval Traverse wheelset on my Pro test bike is very good. I’ve had a pair in for long-term testing before I received this test bike, and they’ve been trouble-free. I like their blend of lateral stiffness and vertical compliance. They also appear to be very good at warding off flats: I’ve rimmed out multiple times on both wheelsets with no flats (so far).
• The Traverse rims on my Pro test bike are laced to Industry Nine’s 1/1 one hubs (lighter than i9’s top-of-the-line Hydra but with slower but still speedy four-degree engagement). A US-made machined i9 stem complements the hubs. Both are nice little premium touches.
• Specialized launched the Mimic saddle padding in 2018 as a product specifically designed for women’s anatomy. Specialized has since found that all riders, no matter their anatomy, find the padding comfy and specify Mimic saddles more broadly. The Stumpjumper 15 Pro model I tested has Specialized’s Bridge saddle with Mimic, and damn, is it comfortable.
• SRAM’s Maven brakes are heavy and ultra-powerful. Are they too much brake for this bike? I’m sure some riders will think so. But while the SJ would be marginally lighter with a less powerful brake, I loved having the easy-to-modulate power and consistency of the Maven.
Q&A with Chance Farro
Specialized’s Suspension R&D Manager
This interview was edited for clarity.
Matt Phillips: I'm going to start with: Briefly explain Genie.
Chance Ferro: I guess the brief answer is what actually the technology is: A dual stage air spring. On the positive side, we have one large volume that we then cut into two chambers, basically creating a secondary spring ramp.
Matt: What are the benefits to the rider?
Chance: It started with playing with really [air] large volume, and really, the benefits were basically taking progression out of the spring, flattening out the spring curve, getting more usable travel, and kind of exploring that side of things. But then, of course, running into bottoming issues and lack of support and all that that you have with less progressive bikes and springs.
And then that’s where the Genie technology comes in to allow us to have the big volume, but then also get the progression and spring ramp back that we needed.
Matt: And what is the benefit to that big volume?
Chance: So the big volume provides more suspension used per bump, giving us more traction, more better bump compliance. It's a softer spring in that earlier part of the stroke that just tracks better. [It] acts like a longer travel bike in those zones, just overall smoother ride.
Matt: Okay, so all air springs are progressive. So how is Genie different than a standard air spring?
Chance: The Genie air spring is basically both linear and progressive, I guess you could say. And it's broken into different portions of the travel. From that sag point to 70%, we’re very, very linear.
It is kind of flat [like] a coil spring. It's not very progressive. And that’s what the big volume gives us, and that's kind of where we're getting those benefits and traction and all that.
And then at about 70% of the stroke, we create uber progression. It's even more progressive than your typical air spring at that moment where we need it. It’s giving us a Jekyll and Hyde kind of air spring.
Matt: Why is this approach better than using damping or kinematics to achieve a similar end result?
Chance: We’re using kinematics as well to kind of, like, blend it. So it definitely plays in with the bike. The bike is less progressive as well.
It’s pretty easy to make a less progressive bike or shock. But what was hard to do is create that Jekyll and Hyde feel. So we could either have progression or no progression. We couldn't have both with kinematics. All the kinematics are kind of on a swooping trend. Like, you’re gonna either kind of have a progressive setup or a linear setup. We couldn’t have one that aggressively changes. So that’s where this technology allowed us to do that.
Matt: It seems like Cane Creek's Tigon shock is touting many of the same benefits as Genie. What are your thoughts on this shock and why not just specify it on the new Stumpy?
Chance: Yeah, I’d say the Tigon's actually a really close reference to what Genie is doing. The idea of this secondary spring ramp using air springs is a similar idea, for sure.
Obviously, the big difference just being they’re using a coil, we're using complete air. I’d say, for what we're doing, [the Tigon is] quite heavy. It’s even heavier than your standard coil shock. So especially for a Stumpjumper, you know, it’s really important for us to have a lightweight shock.
So that’s probably one of the biggest differences. There’s also tunability. We love air springs for that. And then I will say, when you go to a shorter travel shock, coils actually become kind of challenging for some reasons.
On a short travel bike, you end up actually running a pretty stiff coil spring. So on short travel bikes, you can almost have a coil shock that’s too progressive, if that makes sense. So the combination of, say, like, a coil shock [with a secondary air spring] could be overkill. So, with, with what we’re doing, we're able to kind of maintain that sag and then still flatten out that spring curve with the big volume and then get the ramp so it plays well with kind of short to mid travel bikes.
Matt: Is Genie compatible with different wheel travels. Would it work on a 130mm travel Epic Evo or a 170mm travel Enduro?
Chance: Oh, for sure. Yeah. We’re definitely looking at things on our end. We’re excited about the technology.
We developed it for Stumpjumper in this mid-travel range. And we’re exploring where else it can go. We see a lot of potential for lots of different wheel travels, for sure.
Matt: How many extra parts in a Genie compared to a standard Float shock?
Chance: So we’ve added one sleeve, and then beyond that, it’s a piston band that lives on the main piston. That and a couple seals.
It might not be more than five parts with O-rings included, and most of those parts are: they’re kind of a reuse. There's already a seal head there, and we just modified it and made it work for us. So it’s a pretty surprisingly simple shock in that way.
Matt: The Genie is not a reservoir shock. Should riders have any concerns about heat fade?
Chance: Yeah, that was something that we wanted to check off. It’s a conversation even in our office. And so we actually did a study on heat fade between a lot of different rezi [resevoir] shocks and this inline shock.
And we did find that the [Genie] shock gets about 10% hotter. But when we actually measure the effect of the fade, it was actually no difference. So, essentially, if the [Genie’s] max temp was 180 degrees, the other shocks were at 170. But on the dyno, they didn’t fade any different based on that ten-degree difference.
So we feel really confident this thing will hold up against big rezi shocks and all that.
Matt: Is the suspension setup procedure any different when you get your new Genie-equipped Stumpjumper versus one fitted with a standard Float shock?
Chance: No. If you didn’t know this was a unique shock, you’d set up exactly the same way. Set your sag about 30%, and it’ll work great.
Matt: All right, so the Genie offers ability to independently tune initial spring feel and then end of stroke progression. How should riders use these tools to help dial in their shock based on rider weight, experience, and terrain.
Chance: I think it’s really more the latter. The kind of terrain they’re riding and the experience they want.
I don’t see people needing to change too much: The spring scales really well. It’s actually one of the benefits of this shock. The secondary ramp, it scales in accordance to the spring rate that you put in there. So heavy riders and light riders will have the same ratio of mainspring to the secondary ramp, which is not the case with hydraulic bottom outs or bumpers and things like that, where that secondary spring is kind of, you know, always set. So that's one benefit in terms of how you'd set it up for your riding style and terrain.
That’s where it gets pretty fun. We have a lot of cool adjustments. We now have two chambers that we can dial in the volumes of. The [outer air chamber volume] bands will affect the middle part of the stroke, and then the eyelet independently affects the end of the stroke. So really depends on what you want.
If you want, like, say, the most plush feel, you’re at a bike park or something, or really rough trails, you can take all the volume spacers out of that outer sleeve, and it’ll just feel really, really plush. That's the really big volume.
But you can still be a really aggressive rider with that setting. You can even then put the larger [volume] spacer in the eyelet. We've even seen some of our most aggressive riders loving that setup.
You can put that [outer] sleeve completely full and get a more poppy, snappy feel. It really does change the perceivable travel bike has.
Matt: Sort of related: What rider weight range is the stock tune designed for.
Chance: I’d say it’s no different than pretty much all of our bikes. From like 125 to 300 pounds. And a lot of that really is like dialing in the rebound range, making sure that we have a rebound setting that works well. The spring will scale even beyond that.
Matt: Are there different tunes for different rider weights or different size bikes?
Chance: Nope, they all come with the same tune. In the past we have done some size specific tuning. It was always on the rebound side just to make sure we can fit that in. But we were able to get a really nice broad range rebound adjustment so we're able to kind of fit it all in.
Matt: Shock service and service intervals: Are these any different with the Genie versus a standard Float?
Chance: Nope, it’s 100% the same. The procedure is slightly different, but if you know how to do an air spring service, it’s going to be a shoe in.
And yeah, as far as like who can service it? The same people that can service a normal shock. If you do it at home, you can do that. Shops and Fox will service them as well.
Matt: Is Genie suited to a suspension fork?
Chance That’s a great question. That's something that we're looking at right now. So I’d say it probably is.
Matt: Okay, cool. Will you offer Genie as an upgrade to other Specialized models? Like previous generation Stumpjumpers?
Chance: Like I said, we are still looking at it for other models and things like that. As far as aftermarket stuff, there’s no plans currently, but I think maybe some of the product managers and things, they’re looking at that because they’ve got a lot of questions. If there’s a demand for it, there’s potential for sure.
Matt: And what about riders who might not have a Specialized bike? And like, hey, I’d really like Genie on my bike. Is that, is it too bad: Gotta buy Specialized?
Chance: That's the current setup. But I mean, I would love to see if someone wanted to pull this off and put on something else. I'd be flattered.
Matt: All right, so this is kind of my final question. It’s got a bit of a long preamble. Stay with me here.
I feel like, as an industry, we’re still trying to educate riders on how to set sag properly and how to dial in rebound.
I’ve ridden Genie and I think the effects are there, but they’re pretty nuanced and subtle. And I think it'll take a somewhat savvy rider who's attuned to the finer points of suspension to really feel those differences on the trail. And it’s not something you’ll feel on a parking lot test ride.
Do you at all worry that Genie’s performance differences and benefits might be lost on some riders?
Chance: I don't think so.
If you’re looking at the tuning aspect of it, I think that's something that we're not really pushing. The tunability. I think the tunability we look at kind of like the head angle adjust on Stumpjumpers and all that. It's there for the really discerning riders that want to get into that level. But we basically wanted the shock to be as good as it could be out of the box.
So, like, the way it comes is our preferred tune. It’s really the point of view of the bike, and we feel it just basically is a holistic, great ride as a whole bike. So I don’t think you really need to get into the nuances to appreciate it and just basically have the best Stumpjumper we can have.
A gear editor for his entire career, Matt’s journey to becoming a leading cycling tech journalist started in 1995, and he’s been at it ever since; likely riding more cycling equipment than anyone on the planet along the way. Previous to his time with Bicycling, Matt worked in bike shops as a service manager, mechanic, and sales person. Based in Durango, Colorado, he enjoys riding and testing any and all kinds of bikes, so you’re just as likely to see him on a road bike dressed in Lycra at a Tuesday night worlds ride as you are to find him dressed in a full face helmet and pads riding a bike park on an enduro bike. He doesn’t race often, but he’s game for anything; having entered road races, criteriums, trials competitions, dual slalom, downhill races, enduros, stage races, short track, time trials, and gran fondos. Next up on his to-do list: a multi day bikepacking trip, and an e-bike race.
