Specialized StumpJumper FSR 29er Carbon vs Aluminium Review

by FatBob on July 5, 2012

The Specialized StumpJumper FSR is one of 29erOnline’s favorite bikes. We loved the 2010, WriterBob owns a 2011 Expert model, and, with the changes that were introduced for 2012, I had all the excuse I needed to get another one to test.

The 2012 Stumpjumper is a different bike from what we tested in 2010. Up front, it has a 130 mm fork instead of a 120. It comes with a heavier duty, trail build and the Comp models come with a Specialized Triad shock with Autosag. The 2010 model we tested had the Brain shock, was a bit lighter feeling, and, while plenty capable, wasn’t as at home on technical terrain as the 2012 version. One thing that hasn’t changed is how good the StumpJumper FSR 29er is. It rips, and remains a well loved bike with all of us at 29erOnline. We love what it excels at and forgive it completely for what it does just...good.

So what could better than a 2012 Specialized StumpJumper? Two Specialized Stumpjumpers! One with a carbon frame and one with aluminum. Until 2012, carbon and aluminum were not both an option at the Comp level. Now they are - the aluminum Comp model lists for $3,000 and the Comp Carbon lists for $4,100.

The gang at 29erOnline has been interested in really digging into the differences between carbon fiber and aluminum frames. The cost difference is pretty large - would the crew think it was worth the extra investment? With both frames available at the same component level -
Comp, we had a great opportunity to really zero in on the ride differences between the materials.

Answering the question; should you spend an extra $1,000 on carbon, or save the money and stick with aluminium, has been one of the most difficult questions we have wrestled with in our bike testing. To try to find the answer 2 riders spent many miles on each bike and came out deadlocked - dead even on if one was better than the other. So we got two more people and threw in a casual rider plus me to see if we could break the tie. In the end, I have a satisfactory answer, finally.

It isn’t worth spending a whole lot of time on components because they all do their job quite well. We have had no parts failures on our StumpJumpers. The mid level X7/X9 SRAM drivetrain is solid, reliable, and affordable. Sure, the upper tier SRAM parts are really awesome but, on the trail, none of us are unhappy with any of these drivetrain parts. As is our stance on most of these parts, as you wear it out, replace it with your dream kit. Just remember, it all wears out, even a dream kit, and will need replacing. With my money, I replace with the same level components.

The Specialized mini rise bars are wide, at 720mm. They have a 6 degree upsweep and a 10 degree back sweep. The upsweep, in my mind, makes it a true riser bar. Long term, I would recommend running the carbon version of this bar. It adds a bit more comfort. With 5 inches of front travel (130mm - if you must, 5.118 inches) you would think that it wouldn’t matter but I was surprised at how much I noticed the comfort added by my Easton Haven carbon bar on this bike. Incidentally, I prefer the Specialized bar’s dimensions. Most of the crew wanted to cut the bars down to their preferred size. It’s easy to do, but I would recommend riding it as is for a while before you commit to permanently altering your bar. The seatpost works great. It is simple and reliable. When other seatposts fail, I put on one of these stock Specialized seatposts, even on other brand’s bikes. They keep plugging away and make no noise. I do, however, suggest adding a dropper post. The Specialized Command posts we are running are flawless and have given multiple seasons of use. It changes the way the bike rides for the better, really unlocking all the potential of the StumpJumper FSR. If you can negotiate one into the price of the bike at purchase, go for it (it comes standard on the Expert level).

The stem is Specialized Pro Set II. While probably one of the ugliest stems I have seen (O.K., slight exaggeration), it works fine. I run 0 degree stems. It seems to me the angle of the stem was a bit too severe. I ended up playing with a negative rise and a couple of spacers to get the bar height correct. It gives enough versatility, combined with spacers, to get the job done but, in practice, I switched to my prefered 0 rise 70mm stem. This falls into to each their own territory. It may work for you, you may have to change based on fit. Make sure you work with your local shop to get comfortable on the bike.

The Henge saddle is the right combination of padding and support. It feels short but nobody that rode it complained. It is comfortable, and, while I prefer the more minimalistic Phenom, more riders will probably gravitate towards the comfort of the Henge. The back is rounded and easy to get behind and back and back over for great maneuverability. The Henge saddle comes in 3 widths. While at the shop, I recommend you try a couple of widths out, as your choice will be based on anatomy. Work with your shop to get the best saddle for you, then write a comment to thank us when you get the right size for your bottom.

The stock wheelset is a bit heavy, but solid for the bike’s price point. They can be run tubeless with a conversion kit. The Specialized tires are what Specialized calls 2bliss. These are some of the most reliable tubeless tires we have ridden. While the tires are made to run tubeless with a sealant, the rims need to be converted. I opted to use two layers of tape to help get the bead as tight as I could. They held air fine but you should proceed with caution. The Hi-Lo hubs are not as tight as I would like to see, but are appropriate for the price point. I hear some people complaining about these hubs online but we have not had any problems with them in several months of heavy use on any of our Comp model bikes. I prefer a higher end wheel (duh, who doesn't). This is the first place I spend my money when the time comes for upgrades. Specialized makes Roval Control Trail wheels, which we have been riding for months that really take this bike to the next level. Even wheels that aren't much lighter than the stock wheels, will roll smoother, be stiffer, and be more responsive to pedaling. So while, we have not had problems with the stock wheels, we will say that an upgrade, at some point, will pay dividends.

The Avid Brakes are strong and reliable - true one finger braking. The 200mm front rotor and 180mm rear (size Large bike) gives abundant stopping power. If you like going really fast downhill, you will appreciate the power and control the Avid Elixir 7 custom brakes.

Both versions of the Comp model have a PF30 bottom bracket. The “PF” stands for press fit and 30 is the bottom bracket spindle diameter. The bottom bracket bearings and plastic sleave are pressed into the Bottom bracket shell as opposed to threading in. On Calvin’s dream build of the Specialized S Works Epic we used an Enduro ceramic bearing set and it is super smooth and quiet. While the stock bearings on our Stumpjumpers are still working, they feel a little dry. There is definitely some drag. It is not at the point that I am ready to switch bottom brackets but it is still worth noting. I will take it apart and replace it but would like to see how far we can take them before I do. I’ll have to update this at a later date. So, while the jury is still out on the PF30 bottom bracket, it is undeniable that the bottom bracket area of the StumpJumper frame is solid, with no noticeable flex, even under hard, out of the saddle pedaling efforts.

The last item to look at is the fork. The StumpJumper FSR uses a Fox Evolution series 130mm, 32 mm stanchion fork with a 15 qr through axle. I can say first hand that the Rock Shox Revelation fork with a 20mm axle found on the EVO version of this bike is a stiffer fork. Even with the EVO’s extra 10mm travel, the stiffness and lack of twisting make it noticeably better. If using Fox Forks 34 model offers a stiffer platform, I’ll take the weight penalty tradeoff on this part of the bike. In my opinion, this was the only mistake on the StumpJumper FSR Comp model bikes.

From what I can gather, Specialized opted to use the Fox 32 platform for weight reasons. To be fair to the project managers making these decisions, budget also comes into play. However, from a performance standpoint, 32mm stanchions with 130mm travel is not stiff enough for an aggressive rider. I’ll tell you right now, the Specialized Engineers and project managers that I have met are better riders than me. Maybe this is why they can get away with less. I however, still feel that the fork is not stiff enough for this bike’s potential. For additional perspective, the test crew did not complain about the fork’s stiffness. However, they are all coming from a Trail and XC race background, so none of them pump the trail or generally bully a bike like I do. If you are a finesse rider, the Fox fork probably won’t be a problem. All that said, I will still stand behind my statement, and strongly believe that an aggressive trail rider will find the limits of the Fox 32 chassis sooner than later. Despite any weakness regarding the chassis, the fork’s action is plush, without being spongy and it offers enough mid stroke resistance to allow you to pump and hit jumps in control, with plenty of bottom out bumper for hard hits.

How does the StumpJumper FSR ride?

Climbing: The StumpJumper has a slack front end, and is tall because of the 130mm fork. Even so, it still barely wanders, even on the steepest climbs. Slide forward on your saddle, lower your chest and pedal. While we all agree that it isnt the fastest climber, we all enjoyed climbing on the StumpJumper. Line choices don’t have to be as picky. If you have some horsepower, the StumpJumper will mow over small to mid sized bumps. It pedals well, especially if you take the time to dial in your rebound. It is no Epic, but with the right rider it can still hang.

Cornering: The StumpJumper is confident in the corners. The suspension, combined with the 29er wheels, is so capable we find ourselves finding the best lines through corners, and not worrying about chatter. Switchbacks take extra care at first, but, once you get used to it, you can hit the tightest switchbacks on our trails with no problem. How good is good enough ? We have no issues with the StumpJumper in this area.

Descending: Fun, fast, stable, playful, confident. If the trail is pointing down, the StumpJumper rules. High speed, tech lines, pumping, jumping, the StumpJumper does it all. This is where slack angles come into play. It has to get really steep to not be able to steer and change lines. I have not found anything steep enough to challenge the Stumpjumper’s geometry.

Overall: The StumpJumper favors descending. What separates it from other long travel bikes we have ridden is that it does not sacrifice much anywhere on the trail. It is light enough and pedals well enough for long climbs, it is fun on flatter courses with flat corners and undulating turns. It is confident in technical terrain. It doesn’t do any one thing absolutely perfectly, but there is no type of trail we don’t like riding the StumpJumper on. Sure the Epic climbs better, and a downhill bike will descend better. The Camber is excellent and lots of fun on roller coaster terrain with opportunity for speed and air. However, none of the bikes do everything as well as the StumpJumper. If you can only have one bike and need to do a bit of everything, the Stumpjumper is our choice.

Carbon vs. Aluminium: Now is the hard part - the $1,100 question, you might say. Carbon or Aluminium? Carbon was unanimously picked as a better performer. It is stiffer, and feels easier to control. If we want to push ourselves, we pick carbon. The carbon bike accelerated better, and was incrementally more comfortable. The edge in comfort was a big surprise. However, although we all agreed it was a bit more comfortable, it was not enough to justify the cost (except Calvin, but look what he’s riding!) Carbon has a little bit more of a muted ride and it does not transmit as much numbing vibration. We had to really focus though to make this decision. The lighter weight of carbon was, again, noticed but it took a lot of riding before this became a factor. So less weight was significant and nice but it was not the selling point for us. In the end, overall handling performance was what made carbon fiber the winner. Maybe weight and added stiffness was the determining factor of why it handled better, a sum of all carbons attributes. Overall, the carbon felt like it accelerated more responsively and the steering was noticeably more precise.

Aluminium was not that far behind. We had to spend a lot of time to make up our minds that carbon, in fact, created a better performance machine. Remember, our kits were the same - everything was equal except the frame material. Us normal guys like aluminium just fine. It is good stuff and, on the Stumpjumper, it is stiff compared to the other bikes we have ridden. With the Stumpjumper’s 5 inches of travel, comfort is not an issue and, best of all, it is $1,100 cheaper. If you your budget is $3,000, buy the aluminum one and get on the trail. It rips. None of us would feel deprived if the aluminium one ended up in our garage. The difference isn’t enough to wait months to save up more and not be able to ride.

The wild card here is this: if you have $4,100 dollars to spend, should you buy the aluminum Stumpjumper FSR Comp 29 and use the $1,100 dollars you saved on a nice set of wheels. We are, again, split as a crew. Listen to the videos of the rider’s interviews. Paul says no. He liked the alloy fine. Jamie, votes alloy with nice wheels. Al and Calvin say carbon. Our beginners don’t notice enough difference to comment. I have ridden both bikes all different ways. My favorite is the Carbon with a nice set of Roval Control Trail wheels set up tubeless. Then, I run my Easton EA90 70mm zero rise stem with Easton Haven Carbon Bars. Finally, I run a Specialized Command post with a 5 inch drop and a Phenom Expert saddle in 143 width. Do the math on those upgrades! If I had to choose between the stock carbon bike or the alloy with the above listed parts, I go alloy. If you plan on upgrading parts over a couple of seasons with a generous budget, go carbon. Beginner rider? Alloy with a dropper post. Advanced rider - carbon with upgrades over time. Long term or short term? Ultimate in performance or just really good? This is the part where we let you make the decision that works best for your life.

{ 27 comments… read them below or add one }

tomas orts September 19, 2013 at 6:48 am

hello, now that you have tasted the giant trance x 29, could you give us an opinion on what improves on the stumpy 29 over the trance x 29? and trance x over the stumpy 29?
which do you like most?
Thanks and great job!!

Alfie July 22, 2013 at 12:49 am

Wow that was unusual. I just wrote an very long comment but after I clicked submit
my comment didn’t appear. Grrrr… well I’m not writing all that over
again. Regardless, just wanted to say excellent blog!

Igor July 2, 2013 at 12:04 pm

Thanks to this review (among others too of course) I finally made my decision and opted for Stumpjumper FSR Comp 29 2013 over 26er. I really hope 29er will deliver at my local forest singletracks as that was my only concern as they are pretty much tight. We’ll see I guess…

antimarx May 19, 2013 at 11:09 am

I average 1500 city street miles/year, year round [snow too].
I have a 29″ stumpjumper HT [speed wobble & a bone shaker], A Santa Cruz Blur LT[26″ & HEAVY], Kline Palamino [26″ & limited adjustability]
I want an efficient, LIGHT, 29″ full suspension bike.
Seems my choices are: Giant Anthem X 29, GT Sensor, Intense, Maverick, or a Santa Cruz Blur, all have rear suspensions designed for pedaling efficiency. [the Cannondale Scalpel is light, but the lefty shock lacks low speed compression adj.]
How about a weight comparison?

2nd question: What is the most supple 100mm or less fork, meaning SMALL bump compliance [like sidewalk & street cracks] for a XC bike? Most compromise ride for off road handling – I want street handling compromised for RIDE.

Robert March 7, 2013 at 2:35 pm

That’s pretty much what every review of recent year Stumpjumpers I’ve seen has said; that the Stumpy carries its weight well, and feels lighter than what you would expect when you see the results on the scale.

I sold my stock wheelset anyway, as I had a set of Stan’s Arch/Hope Pros that I had on my hardtail Niner that I swapped over.

FatBob March 7, 2013 at 6:08 am

Hi Robert, good question and the answer for all of us is easy. The Stumpjumper platform carries its weight very well. It does not feel as heavy as the Rumblefish. The Rumblefish feels tighter steering wise. The frame feels built sturdier and the suspension is purposefully stiffer at the begging of its travel. The StumpJumper is much more linear with a nice progression at the end. The Stumpjumper does not handle as quickly especially in slow speed situations. Neither bike bobs/bio paces/ wallows, when set up properly, excessively. The StumpJumper easily feels lighter although I would bet that the Rumblefish wheelset can handle more abuse and is better equipped for tubeless applications then the Comp model StumpJumpers.

Robert March 5, 2013 at 5:48 pm

Question about this alloy Stumpy Comp FSR compared to the Rumblefish you’ve just reviewed.

Now I bought a 2011 Stump Comp FSR, partly due to your review of the 2010 Expert with the brain, and some emails back and forth with you, and I like it a lot. In your review of the Rumblefish, which weighs in at 30 pounds, 10 ounces, the main over-riding complaint is that it feels heavy. But if I’m reading the scale correctly in the tiny pic posted in the other carbon vs aluminum article, the alloy Stumpy comes in at 30 pounds, 7 ounces.

I know the main point of the test was to compare the two frame materials, but there’s little to say how the alloy Stumpy rode, other than not quite as well as the carbon. But curious, did you feel this same heaviness to the ride with the Stumpy, or was the weight just not as notable as with the Rumblefiish? I’ve seen reviews of Specialized bikes in MBA, and they almost always mention how the bikes feel lighter than they actually turn out to weigh.

FatBob January 18, 2013 at 3:38 pm

Alfred, we cant decide which bike to buy for you. Our reviews cover quite a bit of detail. The StumpJumper is a favorite of us here at 29eronline. I have limited time on a Trance X 29 but we are testing one right now. Look for an introduction soon.

The Stumpjumper is an excellent descender. It climbs well but is no race bike. It strikes a very good balance of all around fun with a penchant for descending. The experience with the brain shock has been very positive for us here as well. I’m not sure I could say any bike was “better” then the StumpJumper as an all around trail bike. Again we just started our review process of the Giant so you’ll have to hang in there.

alfred January 13, 2013 at 11:52 pm

i want to somebody help me to decide witch bike is better the giant trance x29er 1 or the stumpy fsr carbon expert 29er i know that the stumpy have carbon frame but the truly answer that i made by my self is which suspension performs better i don’t want to feel tired uphill and i really want to fell confidence on the downhill zones giant maestro performance awesome but what about specialized fsr with brain it specialized better or giant its better help me please

Jon December 7, 2012 at 8:25 am

I think any 2×10 will will be better than my 3×9 Stumpy as far as low BB height goes. You get your BB too hight and you sacrifice handling capability.

FatBob November 22, 2012 at 4:39 pm

Hi Jay. Sorry to hear about you BB height woes. Yes we have ridden in a lot of rock gardens with this bike. We rarely hit our pedals anymore. It definitely took some time to get used too.

One thing you may want to do is to check your sag. The sweet spot for most of the crew is about 25% sag. I run it closer to 30% sag. If your sag is a bit to low you decrease BB height even more.

Jay November 11, 2012 at 7:58 pm

I hate how the bottom bracket is too low on this bike. My pedals are always scaping the rocks on technical trails. Anyone here ever charge this bike on rock gardens?

FatBob July 14, 2012 at 12:10 pm

As to the comments above. The 2 pound difference was bugging me. i stripped both bikes down and re weighed them. UPDATE There is only a 1 pound difference. Sorry for the confusion

DrDon July 11, 2012 at 5:53 pm

It seems that Pivot will not commit that its alum 5.7 is not as stiff as the carbon version. I think the difference in weight is less than a pound, which is pretty significant when factoring in total frame weight but to a clyde like myself — is it relevant? So, inherent design stiffness is of course important. Resistance to impact damage, ability to repair (carbon), mud clearance, etc., plus the aforementioned factors must be taken in to consideration.

FatBob July 11, 2012 at 10:15 am

Hi Louie. jumps to me are a non issue. you will have to adjust your timing a little. Also a slightly looser transition is a better take off for a 29er. The timing is different and will take time to learn it. Manuals, again, timing and finding the balance point. I am not great at manuals but I was no better on a 26er. Still the response of a 29er is a bit less snappy then a 26er. It is also harder to loop out in my opinion. As far as the front end being to heavy, its all about getting your weight back and learning how to work the larger wheel. The edge for ease and least effort to get into the air (not necessarily in the air)still goes to a 26er.

lars July 11, 2012 at 10:11 am

check. Nice review by the way

ps: I bought myself a Trek RF Pro this spring, very happy with it.

Have you had any chance to ride it yet?

FatBob July 11, 2012 at 9:47 am

Lars, while we are not scientifically measuring stiffness, for its intended use the bikes are stiff enough. I will agree that the Niner probably is a bit stiffer then the StumpJumper even by feel. Reality is though that when in the saddle both are stiff enough to ride hard and not have problems with absolute accurate control.

Yes the alloy model is not as stiff as the carbon. We felt better accuracy in steering precision with the carbon. We did have to ride the bikes back to back to notice and even then had to be pushing ourselves and the bike to notice. Nobody complained about he alloys stiffness. It is worth noting but flex does not disqualify the Alloy version. Additionally the parts do make a difference as when we put on stiffer wheels we noticed a great difference in performance. Note as well that stiffer components typically exaggerate the frames flex and is one reason we run a variety of wheels consistently on all the bikes we ride including $1000 frames so we can comment on the frames flex with complete confidence.

In short while the alloy frame does flex a little more then Carbon, neither StumpJumper has a problem with flex for our group of riders. Just don’t ask Sam Hill, pretty sure he would have problems no matter what he rode !

FatBob July 11, 2012 at 9:36 am

Andrew there is roughly a 2 pound difference. Between both comp models.

Grinder July 10, 2012 at 9:53 am

Great job 29eronline. I really appreciated getting the range of opinions from the different testers.

Another excellent review of the alloy FSR 29er EVO model concluded the frame was plenty stiff but flex in the components was a problem. An interesting perspective on the state of 29ers for all mountain riding on “the” north shore.


Andrew July 10, 2012 at 9:31 am

How much weight difference was there in the two bikes with the same build?

Tjaard July 10, 2012 at 5:42 am

Funny, in XC bikes it was reversed with Specialized and Trek.

The Epic Comp Carbon was 69.9 Nm/degr
The Superfly 100 carbon at 56.5 Nm/degr
Niner Jet 9 alloy 76.7 Nm/degr

larsv July 9, 2012 at 11:17 pm

regarding frame stiffness:
I just read a 29er all mountain group test in a german magazin.

One thing that strikes me: It claims that the FSR carbon frame is not stiff at all. In fact, it is the most flexible of the bunch. Three examples:

Niner Rip: 90Nm/deg
Trek Rumblefish 71 Nm/deg
Specialized FSR carbon expert: 60m/deg.

60Nm/deg is pretty low, it’s comparible to say, a Scott genius frame.

Could the aluminium frame be even more flexible?

Tjaard July 9, 2012 at 1:15 pm

I forgot to mention one of the good spec points is that the rims are 26mm wide instead of 24, so they mate well will tires over 2.0″ width.

Tjaard July 9, 2012 at 1:14 pm

I have a 2012 Comp Alloy and my rims came with tubeless tape installed, all I had to do was put in a valvestem.
I love my bike and would agree with the review. It’s a great all around trailbike that will take rough and steep trails but still pedal well and be fun to ride on smooth flowing trails. It does lack ‘snap’ compared to an Epic.

I ride mine with a 140mm Rockshox Revelation, which helps stiffen the front and slackens the head angle a bit, still no problem keeping it under control on slow climbs.

Tjaard July 9, 2012 at 1:10 pm

@ Louie:
The chainstays on the Stumpy 29 are over 15mm longer than on the current Trance X. this means it will take more effort to manual. The longer wheelbase and higher inertia of the wheels will make it less flickable as well. The Stumpies do have super low standover for a 29er.
This doesn’t mean it won’t jump well, but I would definitely guess less flickable.

rupert3k July 8, 2012 at 9:49 pm

Thanks to FatBob & all the riders who contributed to this excellent in depth article.

Louie July 8, 2012 at 6:47 am

Thanks for the in-depth review.

I’m still undecided about switching to a 29er. I currently have a giant trance. I love this bike cos I can flick it and do jumps on it. Will I be able to do jumps and manuals on the stump jumper FSR 29? I’m 5’9″ and not sure if this bike would be too front heavy for me.

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