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.