As one of the bikes everyone’s been buzzing about, Trek finally took the official wraps off of the already World Cup winning Session 9.9 carbon at Trek World Mayrhofen. As Trek’s master of suspension, Jose Gonzales was happy to point out, the Session 9.9 is the compilation of just about every current mountain bike buzz word with the addition of technologies first showcased on the 9.9. While you may want to dismiss the 9.9 as just a carbon Session, it is actually a new bike from the ground up with a design that also carries into the aluminum sessions as well.

The new Session is leaner, stronger, a lot lighter (nearly 2 pounds in just the frame!), and most of all, an all out race rocket. Even though the 9.9 will no doubt be out of most everyone’s budget, it showcases just what can be done and knowing trek will be a vehicle of trickle down tech for other bikes in the future.

Jump past the break for more on how Trek ensured the Carbon Session was up to the task!

All photos credit Sterling Lorence/Trek


Yes, you are seeing that correctly. With only a hand full of carbon 9.9 Sessions that currently exist in the world, Trek already has one cut up to show the magic beneath the surface. One of the goals of the 9.9 project wasn’t just to make a carbon DH bike, but to make a carbon DH bike that was not only lighter than its aluminum counterparts, but stronger as well. As you can imagine, a DH bike has to stand up to a lot more abuse and different forces than your average XC bike, so building the ultimate carbon DH rig wasn’t as simple as just building it in the black stuff.


Trek eventually settled on a new carbon strengthening technique that they coined InTension, which is utilized on the for the main frame and seatstays on the 9.9. InTension is specifically used to distribute the load between two flanges in high stress and high bending areas such as pivots, bottom brackets, and seat tubes. The low density, ultra stiff material boasts 4 times the flexural strength of a similar carbon-only structure, and is 8 times stiffer. In the photo above, the InTension material is shown by the blue patches in the seat tube. In addition to the seat tube, InTension is also used throughout the junction between the bottom bracket shell and the main pivot point to make sure everything is as stiff and straight as possible, even when pinning it at race speed.


The other new technology Trek is introducing with the Session 9.9, is a yet another collaboration with Fox Racing Shox to produce the first Fox 40 with an air preload, dubbed Hybrid Air. The Hybrid Air system adds the convenience of simply using a shock pump to dial in your DH fork. With one spring weight and the Hybrid Air system, Fox and Trek have been able to create a fork that has the same range of tune-ability with one spring, as a standard Fox 40 with the whole spring range. Most importantly, it will retain the plush ride feel of the coil, as Trek wanted to make absolutely sure the air spring didn’t have an effect on overall feel. To top it all of, with the included titanium spring, the Hybrid Air fork is still 60g lighter than other 40’s. Currently, the Hybrid Air system is only available on the 9.9 carbon Session, adding to its impressive list of features.


Adding to the 9.9’s suspension prowess, all carbon Sessions will be equipped with the World Cup level DHX RC4 rear shock. With externally adjustable high and low speed velocity sensitive rebound and compression damping, if you can’t get the shock tuned to your liking, you’re probably doing it wrong. Not only is the RC4 itself a great shock, but the 9.9 comes with the very same custom tune that you will find on Gwin or Moseley’s WC winning bikes. The Aluminum Session 88 also gets an identical tune, only in the RC2 rear shock, which is essentially the same minus a few external adjustments. The Fox DHX RC4 is bolted to the front of a new HEX MC Carbon Evo link which serves to stiffen the frame even further, but also plays a role in the Session’s new geometry.


When it comes to the Session’s geometry, there is a lot going on, as in 28 different combinations of settings between the Mino Link, Angleset, and fork settings. To start with, Trek improved the leverage ratio of the suspension which allowed the Session to bump up to 210mm  of total rear wheel travel. With the Mino link, you are offered two settings: Race and Park. The feel of the bike in the two settings is fairly self explanatory, in Race mode the bike is lower, longer, and tracks better over square edged hits and offers great stability in the steeps. In park mode the rear suspension offers more pop off of lips, and a more agile overall feel. Due to the fact that both the Session 9.9 and the Session 88 come stock with a Cane Creek Angleset, you have even more adjustment, up to 1.5 degrees either way, of the head angle of your bike.

But wait, there’s more! Like most of Trek’s 2012 MTB offerings, the Session 9.9 has a few cable routing tricks up its sleeve. For starters, if you want you can use the Sessions Internal control routing which is cleverly integrated into the replaceable fork bumpers on the head tube. Also, again like a lot of Trek’s longer travel MTBs this year, the Session 9.9 is Reverb Stealth compatible.


Or, if you want to keep all of your cable routing external, the Session 9.9 has you covered there as well. Instead of opting for standard cable guides, Trek created a guide method called MicroTruss which is supposedly lighter than standard guides, and increases the strength of the frame as well.


Last but not least, the Session’s new 157×12 ABP DH rear end. Now, now, before you get too excited about a new standard, consider the facts. 157×12 is following in 142×12’s foot steps, in that in order to make installing the wheel easier, slots have been made in the frame for the axle to rest. In order to keep everything else the same, a total of 7mm had to be added to the axle so that the cassette would clear the chainstays. Just like Trek’s ABP convert, the Session’s system includes the hardware to run a standard 15omm wide rear hub. Not only can you take advantage of 157’s easier wheel changes, but if you buy the frame only, or have other wheels already you can still use them. Also like 142×12, I wouldn’t be surprised if 157×12 started catching on in the near future.

Perhaps the best news for the average rider, is that most of the design changes to the Session 9.9 have been passed down to the Aluminum Sessions as well. If you don’t have the coin for the top of the line 9.9 (price ytbd), you can still get a lot of World cup level downhill bike tech, at a more affordable price.


  1. 157×12……?

    lets just make all BB’s, front and rear axels and pivots the same size and bearings. lets just say…..200mm. that should eliminate all flex and be strong enough for xc to dh racing. then manufactures and us riders won’t keep having to have parts with all different sorts of sizes that will not interchange.

  2. I love the way the chain guide is mounted in the first picture.
    I bet the bike is awesome but that is so much bad publicity, they don’t even know how to assemble the guide correctly.

What do you think?