Lighter Weight, More Travel - Trek Supercaliber Gen 2 First Ride 7

Increased travel, lighter SLR frame options and a new RockShox SIDLuxe IsoStrut make the new Trek Supercaliber Gen 2 a podium contender for any cross country racer.

Trek has been in the sub-100mm full-suspension XC bike category for several years, and in 2019, they released their first strut-designed Supercaliber featuring 60mm of rear travel and 100mm up front. Vital spent some time on the Gen 1 and praised its weight and sporty feel, but only 60mm of travel and steep (dare we say old) geometry left us wanting more. Enter 2023 and if imitation is actually flattering, the XC community confirmed as much on social media when Specialized released the 2023 Specialized Epic WC. Looking an awful lot like a Trek Supercaliber, the Instagram comments on the Specialized account giving Trek the nod were pretty entertaining. Specialized, however, wasn't using a strut design, but they had upped the ante with more travel (75mm rear) and slacker geometry; something we'd wanted in the original Supercaliber. Fast-forward five months and the new Gen 2 Supercaliber wins the travel battle (80mm rear), updates to modern XC geometry and slaps in a new, user-friendly RockShox SIDLuxe IsoStrut that is more serviceable than the FOX found on the Gen 1.


Big company drama aside, Vital had two test riders on the new Gen 2 Trek Supercaliber. Over the last few weeks, they've clocked some long local rides and even raced on the top-of-the-line, SLR 9.9 XX AXS model that we were sent. Our test bike is a World Cup XC-ready machine with a retail price of $11,699. Claimed weight for a size medium complete is 20.84 pounds. The base model Supercaliber Gen 2 starts at $4,199 and is a gallon of water heavier than our baller test bike. Trek offers 5 other XC weapons in the Supercaliber lineup, so let's get into what makes this Gen 2 Supercaliber different as well as our initial ride impressions.

Vital's Gen 1 Supercaliber test bike
Vital's Gen 1 Supercaliber test bike
Vital's Gen 2 Supercaliber test bike
Vital's Gen 2 Supercaliber test bike

Trek Supercaliber Gen 2 Highlights

  • Increased travel: From 60mm to 80mm rear, 100mm to 110mm front
  • Two levels of carbon frame: SLR and SL
  • Improved IsoStrut suspension
  • Updated geometry
  • Floating brake mount
  • S, M, ML, L, XL Sizes
  • Weight as tested: 22.6lbs / 10.25kg - Size L with 2.4 Bontrager Sainte RSL XR front tire, Shimano XTR pedals, 2 bottle cages
  • Prices from $4,199 to $11,699 (tested)

SLR SL or SL Models


  • 200-250 grams lighter than SL
  • No internal guide tubes
  • Mostly wireless spec.
  • Lightweight foam tubes included


  • Supercaliber 9.8, 9.9 SLR
  • Carbon 1-piece bar/stem
  • Carbon wheels


  • Weight comparable to Gen 1 Supercaliber
  • Same rear triangle as SLR
  • Includes internal guide tubes for easier cable routing


  • Supercaliber 9.6, 9.7 SL
  • Alloy cockpit
  • Alloy wheels

Engineering Notes:

There are no differences in frame shapes between SLR and SL. Carbon laminate and cable routing features in the front triangle are the difference as the SLR and SL share the same swingarm.

The primary difference in the material is fiber aerial weight (FAW), modulus, and amount of material. The SLR has lower FAW material, additional higher modulus material, and overall less material (i.e. fewer plies).

IsoStrut Design

Updated RockShox SIDLuxe ISOStrut
Updated RockShox SIDLuxe IsoStrut

Trek Supercaliber Gen 2 Models, Prices and Claimed Weights

$11,699 - Supercaliber SLR 9.9 XX AXS
$11,699 - Supercaliber SLR 9.9 XX AXS  - 20.84lbs / 9.45kg (size medium)
$9,549 - Supercaliber SLR 9.9 XTR
$9,549 - Supercaliber SLR 9.9 XTR - 21.5lbs / 9.75kg
$8,999 - Supercaliber SLR 9.9 X0 AXS
$8,999 - Supercaliber SLR 9.9 X0 AXS - 24.3lbs / 11kg
$7,349 - Supercaliber SLR 9.8 GX AXS
$7,349 - Supercaliber SLR 9.8 GX AXS - 24.9lbs / 11.28kg
$6,999 - Supercaliber SLR 9.8 XT
$6,999 - Supercaliber SLR 9.8 XT - 24.1lbs / 10.95kg
$5,699 - Supercaliber SL 9.7 AXS
$5,699 - Supercaliber SL 9.7 AXS - 26lbs / 11.8kg
$4,199 - Supercaliber SL 9.6
$4,199 - Supercaliber SL 9.6 - 28.9lbs / 13.1kg
$TBD - Supercaliber SLR Frameset - 4.3lbs / 1.95kg with IsoStrut
$TBD - Supercaliber SLR Frameset - 4.3lbs / 1.95kg with IsoStrut

Trek Supercaliber Gen 2 Key Spec Features

  • 9.9 SLR XX AXS - 20.84lb lightest build possible (size medium). Kovee RSL carbon wheels, XX SL AXS transmission, SID SL Ultimate fork, Fox Transfer SL dropper, Level Ultimate 4-piston brakes
  • 9.9 SLR XTR - Kovee RSL carbon wheels, XTR drivetrain, Fox Factory 34 SC fork, Fox Transfer SL dropper, XTR 2-piston brakes, RSL bar/stem
  • 9.9 SLR X0 AXS - Kovee Pro carbon wheels, XO AXS transmission, SID Ultimate fork, Reverb AXS dropper, Level Silver 4-piston brakes, RSL bar/stem
  • 9.8 SLR GX AXS - SLR Frame, Kovee Elite 30 carbon wheels, GX AXS transmission, SID 110mm fork, Line dropper, Level Bronze 4 piston brakes, RSL Bar/Stem
  • 9.8 SLR XT - SLR Frame, Kovee Elite 30 carbon wheels, XT drivetrain, Fox Perf. 34SC 110mm fork, Line dropper, XT 2 piston brakes, RSL Bar/Stem
  • 9.7 SL - SL Frame, Kovee Comp 25 Wheels, GX AXS transmission, Reba RL 110mm fork, Line dropper, SRAM Level Bronze 2 piston brakes
  • 9.6 SL - SL Frame, SLX/Deore drivetrain, Recon Gold RL 110mm fork, JD dropper, Shimano MT500 2 piston brakes

The Supercaliber uses a floating rear brake mount to isolate braking forces from the flex stays.




On the Trail and Race Course

Trek's focus on the Supercaliber is weight and going light may often mean trade-offs. Our test bike (SLR 9.9 XX AXS) is the only model in the new Supercaliber line with 2.2-inch Bontrager Sainte-Anne RSL XR tires front and rear. All the other models have 2.4 Sainte-Annes on both ends. Trek said this was to make the bike as light as possible. They also said that the SID SL Ultimate is technically only approved for tires up to 2.35 due to legal requirements around clearance. Many XC racers may not mind the stock 2.2-inch tires and SID SL Ultimate fork with 32mm stanchions as they chase seconds on the track, but it didn't take long for us to out-ride the waify configuration. For our riding style and terrain, the 2.2-inch front tire felt too sketchy, so we went outlaw and switched to a 2.4 Sainte-Anne (the same Bontrager model as our stock 2.2). We had no problems with clearance on the fork (it's literally 1.27mm wider than allowed), but perhaps muddy conditions could prove problematic. We left the stock 2.2-inch Sainte-Anne on the rear.

Chris Sanchirico rallying in Big Bear.
Chris Sanchirico rallying in Big Bear, CA.

The SID SL Ultimate fork felt a bit flimsy in rough conditions for our 175 lb testers. It has a 32mm chassis and weighs 1352 grams. The next bike down in the Supercaliber line, the SLR 9.9 X0 AXS, comes with a much stiffer SID Ultimate (35mm chassis, 1476 grams). Whether the weight savings is worth it will depend on your terrain and priorities.


The two-position fork and shock lockout on the SID and SIDLuxe IsoStrut worked well. Some riders may instinctively want a middle setting, but we found the two positions to be ideal. In the open setting, the pedaling efficiency was stellar without the bike feeling harsh like a hardtail. GripShift suspension lockout control was easy to use and left room for a full-size dropper lever. Compared to other XC bikes, the lockouts on the Supercaliber are barely necessary because of the bike's efficiency, but more of a "nice to have" for out-of-the-saddle sprints or long, smooth stretches.


By the numbers, the Supercaliber's 80mm of rear travel puts the bike in between a standard 100mm/110mm XC bike and a hardtail. In reality, this speedster is closer to being the best of both worlds - great pedaling efficiency combined with reasonable comfort and descending capability.

Carbon Bontrager RSL Integrated handlebar/stem, 0mm handlebar rise, -13 degree stem rise
Carbon Bontrager RSL Integrated handlebar/stem, 0mm handlebar rise, -13 degree stem rise

Riding position on the Supercalber is aggressive, but not uncomfortable and both of our testers (5'10" and 6') felt very comfortable on our size large. The one-piece Bontrager bar/stem combo geometry is locked in, save trimming width or adjusting stem height on the steer tube, so finicky riders with specific cockpit tastes should be advised. Head tube angle has slackened by 1.5 degrees, reach has grown 10mm across sizes and chainstay lengths have grown making for a stable, planted ride. While the seat tube angle steepens by half a degree, the standover height drops with a lower intersection between the seat tube and top tube.

Brad McDonald racing the Supercaliber in Big Bear.
Brad McDonald racing the Supercaliber in Big Bear, CA. Photo by Kristofer Stewart / Organic Bike Co.

Even with their quest for weight savings, thankfully Trek spec'd a dropper post on all models. Neither of our testers ride fixed seatposts. Our test bike was decked out with all the best SRAM and RockShox components but had a FOX Transfer SL instead of the RockShox Reverb AXS (found on the 9.9 SLR X0 AXS model) because of the weight difference.


What's the Bottom Line?

Both Vital testers, who regularly race XC and often take on longer endurance rides and events, said they would buy this World Cup-winning bike. If you're not a cross-country racer, in its stock trim, our Supercaliber SLR 9.9 XX AXS probably isn't for you with svelte 2.2-inch tires and a 32mm SID SL fork. Our Supercaliber 9.9 SLR test bike has shaved every gram and is bred for the race track, ready to tackle most XC race courses. For those wanting a little more diversity out of the bike, Trek offers Supercaliber models in both SLR and SL frame constructions with 2.4-inch tires and RockShox SID forks using 35mm stanchions. These weapons should handle any cross-country terrain and will even let you dabble in some legit backcountry epics.

Hit up to shop the new Supercaliber Gen 2.

View key specs, compare bikes, and rate the new Trek Supercaliber in the Vital MTB Product Guide.


Supercaliber Gen 2 FAQ Supplied by Trek


What is different about the frame compared to the previous generation of Supercaliber?

The frame is completely new to make it a more capable bike without sacrificing any of the speed. The travel has been increased from 60mm to 80mm rear travel and the front suspension has increased from 100mm to 110mm. The geometry has been updated with a slightly longer reach and slacker headtube angle. There are now two unique Supercaliber frames. There is a lightweight SL frame and a super lightweight SLR Supercaliber frame. The frames look identical, however, the SLR frame has a lighter carbon layup and does not have the internal cable routing guides on the mainframe. There is also a new RockShox SIDLuxe IsoStrut on all models.

What is the rear brake mount? What is the max rotor size?

160mm direct post mount. Minimum and maximum rear rotor is 160mm.

How much dropper post insertion does the frame have?

SM – 215mm MD – 225mm M/L – 250mm LG – 270mm XL – 330mm

What is the hub spacing?

The frame uses 148mm hub spacing and has a Universal Derailleur Hanger (UDH) for SRAM Eagle Transmission compatibility.

Which frame will be available as a frameset?

The lighter-weight SLR frame will be offered as a frameset.

What is the maximum fork axle-to-crown and/or travel?

The bike is designed for a 110mm travel fork, but it is compatible with 100 and 120mm forks. This allows the rider to choose the fork and travel that best suits their preference for geometry, weight, and performance. The maximum axle-to-race is 525mm.

Is there any downtube protection?

Yes. There is a clear 3M adhesive film placed on the underside of the downtube to protect the frame and paint from downtube strikes.

Is it compatible with SRAM T-Type transmissions?

Yes. It has a universal derailleur hanger that can be removed and a hangerless T-Type transmission used in its place.

What is the seat tube dimension?


Wheels & tires

What size tire is spec’d on the bikes?

All models get 29 x 2.4” tires except for the Supercaliber SLR 9.9 XX SL T-Type which has 29 x 2.2” tires on it to help save weight and because the new RockShox SID SL fork on that model has a max clearance for 29 x 2.35” tires.

Is it compatible with other wheel/tire sizes?

No. The bike is designed around fast-rolling 29” wheels on all sizes.

What is the maximum tire size?

Frame: 2.40" Fork: See manufacturer

Are these bikes tubeless compatible? What additional parts are required?

Yes. All models are tubeless out of the box. They include TLR strips, valves and sealant.

Can tubeless inserts be used with Supercaliber?

Yes, tire inserts can be installed if desired.


What type of bottom bracket does it use?

Like the previous generation, it uses a press-fit 92 bottom bracket.

Is it compatible with cranks with 30mm spindles?

Yes, but you'll need to supply your own 30mm bottom bracket and compatible crank.

What is the maximum chainring size? Minimum chainring size?

55mm chainline only. Min chainring is 30T, max chainring is 38T


Is the new frame compatible with the previous FOX IsoStrut?

No, the frame is only compatible with the new RockShox SIDLuxe IsoStrut due to several dimensional changes (eye-to-eye, stroke, diameter).

What is the recommended sag for the new RockShox IsoStrut?

New Supercaliber was designed around 25% IsoStrut sag for a balanced level of rider efficiency and suspension response. Riders can also adjust setup pressure throughout the 15-35% sag range, as marked on the new RockShox IsoStrut, to fine-tune their setup based on preference and riding conditions. Higher pressure/less sag = higher ride height and firmer and a more efficient pedaling bike, while lower pressure/more sag provides lower ride height and softer and more compliance through rough terrain.

Is there any special suspension setup knowledge needed for the RockShox IsoStrut?

There are sag gradients marked on the strut to help you easily set up and tune your preferred sag.

Also, the IsoStrut rebound has numeric labeling: 10 is slow rebound and 1 is fast rebound. Ya know, just like the podium, you're racing for. #1 is fastest and higher numbers are slower. (Hope that helps you remember.)

Are there IsoStrut air volume spacers?

Yes. However, installing the RockShox air volume spacers is different than FOX. A walk-thru is available on Trek U.


Can all sizes fit 2 water bottles?

Yes, all sizes can fit 2 water bottles – 1 on the seat tube and 1 on the downtube.

Are there any unique tools required for this frame?

There is a unique bushing tool needed for service. See the Supercaliber service manual for details.

What is the warranty?

Standard Trek warranty. Lifetime for the main frame of the original owner. More details here



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