“Looks like a Session”. What started out as simply an observation quickly escalated through the ranks of funny joke to end up as a low hanging fruit of a comment that inadvertently actually got someone a free Scott Gambler. I’m still trying to wrap my head around that, and as such that will be the sole uttering of the phrase from me.
Back in 2019, the Trek development team asked some of their racers, fresh off the podium from the Snowshoe World Cup, to come and try something new out at the Mountain Creek Bike Park in New Jersey, US. Since that summer, Trek has been working away on the next iteration of the most winning DH bike of all time, and that racer feedback turned out to be critically important in defining what is now released - the 2022 Trek Session.
• Full 29", full 27.5" & mullet adaptable
• All aluminum construction
• 200 mm rear travel
• High pivot suspension system
• Adjustable geometry & suspension
• Sizes R1 - R3
• Bike Weight: 16.32kg to 16.87kg or 35.98lbs to 37.19lbs (claimed)
• Frame Weight: 4.12kg or 9.08lbs (claimed, w/o shock)
• Bike Pricing: €4,999 to €6,999 or $4,999 to $6,999 USD
• Frame Pricing: €2,999 or $2,999 USD
The new bike is another step forward for Trek with the Session line, with a bit more of a focus for them on refinement rather than starting from scratch. Yes, there are some very apparent changes that we’ll get into, but the lineage of the bike can still be clearly seen in the new version. And before you ask, no, I didn’t just say it.Frame Details
The two most immediately noticeable changes to the new Session are the suspension system and the frame material. We’ll go into the high pivot design in a minute, but first we can start with the material.
As with most frame prototypes in development, Trek did this with aluminum. Alongside this they were indeed working on the development of a carbon fibre composite frame. However, that development was halted after the overwhelmingly positive feedback about the aluminum prototype and its ride characteristics that Trek received from those early tests. It's something that Trek is actually full speed on trying to fully understand and quantify, by opening up the Pandora's box that is chassis stiffness. If a racer tells you that they are ready to take a prototype bike directly to race at the highest level, then you know you’re onto something.
The aluminum construction of the new bike was also accompanied by a conversation with Trek about aluminum perhaps being the right material choice for them for the demands of downhill. Trek’s racers also tested with added weights placed on the previous Session’s frame in different positions to understand its effects.
The second biggest change to the new Session is the switch to a high pivot suspension system. The origins of the change coming from a mix of looking at the competition in the world of DH race bikes while also looking internally. Some racers had also cottoned on to the competition’s success and also dropped the question about a high pivot design. Trek’s history already includes bikes with the same suspension ideas dating all the way back to 2003 with the Diesel and 2006 with the Session 10. Looking back to this, Trek asked what was good about those old high pivot bikes and if it was something that they would like to bring to the new Session.
How high does a pivot have to go before it’s a high pivot? According to Dylan Howes, Advanced Concepts Engineer at Trek and also the man behind every single Session there has ever been, once the pivot goes high enough that the use of an idler to change the chain line is needed, then it’s a high pivot design.
While the previous bike never had pinpoint problems coming from chain stretch, it was certainly one of the much-liked traits of the old high pivot bikes Trek had done before. By the same token, making sure the pivot wasn't too
high was also a driver in development. Once really up there, the axle path of the bike starts to become exclusively rearward, and this is something that Trek were wanting to avoid for the drastically changing chainstay geometry as the bike went through its travel.
More into the suspension side of things, Trek racers have often had custom links to adjust the suspension and that adjustment is something that is now offered to the public. Down at the lower shock mount is a small flip chip to adjust the bike’s leverage ratio progression between 20% and 25%.
The adjustability doesn’t end there, and with the inclusion of the Mino chips at the back of the rocker link the entire bike’s geometry can be adjusted. Out of the box the Session is a full 29” bike with the Mino link giving a High or Low setting.
There’s also the possibility to run a mullet wheel size setup by swapping the rear wheel out and running the Mino chip in High. The geometry is brought back to within a gnat’s whisker of the full 29” geometry. And with the addition of a longer bottom headset cup, it can even run a full 27.5” wheeled setup. Lots of rental stations use the Session and some are a bit apprehensive about making the switch to full on 29” DH bikes. It’s also good as lots of individuals still enjoy the full 27.5” wheel setup over a mullet or full 29”.
Cable routing is internal in the mainframe, entering at the forged head tube, travelling down the top tube and exiting just before the seat tube. There’s then a stretch of external routing down the back of the seat tube, which continues external for the brake along the chainstay and internal for the gear cable. There are also provisions on the underside of the top tube for external routing. Some people like the aesthetic of internal and others the functionality of external, so the two solutions can make everyone happy.
Accompanying the raise in the main pivot, the rocker link had to shrink to maintain the desired leverage ratios and progression. That meant that there was much less space for having a bridge connection from right to left sides of the link, as seen in a lot of Trek’s other bikes. So, they employed a system that locks the independent sides to the axle with pinch bolts.
There’s a 250mm eye to eye shock, which allowed Trek to use the bearing eyelet on the shock, connect the front of the link with one solid bolt and also make it a bit easier to work with for the customer.
There’s a pretty extensive bolt-on downtube protector that covers both the area’s most prone to rock strikes and damage from shuttling and certain chair lifts. Frame protection continues to the chainstay, with it now being in closer proximity to the chain and encountering it a lot more often. It uses a now almost industry wide style with raised softer sections dampening chain slap. It’s secured with a bolt up front and a zip tie at the rear.
Out back, the Session uses SRAM’s UDH derailleur hanger and a 157mm wide rear hub. On the full bikes the Bontrager hub actually does away with the spacer on the 7-speed cassette and widens the hub flanges both left and right to make use of the space in the wide hub.Geometry & Sizing
With the new Session, Trek shifts over to an R sizing model, with R1, R2 and R3 based around the reach numbers of the bike. Those three sizes have reach numbers of 440, 465 and 493 mm respectively. That’s a growth of between 25 and 32 mm per size compared to the previous carbon Session. With that growth, and there only being three sizes available, it does mean that the previous bike’s S size is kind of dropped.
As that reach, and front centre, lengthen, so too does the chainstay length. But Trek actually just shifted the bottom bracket position to achieve the change and, in the process, managed to keep the number of individual parts down to a minimum. Chainstay lengths are 439, 445 and 452mm.
There’s a 63° head angle in the low Mino chip setting and a 22.5 mm BB drop, giving an on-paper BB height of 350 mm.
The Session uses a 117 mm head tube length for all sizes, resulting in the same stack height across the board. That does increase though with the addition of the extended lower cup for the full 27.5” wheels setup.
Keeping the 29” wheels and moving to the high Mino chip position, the BB raises just under 9mm and the head angle steepens to 63.6°. The chainstays also get around 4 mm shorter and the reach grows by between 6-7 mm depending on the size. Travel has also increased slightly, to 204mm.
In the mullet setup, which needs the Mino chip in high, the geometry is very damn close to the full 29” bike in low Mino chip, with only one or two millimeters and a fraction of a degree making the difference.
All Sessions come with a 46mm offset fork and use a 72.5mm stroke shock.Suspension
The new Session uses the same single pivot system as the old bike, just with it all moved up a bit. The shock is driven by the linkage of the seatstay and rocker link.
With the two leverage ratio progression options the new Session can have 20% or 25% of progression. In the 20% option the bike is quite similar to the previous bike, albeit with a slightly higher starting ratio and a touch more travel. In the 25% option the starting ratio is raised to around 3.25 and gives slightly higher leverage ratios all the way through travel until it arrives at the same ending ratio. That would translate to needing a different spring rate to achieve the same shock sag or, say, if you were all setup in the 20% setting and moved directly to the 25% setting, then you’d have more sag. The inverse is true if you started in the 25% and moved to the 20%.
The high pivot design does indeed make the rear wheel move more rearward, 12mm to 25mm more on the new Session compared to the previous. But looking at the axle path it’s clear to see that Trek actively limited how high they went, with the new Session having almost equal parts rearward travel to forwards.
The inclusion of the idler pulley reduced the chain stretch of the bike as it goes through its travel and, as a result, one of its possible manifestations – pedal kickback. Depending on the gear ratio, the new bikes has 10° to 19° less pedal kickback than the previous bikes.
Trek maintain their ABP system, mounting the brake on the seatstay, and so on a system that rotates around an Instant Centre, or IC, dictated by the chainstay and link. This allowed them to actually reduce the anti-rise values quite considerably despite raising the main pivot of the bike. This very high anti-rise is often a trait of high pivot bikes and with the ABP system Trek reduced the values to around a third of what they would be if the brake was mounted on the chainstay.Options, Price & Availability
The new Session is available in two full bikes, Session 8 and Session 9, and a frameset. Prices are country specific so it’s best to check here
for the correct pricing in your country at the time of launch. Availability is from the 8th April, but that starts out not completely uniform throughout the world. It’s best to check in at your local Trek dealer for more detailed information for exactly where you are.Session 9
- RockShox Boxxer Ultimate fork and Super Deluxe Ultimate DH shock. SRAM X01 DH drivetrain. SRAM Code RSC brakes. Bontrager Line DH 30 wheels with Bontrager G5 Team Issue tyres. Bontrager carbon bars, stem, grips, seat post and saddle. 16.32kg or 35.98lbs (claimed). $6,999.99 USD, €6,999 (DE, FR, ES) or £6,300.Session 8
- RockShox Boxxer Select fork and Fox Van Performance shock. SRAM GX DH drivetrain with Truvativ Descendant DH cranks. SRAM Code R brakes. Bontrager Line DH 30 wheels with Bontrager G5 Team Issue tyres. Bontrager aluminum bars, stem, grips, seat post and saddle. 16.87 kg or 37.19lbs (claimed). $4,999.99 USD, €4,999 (DE, FR, ES) or £4,500.Session Frameset
- Fox DHX Performance shock, FSA Orbit headset. Available in Deep Deep Dark Blue to Alpine Blue fade. 5.22 kg or 11.5 lbs with shock (claimed). $2,999.99 USD, €2,999 (DE, FR, ES) or £2,750.Ride Impressions
As is the current normal of product launches, Trek sent out a Session prior to the launch, so I’ve been out riding the new Session all around my home trails of Switzerland for around four weeks now.
First things first, it’s a damn fast bike. And one that lets you know what’s going on quite nicely, allowing you to hit sections at ridiculous speeds and commitment levels only to get away with what you thought was pushing the risk just that tiny bit far. It’s been nothing but grin-inducing to get to know the Session so far, for precisely that character trait.
Initially, when we were organising the bike the sizes on offer did make me a little worried. At 188cm tall I saw myself falling in between the R2 and R3 sizes. But I knew that singling out the reach is only one aspect in bike fit and feel. So, I eventually decided on the R3 size and crossed my fingers that there was adjustability in the system and a similar philosophy in suspension feel to Trek's previous session. As it turned out, my luck was in.
The R3 size does feel big, but comfortably big. And then when you get the bike rolling and in amongst the roots and rocks it does actually ride shorter than that on paper number would suggest. I’ve only had the bike in the low Mino setting and full 29” guise for the moment. Moving to the high setting would increase the reach a touch, but it’s something that I will be testing out, along with the mullet setup, as more tracks and variety of terrain opens up as we roll into the summer season.
Suspension-wise I like to start out with 25% sag on a new bike. Although on the Session this felt a little too soft and made the bike wallow a touch more than I’d like, sapping some of the rider input into the bike that is much needed when a bike wants to go this damn fast. Upping the pressure, and so reducing the sag down to around 21%, has got the bike feeling nice and supportive both to the terrain and rider inputs while not really having the biggest of impacts to the suppleness of the system.
Out of the box I have needed to make a couple of changes, mainly swapping out the 180mm rear rotor and trimming the bars down from their initial 820mm width, but these are mostly preferences and something that every rider would need to do to make the bike their own.
Our R3 isn’t exactly a featherweight, at 17.2 kg or 37.93 lbs out of the box; there is a bit of heft there that is noticeable on the trail. While I’m not an advocate for lightweight being the number one priority, it still is an important factor in a bike. But there are a multitude of factors and it was nice to discuss these in detail with Trek and in relation to the Session. Its weight no doubt does have a role to play in the stability and steadfastness of the bike's character.
One character trait that I am having to figure out is when you grab the brakes; there doesn’t seem to be the feel of the tire knobs really getting in there and aiding the slowing down. Instead, the Session sometimes seems to skid across the top of the ground. I am still early on in the testing of the bike, and with so many tools for adjustment on the bike, I’m not overly worried that I can’t get to the cause of this feeling.
The 46mm offset Boxxer has been making turning a little tricky. Granted not so much up on the hill, but it’s a bit embarrassing to almost fall over at walking pace because you can’t turn your fork enough. And while most of the early season riding has been gloriously dry, there have been inevitable stints of wet and muddy riding. The cable routing at the back of the seat tube, along with the big chainstay bridge, has been acting like an anchor for the mud. I’ve also had to pay attention to the cables passing over the rocker link and keep them from rubbing away too much, which has already seen quite some wear from just four weeks of riding. An additional zip tie to pinch the cables has been working well so far.
All in all though, I’ve found myself at home incredibly quickly on the new Session and with the coming months I’m looking forward to not only riding it more in different terrain, but playing around with the adjustment options in the bike for the geometry, suspension and wheel sizes and seeing if its veracious addiction for speed continues throughout the entire test period.