$4,999 High-Pivot Trek Session 8 Review - Vital's Summer of Downhill 7

Setup, Fitment and Suspension Settings

As with all the downhill test bikes that will be a part of Vital’s Summer of Downhill shootout, we tested our Session 8 with the stock parts that come with the GX build. To match our test rider heights of 5-foot-10-inches and 6-foot, Trek provided a size R2 Session 8. The middle of the three sizes available, the R2 frame with dual 29-inch wheels in the low Mino Link configuration has a 465mm reach, 445mm chainstay length, and 1277mm wheelbase. When set up with a 29-inch front wheel, 27.5-inch rear wheel, and the high Mino Link configuration, the R2 frame has a 472mm reach, 441mm chainstay length, and 1274mm wheelbase. Stock cockpit components are handled entirely by Bontrager parts which includes the Bontrager Line 35mm bore aluminum handlebar which has a 27.5mm rise and 780mm width. The stem is a Bontrager Line Pro with a 35mm bore clamp and 50mm length. Finally, hand comfort is handled by Bontrager XR Trail Elite lock-on grips. On the Trek website there is a helpful Suspension Calculator that provides suspension settings based on rider weight. At the moment, the new Session is not included from the selection of bikes. With limited availability at this time, we would expect Trek to update their website when the new Session is more readily available. For setup purposes during our testing, we installed Sprindrex Springs to fine-tune spring weight for our two test riders. Both the RockShox Select fork and FOX VAN Performance rear shock we rode have only compression and rebound external adjustments. With a few fewer adjustments than the higher-end suspension we are fortunate to ride nowadays, we weren't left with knobs to adjust in hopes of making up for the lack of rider ability.

Sean’s Session 8 Setup

“This bike is gigantic,” was my internal dialog when first crawling on the size R2 Trek Session 8. The cockpit area felt like I had enough room to swim laps across the top tube and I knew some changes were necessary. Even though the 465mm reach was within my preferred sizing, the overall height of the front end put my weight too rearward over the bike. In an effort to feel more balanced and forward, I only ran a 10mm headset spacer under the fork crown and installed my own handlebar. The stock Bontrager Line handlebar was perfect at 780mm wide but just a tad too tall. I installed my go-to DEITY Racepoint handlebar with 25mm rise which helped lower the front end. Combined, these adjustments shifted my weight more forward and allowed me to dig into corners with more confidence. I felt I achieved a balanced fit on the Session 8, which left me more sat into the bike as opposed to riding on top of the bike. The Bontrager Line Pro direct mount stem worked fine for my needs as I prefer a 50mm length stem. However, the Bontrager XR Trail Elite grips were much too thin and after a few laps, my palms were beat up.

Suspension setup on the Session 8 was quite simple thanks to the limited adjustments on the base level fork and shock. I’m quite familiar with the Boxxer Select fork as it’s what I currently ride on my personal Specialized Demo. For setup, I simply carried over my existing settings from my Demo and applied them to the Session 8. My only gripe during setup was the lack of any volume spacers coming stock within the fork. I typically run 2-3 volume spacers and with none installed, noticed poor bottom out support on the final 50% of travel. Small bump sensitivity was spot-on. I chose to run rebound set neutral and compression mostly closed which provided a responsive and planted ride quality on trail. In the rear, I kept the Mino Link flip chip in the 25% progression setting for the duration of testing. After some initial fiddling with the Sprindex spring, I settled on a 440-pound spring weight. This was just under the stock 450-pound spring weight and allowed for a smoother bottom out and more active rear suspension around mid-stroke. For low-speed compression I ran enough damping to keep the shock supple, yet supported, during the initial part of travel and then relied on the progression of the high-pivot design to manage high-speed compression support.

Jason’s Session 8 Setup

Right off the bat I found the Session 8 R2 size fit me super well! When compared to the Pivot Phoenix 29 we tested first this summer, the reach is 5mm longer while chain stay length is only 3mm longer (29-inch rear wheel). Marginal differences yes, but I found myself located more comfortably centered on the Session 8 with plenty of room to maneuver the bike. The stock Bontrager Line handlebar has a rise of 27.5mm which lands just shy of my preferred 38mm (1.5-inches) bar height. To compensate, I added a 5mm spacer under the fork crown and lowered the fork stanchions 8mm in the crowns. Combined, these changes achieved a comfortably higher front end height. The stock bar width of 780mm was also under my preferred 787-790mm width, however, this wasn’t detrimental to my time on the Session 8. Trek does provide almost 30mm of headset spacers to adjust crown height which is convenient during initial setup. Down the road when a desired height is achieved I would likely cut the steerer tube nice and short for aesthetics. The Boxxer Select fork also came with a tall upper crown which provided even more height adjustment, especially when compared to a flat crown. I prefer a 50mm length stem so Bontrager’s Line Pro stem was perfect for keeping my weight balanced over the front wheel. There was also a 5mm stem riser mounted stock on our Session 8. Another nice touch to provide added adjustability when setting up your cockpit. I left the spacer mounted since I was generally raising the front end per my preferences and saw no need to lower the stem. Unfortunately similar to the Phoenix 29, the stock grips on the Session 8 had a harder compound and thin diameter. They were not great.

With a more rear-center riding position I typically find myself running my rear suspension a bit stiffer or with more compression damping than what is recommended. However, the progressive nature of the new Session’s high-pivot design actually left me over-sprung initially. The stock 450-pound spring on the FOX Van performance shock didn’t let me reach full travel and was too harsh on rougher trails. I played around with various spring weights since the Sprindex spring allows for 5-pound increment weight adjustments. Ultimately, I settled on a 430-pound spring weight. This let me reach full bottom out while keeping the rear end active in chattery sections and plenty supported for riding bike park trails. For external shock adjustments, I ran both rebound and compression one click open from neutral. I actually really enjoyed getting to ride base level suspension and was impressed with the performance of both the Boxxer Select fork and FOX VAN Performance rear shock. Despite the limited external adjustment, I felt a comfortable ride quality was achievable and it was nice to have a ‘set-it-and-forget-it” mentality. In the fork, I ran 125 psi with rebound one click open from neutral and low-speed compression one click closed from neutral. For reference, 125 psi is recommended for around 180-pound rider weight. My 168-pound weight should put me in the 118-120 psi range. The added pressure was necessary to keep the fork supported given the limited compression adjustments and lack of volume spacers coming stock in the fork. If I were to spend more time aboard the Session, the addition of 2-3 volume spacers would provide a more supported, progressive feel and allow me to drop pressure down to the recommended amount for my rider weight.

The Session's High-Pivot Design Is Bred For Pure Downhill Racing

Trails Ridden 

All testing on our Session 8 was split between The Basin Gravity Park and Tamarack Ski Resort. Both bike parks are close to our home base of Boise, Idaho, and offer a variety of trails between them. The Basin is mostly machine-built trails with countless flowing berms and jumps featuring an average higher speed. There is a great, short, rocky downhill trail called G19 that is prime for smashing. In contrast, Tamarack is mostly raw, single track with limited built-up features. It offers some properly rough, technical, and rocky descents. Summer weather brings dry, dusty mountain soil so trail conditions were dry, dusty and loose with most test days reaching 90-degrees Fahrenheit.

Sean's Impressions 

What a machine! The new Trek Session 8 rides like a purebred race bike built to maintain traction, handle heavy impacts and accelerate through the roughest bits of trail. My favorite characteristic of the new high-pivot design was the minimal trail feedback felt through my feet and ankles. With the idler pulley basically eliminating pedal kickback, my feet remained unfazed through chunky rock gardens or heavy compressions. Trek’s ABP design really enables the rear suspension to remain fully active under braking forces, resulting in a very settled and composed feel. The rearward axle path did wonders for maintaining and generating forward momentum despite harsh compressions. At times the speed carried through rough sections due to the suspension design actually required an altered approach to my braking points. On multiple occasions I found myself trail-braking (feathering the rear brake) in loose rock gardens to stabilize the Session 8. Cornering took time to perfect as the growth in overall wheelbase when compressing into a turn is a unique feeling. A phenomenon which occurs that any high-pivot design, I did struggle to get my weight over the front wheel as desired. The Bontrager G5 front tire also did not provide any help when fighting for traction. Watch the video to see me hit the ground like a sack of potatoes for proof!  

Is the Session 8 my top choice for my next bike park slayer? No, however I’m no Kade Edwards. The nature of the high-pivot design puts the Session 8 into the racehorse category for me. On flowy, jump riddled trails the performance could be described as the antonym of playful. Stability is plentiful but the Session 8 was reluctant to cut shapes into the dirt at my command. Sizing down to a medium frame and running a 27.5-inch rear wheel would likely increase the fun factor. But for me, the Session 8 is best suited on pure downhill tracks. If ridden in a race setting, I would choose the R2 size with mixed wheel configuration to best blend maneuverability and stability at speed.

Jason's Impressions 

I actually have a short history with Trek’s Session downhill bike having raced one in 2012 and 2015. In 2012 I raced for the Trek/ODI Satellite Team which was managed by Rich Houseman and Aaron Gwin. I was teammates with standouts Charlie Harrison and Shane Leslie who both have had successful racing careers and are back aboard Trek bikes in 2021. At that time I was 17-years old and my 26-inch, aluminum Session 8 was the sickest bike I had ridden to date. Of course my knowledge of what separates bikes from one another was limited back then but I vividly remember riding with a new level of confidence on the Session. In 2015 I purchased a pre-production aluminum 27.5-inch test mule Session from a Trek test team. With a few years of racing experience at that point, the most memorable aspect of that Session was how predictable and adaptable its four bar linkage felt. It was a joy to toss around down flow trails and never held me back when between the tape. It’s actually the only downhill bike I’ve kept over the years as it was hand welded in Wisconsin.

Needless to say, I was excited to try out the new Session design and see how it compared to the platform I’d ridden in the past. The most immediate difference and standout characteristic of the 2021 Session is how stable and composed it remains in rough, repetitive compressions. The high-pivot design truly reigns supreme when sections of trail should overpower the abilities of the bike. On countless occasions, I braced for impact entering chunky rock gardens but would exit almost unfazed with minimal forces transferred through to my body. The Session 8 has an impressive ability to remain level and composed no matter how square a compression you encounter. This characteristic was incredibly confidence-inspiring and kept my riding position centered despite variations in trail pitch or features. The ability of the rear wheel to essentially get out of the way and absorb impacts helped maintain forward momentum with no sensation of being hung up. At speed, the Session 8 never danced or twitched under me from small bump chatter. Again, with a rearward axle path comes wheelbase growth as you progress through travel which benefits overall stability. It’s been talked about plenty in the past, but Trek’s ABP design successfully kept the suspension active and engaged with the ground under braking. Another factor benefiting control and stability, we noticed this most on steep trails where braking points and traction were crucial.

Hands down, the Session 8 takes the top spot when it comes to managing rough, raw sections of trail. With that said, it is not my first choice to rack up frequent flyer miles. The previous Session was evenly split between bike park ripper and downhill race steed. The new Session now leans heavily towards maximizing composure at speed and leaves a bit to be desired when riding flow trails. Some riders will likely enjoy this stability when tackling new, bigger jump lines with added confidence. However, for those looking to pop off trailside jibs or get sideways on every jump, big or small, it’s going to take some real effort to make the Session 8 cooperate.

I rode our Session 8 with dual 29-inch wheels and mixed 29-inch front, 27.5-inch rear wheel configuration. With the smaller 27.5-inch rear wheel installed, I did notice improved maneuverability while cornering. In tight turns or back-to-back berms, I could whip the Session 8 around on a tighter turning radius than with a 29-inch rear wheel. This improved the fun factor when riding flow trails, being able to wind up the bike and slap corners recklessly. At speed or in technical sections of trail, I never noticed any lack of stability or increased rear wheel hang up. If anything, the smaller wheel gave the sensation of sitting deeper in the bike which helped me drop my heels for an improved riding position. What’s the bottom line on the mixed wheel option? If I was taking the Session 8 racing I would show up with dual 29-inch wheels every time. But for a weekend of ripping party laps with friends, I would toss on the 27.5-inch rear wheel to keep things quick and fun.

Rear Suspension Performance

Sean's Impressions

The rearward axle path of the Session's new high-pivot design manages rough compressions with exceptional finesse. It almost defies physics when you topple over a harsh bump and feel like you have sped up from the impact. Even though the platform is fairly progressive I never experienced any harsh bottom outs or limitations achieving full travel. We left our Session 8 in the 25% progression rate setting during testing as I never felt the need to lean towards more of a plush setup. However, I love the fact that Trek provides riders this extra level of adjustability if a smoother ride profile is desired. As mentioned above, I experienced absolutely no pedal kickback due to the idler pulley but did notice some lost pedaling efficiency. The idler functioned flawlessly and created a silent ride, however adding an extra moving bearing undeniably increases drag. When combined with the higher weight of the Session 8 it did take a few additional stomps on the pedals to get up to speed. The FOX VAN Performance shock worked surprisingly well and impressed me with its flawless execution and tuning simplicity. The lack of numerous external clickers made me realize low-speed compression and rebound are plenty sufficient for the majority of riders. Myself included. Unless you are competing at a high level, the addition of multiple shaft rate adjustments can create setup confusion and excuses. If I was looking to upgrade my stock rear suspension I would start with a Sprindex Spring prior to purchasing an aftermarket shock. The cost is significantly less and the additional adjustability is both useful and easy to manage.

Jason's Impressions

The previous Sessions I rode always felt fairly linear and would have benefited from some added bottom-out resistance. To my satisfaction, from my initial run, it was pretty obvious improvements to ending-stroke support had been made on the new Session. All my test time was spent in the 25% progression Mino Link flip chip setting and I never felt the need to lessen the progression rate. Being on the lighter side, I often rely on pumping the smallest trail features to maintain speed. The mid-to-end stroke support offered with the 25% progression setting comfortably pushed back against my efforts and allowed for speed to be gained from pumping. I was also pleased with how supple the initial stroke remained on the new Session platform in part to the ABP design. A personal favorite characteristic carried over from the previous Session, there was superb traction and small bump compliance. When hitting large compressions, I did not feel the progressive design kept full travel from being achieved or created a harsh ride experience. As mentioned with my initial setup, settling on the correct 430-pound spring weight was key for performance. Big surprise, right? At this spring weight, I could yank to flat off of jumps and trust the shock would reach a comfortable bottom out. And at the same time, this spring weight remained light enough to keep the bike active around mid-stroke where the majority of ride time was spent.

Session 8 29 ‘GX’ Build Kit

Sean's Standout Components: SRAM GX Drivetrain, TruVativ Descendant Cranks, Bontrager Line DH 30 Wheels 

My favorite part of the Session 8 build kit was the SRAM GX drivetrain. The GX groupset delivers the same crisp SRAM shifting engagement as XO1 and worked flawlessly for the duration of our testing. I would have a hard time finding a reason to bump up to XO1 components given the performance of GX nowadays. The clutch of the rear derailleur did a phenomenal job limiting excess chain slap and kept the Session 8 rolling quieter than the Shimano Zee derailleur on our Pivot Phoenix 29. The next standout part spec was the TruVativ Descendant DH aluminum cranks. Not that carbon isn’t up to the job of downhill riding, I enjoyed the added peace of mind riding with durable aluminum cranks and enjoyed their stiff compliance. My last standout component on the Session 8 GX build was the Bontrager Line DH 30 wheelset. They took a beating during testing and the rims have absolutely no dents, hops or wobbles to be seen. I also loved the Rapid Drive rear hub which has 108 points of engagement. Our other downhill test bikes have either low-level or unbranded hubs with minimal points of engagement. The crisp buzz of the Rapid Drive hub rolling down the trail was a pleasant addition that made it feel like I was riding an aftermarket wheelset.

Sean's Least-favorite Components: Bontrager G5 Team Issue Front Tire

My biggest peeve with the Session 8 was Bontrager’s G5 Team Issue tire when used as a front tire. The channel present between the center and side knobs created an unpredictable feel when cornering on loose over hardpack conditions. I had the tendency to begin pushing the front wheel before the side knobs would engage with the ground and would have to put out a foot to counter the front tire slide. As a rear tire, the tight center knobs rolled great and I found the channel between the center and side knobs wasn’t an issue.

Jason's Standout Components: Boxxer Select Fork, FOX VAN Performance Shock 

Despite the limited external adjustments, both the Boxxer Select fork and FOX Van Performance shock performed well above my expectations. Sure, if I was going to tackle elite level downhill racing again I would make the jump to more expensive and tunable suspension. But for my daily downhill bike, the base level suspension did not hold me back on the trail. The Boxxer’s Charger RC damper is highly refined and provides great initial bump compliance with comfortable mid-to-end stroke support. The Select model uses the same chassis as the top-tier Boxxer Ultimate which offers great torsional stiffness. Lastly, the Maxima damper fluid basically eliminates any seal or stanchion stickiness. My experience with the FOX VAN performance shock was similar. The shock did not hold back the capabilities of the Session 8. Even on quick, harsh compressions I never felt like the shock was being overpowered and the mid-stroke support was a highlight of mine.

Jason's Least-favorite Components: Code RS Brakes, 180mm Rear Rotor

My biggest complaint with the Session 8 was the 180mm rear rotor. With most downhill riders running 200-220mm rotors I’d expect Trek to at least spec the Session 8 with 200mm rotors front and rear. I don’t think I’m alone when I admit I use more rear brake than front during a day of downhill laps. The smaller, 180mm rear rotor managed heat poorly and caused our Session 8 test bike to burn through the rear pads at a much faster rate than the front pads. This resulted in a large difference in lever throw between our front and rear Rode R brakes. This was problematic since Code R brakes lack a pad contact adjustment. To compensate, I was forced to move the rear lever further out from the bar to maintain a consistent bite point.

Noise

What noise? The Session 8 is undoubtedly the quietest bike in our Summer of Downhill test fleet. Some of our test bikes were obviously specced with low-end derailleurs in an effort to save cost. Not the case with the Session 8. The SRAM GX DH 7-speed drivetrain not only functioned flawlessly but was impressively silent with almost no chain slap to be heard. Aiding in deadening any drivetrain rattle was the idler pulley and ribbed chain slap frame protection. There were no areas of noise concern on the rest of our Session 8. The internally routed cables fit snug into the frame ports and with a few extra points of rear hub engagement, there was no freehub knock or play. A standout aspect of the new Session platform, we don’t expect our Session 8 to start talking back anytime soon.

Value

Coming in at $4,999 USD the Session 8 29 GX build provides riders with a race-ready package. All the components are appropriate and ready to take on countless days of shredding right out of the box. There is also the added value of having multiple frame adjustments and the option to run different wheel sizes, making the Session 8 multiple bikes in one. When discussed between our two testers, they felt committing to the two thousand dollar price jump for the highest tier, Session 9 XO1 build at $6,999 USD wasn’t worth the bacon. The difference is an upgrade to higher-end SRAM X01 drivetrain, SRAM Code RSC brakes, RockShox Boxxer Ultimate fork, and Super Deluxe Ultimate air rear shock. Looking into the future for our own test Session 8, the only immediate changes we would make would be bolting on a 200mm rear rotor and installing higher-end brakes with pad contact adjust. All remaining components function wonderfully and we would opt to upgrade other components as typical wear and tear intervals present themselves. Another big factor adding value to the Session 8 is Trek’s extensive dealer network. The ability to have assistance with maintenance and troubleshooting problems is a huge benefit to shopping with a box brand like Trek. While some consumer-direct brands do offer similar builds with a lower price tag, riders will have to weigh if they feel comfortable taking on maintenance without dealer-level support.

What's The Bottom Line?

Trek had no reason to redesign their Session downhill bike after years of proven success. But when racing at the highest level, the search for saved time never halts. Luckily for downhill riders worldwide, the new platform only elevates the already successful Session pedigree. The high-pivot suspension layout in conjunction with Trek’s ABP design provides the best of both worlds with supple, small bump compliance, and controlled bottom-out resistance. The rearward axle path scoffs at square edge hits and allows the Session 8 to carry better speed than most bikes out there. With geometry and progression adjustments, size-specific chainstays, dual 29-inch, 27.5-inch and mixed wheel options possible - the Session is multiple bikes packaged into one. To top things off, the Session 8 build offers riders a complete build that is both lighter on their wallet and laced with quality, race-ready components. While the past Session design was synonymous with trail-bike-esque weight possibilities, the Session 8 tips the scales and doesn’t try to hide its full aluminum frame. Boosting jumps and slapping berms aren’t going to come easy as the Session 8 was developed to maximize speed in a straight line. But with the right setup, we believe most riders will be able to swing a leg over the Session 8 and enjoy multiple seasons of downhill laps.

For more information on Trek’s Session lineup, head over to www.trekbikes.com

To view key specs and compare bikes, head over to the Vital MTB Product Guide