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2021 Trek Supercaliber 9.8 GX Bike

Vital Rating: (Excellent)
2021 Trek Supercaliber 9.8 GX (Gloss Radioactive Red/Matte Black)
2021 Trek Supercaliber 9.8 GX Bike 2021 Trek Supercaliber 9.8 GX Bike 2021 Trek Supercaliber 9.8 GX Bike 2021 Trek Supercaliber 9.8 GX Bike 2021 Trek Supercaliber 9.8 GX Bike 2021 Trek Supercaliber 9.8 GX Bike 2021 Trek Supercaliber 9.8 GX Bike 2021 Trek Supercaliber 9.8 GX Bike
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XC Speed Demon: Trek Supercaliber Review

If you are looking to squeeze every bit of speed out of the trail with a little more comfort than a hardtail, Trek's new race weapon could be for you.

Rating: Vital Review
XC Speed Demon: Trek Supercaliber Review

In 2019, Trek showed up to the World Cup with a mysterious XC bike that was under wraps for most of the racing season, with what was sure to be a unique suspension layout and some fancy tech hiding under the hood. Eventually, after every cycling forum overflowed with bad photoshopped images of the new bike, the real deal was unleashed unto the market. The frame designers had taken a different approach to making a fast race bike, and in parallel with a new Top Fuel being released with revised geometry and more travel, Trek opened a space in their line-up for a “not a hard-tail and not a full-suss bike” - meet the SuperCaliber.



  • Agile, sporty feel
  • Stiff frame, great power transfer
  • Open shock mode is more dynamic and efficient than other bikes in this category
  • Lively geometry, very good cornering ability
  • Good brakes and wheels
  • Unique looks
  • Simple frame layout with only two bearings
  • 60 is not 100
  • Short reach and steep head angle are not so confidence-inspiring
  • Proprietary rear shock
  • Unique looks
  • Heavy frame for the price and amount of travel

Trek Supercaliber 9.8 GX 2021 Highlights

  • Full carbon frame with integrated shock
  • 29-inch wheels for all sizes
  • Full SRAM GX groupset
  • Shimano XT brakes
  • Carbon wheels, handlebar and seatpost
  • 100/60 mm F/R suspension travel
  • Sizes : S, M, M/L, L, XL, XXL
  • Weight: 11.15 kg, size L including 2 bottle cages, Garmin mount, XTR pedals and a Quarq power meter (as tested)
  • MSRP: $6299.99 USD

Initial Impressions

Excited to test the new bike after seeing it tear up the race tracks, we took delivery of the 2021 9.8 model. Highlighting the spec are the updated GX Eagle groupset from SRAM, Shimano XT brakes and Kovee Pro 30 wheels from Bontrager.


The innovative frame makes use of one single pivot above the bottom bracket and a 36 mm stanchion under the top tube that the seat stays are attached to. This stanchion is not actually the shock itself, just a sliding mechanism that allows the suspension to move. Inside is a fully functional rear shock, with compression and rebound damping, as well as lockout on all build levels. The bike is even supplied with air volume spacers for more tunability. Instead of using pivots on the chain stays or seat stays, the seat stays flex during suspension compression, a very common sight in this category of bikes. Moving the shock out of the way like this creates a frame with hardtail-like lines and lots of room for water bottle storage.


The frame is well put together, with lightweight protection added in critical areas like under the bottom bracket. The Supercaliber uses Trek's "Straight Shot" frame design principles, which means that because of the straight shape of the downtube, the fork crown could come into contact with the frame if it were to rotate all the way around. A “knock block” headset prevents this from happening, but there is also an additional bumper on the downtube itself as an extra safeguard (a good idea, as we’ve already seen knock block headsets rotate in the stem thus circumventing the knock block in a crash). The cable routing is fully internal and will support pretty much any combination of cables that you might need to run, including the remote lockout for the shock.


Looking over the geometry charts, we find none of those “long low slack” numbers that would point to any “downcountry” aspirations here. The head angle is steep, the head tube is short and the reach is conservative at best - but this is a cross country race weapon and not a trail bike. The Supercaliber was built to pedal and not to help you feel like a hero on the descents. We tested a size L and except for running a longer stem, the numbers worked well for our 1m83 tester.


We started testing the bike during a recovery week in our program, mainly to help the body to adapt to the new seating position. In the first couple of rides the bike developed some creaks and other noises from the headset and rear suspension. The area around the shock serves as an oil bath to keep the sliding mechanism lubricated - it consists of two bushings and wipers just like you’ll find in a suspension fork. It was running a bit dry which was the cause of the noise, once we got everything lubricated properly the bike was quiet again.


On The Trail

The best way to describe the first sensation you get from this bike is “agility”. No frills speed and very reactive handling, like you’d get from an old school, manual transmission sports car, think Lotus Elise. Everything about this bike is sporty and athletic. The handling, the ultra short travel, the power delivery to the ground and so on. Our testing started out in conditions that would have been best described as “rough”. If we could use two words, we’d say “rough as”, and to make it a whole sentence - “the trails haven't seen a drop of water in 6 months and are broken to pieces”. As testing went on, rainy season moved in and we were able to put the bike through a fair bit of riding in wet conditions as well.


Although XC is becoming more and more technical, the races are still won on the climbs and this is where the Supercaliber really shines. The rear end is well controlled, even with the suspension fully open, and the sturdy chain stays will help squeeze the most out of any power put to the pedals and turn it into forward movement. Traction and grip while climbing was very good, and we did not feel the need to use any lockout during 95% of the riding and testing we did. The lockout lever controls both the shock and the fork at the same time, and it did work well whenever we did actually use it. We initially worried that the knock block headset would get in the way in really tight turns, but that concern soon proved to be unfounded.


That sporty initial impression did not fade away during testing and indeed we always felt that need for speed on the Supercaliber. Smooth ground is where this bike really stands out with its very responsive behavior. Want to rip those gravel roads to the trail head? Want to take that KOM on your local flowy loop? Want to kick your mates’ butts on that technical climb to the top? The Supercaliber is all-in. The relatively short frame, a short stem and a steep, 69-degree head angle all contribute to this quickness. We did end up replacing the stock 80mm stem on our size L with a 90mm in order to open a bit more space in the seated position and to calm the steering a bit (we also ran the bike with a lightweight, 60mm dropper post from DT Swiss for the majority of the testing period - more on that component will follow in a separate review).


So far so good, and the Supercaliber managed to go at least as fast as its rivals as long as the going was smooth. When things got rough, is where the Supercaliber reached its limits quicker than other modern 100mm bikes we’ve ridden. Hitting drops or certain jumps will be accompanied by a clear bottom out from the rear shock and maybe a tire rub on the stays here and there. In this regard, the flex stays are both an advantage and disadvantage. On the one hand, they add some complementary compliance to the rear end of the bike, something that is welcome when all you have is 60 mm of rear travel. On the other end, that flexy rear end felt like a limiting factor on some hard descents. To be clear, some of the heavier sections we pointed the Supercaliber down during testing will not appear at any race track you will face, but if they do, this bike will not be the brightest star on the start line.


To sum up our riding impressions, we’re intrigued by the Supercaliber concept. If you’re used to racing hardtails and you’re looking for something to take the sting out of the trails, the Supercaliber feels like the right tool for the job. You really don’t miss out on much of that hardtail directness, while the extra compliance and grip offered by the 60 millimeters of flex stay travel are a clear bonus on technical climbs. Just don’t go expecting the Supercaliber to have any kind of “downcountry” aspirations, as the short and steep geo numbers and the inherent limitations of the rear suspension were not meant to add any extra confidence on the descents. We think of the Supercaliber as a very specific tool that will add a degree of comfort and grip for strong, technical riders who will be able to exploit the highly reactive aspects of the handling to their advantage. To really test out the racing readiness of the Supercaliber, our tester Yonatan lined up at the start of the Israeli National XC Marathon Championships just recently, where he took the win in the "Pro" category (7th place overall in "Elite"), despite not having specifically trained for it.


Component Highlights

FOX FLOAT DPS Performance for Trek IsoStrut rear shock: The SuperCaliber's rear suspension was developed in collaboration with FOX Racing Shox so it came as no surprise to see a fork from the same manufacturer. The rear shock is of FOX's "Performance” level and features rebound adjustment and a 2-position lockout as well as the ability to change the air volume with additional spacers that are supplied with the bike. The rear shock itself performed flawlessly during the testing period with no change in compression behavior or air pressure. It seems like the durability that we have often enjoyed with FOX rear shocks was not left behind in the design process here.


FOX FLOAT 32 Step-Cast (SC) Performance fork: The bike's fork did work as well as the shock, although we were perhaps expecting to see a "Performance Elite" spec on this level of build as well. The Performance level gets a slightly heavier chassis, in addition to forgoing the Kashima coating on the stanchions. The GRIP 2-position damper has a remote lockout that is activated together with the lockout of the shock, as well as externally adjustable rebound. As stated in the riding impressions, the lockout works well but we did find the bike efficient enough to not have to use it 95% of the time. As for the durability, the fork didn’t suffer any unusual performance degradation, and after a full winter of riding will only need lower leg service to work as new again.

Shimano XT M8100 brakes with Ice-Tech rotors: These brakes are just solid, they’re not flashy, and with that dark grey finish they look like they mean business too. No carbon or titanium to be seen here hence they’re not superlight. Stopping power is very good and so is the modulation. The new lever design feels way more solid on the bar compared to the previous version and the two bar contact points that now sit further from the grip help open up space for the extra levers present on this bike.


SRAM GX Eagle 12-speed Groupset with 10-52 Cassette: For the 2021 model, SRAM stepped up with the revised GX Eagle version that was released earlier in 2020. We were expecting a little more from the Supercaliber at this price point, unfortunately, the chain has worn out in less than 1000 kilometers and the cassette is showing considerable wear to the black coating in the smaller 6 cogs. This tester was also not a fan of that last cog growing to 52t all alone without the next cog or two also being adjusted, the jump is too big and creates a dead space in climbing cadence and speed. We would love to have the cassette arranged differently:

Current: 52-42-36-32-28-24-21-18-16-14-12-10
Suggested: 52-45-38-32-

Other than that, the system is for sure an improvement in overall performance compared to the previous version with better precision in gear changes.


Bontrager Kovee Pro 30 Wheelset: For 2021, Trek decided to bump up the spec of the 9.8 model to the Pro level wheels (compared to the Elite level on the 2020 model). The Pro wheels are 215 grams lighter, have double the engagement points in the rear hub and DT swiss bladed spokes for better compliance and overall performance. This upgrade is a blessing and really fits with the intended use of the bike.


Bontrager XR2 2.2 Tires: At first, this tire was not what we thought of as the most suitable choice for this bike, as Bontrager’s XR1 rolls faster. After several months of use however, with almost no issues with the tires, we feel like the XR2 is a nice spec option for this bike. The tread is not slow by any means and is suitable for a variety of surfaces and will likely fit any rider's need for speed, grip and puncture protection.

Things That Could Be Improved

The rear suspension was squeaking when we started testing the bike. It was not the actual shock but the seals on the sliding stanchion. The two seals are paired with two foam blocks, much the same as the foam rings in your fork. These foam blocks were totally dry as well as the seals themselves. We knew how to deal with that quite easily but it is always a shame for the customer to buy a squeaky bike and then having to come back to the shop to fix it.

The 2021 9.8 model received some spec upgrades compared to the 2020 version, in the form of better wheels and brakes. We’d like to see the drivetrain get that treatment as well.

Long-Term Durability

After a long testing period, lots of miles, lots of trails and lots of rainy days riding the SuperCaliber, it was time to hit the workshop and see how the bike has held up. The finish of the frame’s color remains as new after a good wash, leaving the bike looking like it just left the shop. As we mentioned, the frame uses only two bearings in the suspension, and so far, we have not detected any problems from the BB area where they sit in the frame - we might end up replacing them now just for good measure, but it's not really required at this point. The wheels are spinning straight and very true. We've replaced the bearings of the hubs, but that was after a properly wet winter of riding that would challenge any hubs that we know. All other components have shown an usual amount of wear except for the chain which has worn out faster than expected.


What’s The Bottom Line?

Trek released what is essentially a new breed of XC mountain bike with the introduction of the Supercaliber. A sporty and very dedicated machine, specifically made for racing applications, the Supercaliber is a demanding beast. As such, it will reward a skillful racer whose intentions are on the same page as the bike’s - go fast with no merci. Other than a few small setbacks with creaks and noises at the start of the test, our test bike has worked flawlessly ever since those issues were addressed, and it continues to deliver a fast and furious riding experience whenever we’re looking for it. Trek also offers the Supercaliber through their ProjectOne custom paint program, so you can fully customize the bike to match your local club’s kit or your racing team without needing factory level support. Look good, feel good - race good!

More information at

Vital MTB Rating

  • Climbing: 5 stars
  • Descending: 3.5 stars
  • Fun Factor: 3 stars
  • Value: 4 stars
  • Overall Impression: 4 stars

About The Reviewer

Yonatan Yatom - Age: 26 // Years Riding MTB: 15 // Height :6'0" (1.83m) // Weight: 161 pounds (73kg)

Yonatan is a born racer and a bike addict. As a true competitor the only thing on his mind when lining up in the start gate is the finish line. With a background in local enduro and DH races and even the occasional appearance in an Enduro World Series on his resume, Yonatan has more recently applied himself to building bigger legs and trying his luck racing XC as well. Throughout the week he’ll be manning the spanners at the bike shop, reading about new stuff on the internet, and thinking about how to improve everything he rides. Yonatan’s riding style is fully pinned, smooth, and quiet but can be nasty to his bike when needed.

Photos by Johan Hjord


Product Trek Supercaliber 9.8 GX Bike
Model Year 2021
Riding Type Cross Country
Rider Unisex
Sizes and Geometry
SM, MD, ML, LG, XL, XXL View Geometry
Top Tube Length 565mm 595mm 610mm 625mm 659mm 683mm
Head Tube Angle 69° 69° 69° 69° 69° 69°
Head Tube Length 90mm 90mm 90mm 90mm 105mm 120mm
Seat Tube Angle 74° 74° 74° 74° 74° 74°
Seat Tube Length 394mm 419mm 445mm 470mm 508mm 546mm
Bottom Bracket Height 320mm (53mm drop) 320mm (53mm drop) 320mm (53mm drop) 320mm (53mm drop) 320mm (53mm drop) 320mm (53mm drop)
Chainstay Length 430mm 430mm 430mm 430mm 430mm 430mm
Wheelbase 1079mm 1106mm 1121mm 1136mm 1172mm 1197mm
Standover 750mm 760mm 760mm 787mm 787mm 787mm
Reach 395mm 452mm 440mm 455mm 485mm 505mm
Stack 594mm 594mm 594mm 594mm 608mm 622mm
Wheel Size 29"
Frame Material Carbon Fiber
Frame Material Details OCLV Mountain Carbon front and rear triangles, molded chainstay protection
Rear Travel 60mm
Rear Shock FOX FLOAT DPS Performance for Trek IsoStrut, 2-position damper, remote lockout, 235mm x 32.5mm
Fork FOX FLOAT 32 Step-Cast (SC) Performance, EVOL, GRIP 2-positon damper, remote lockout, 44mm offset
Fork Travel 100mm
Head Tube Diameter Tapered, 1.125" top, 1.5" bottom
Headset Trek Knock Block Integrated, 62° radius, cartridge bearing
Handlebar Bontrager Kovee Pro, OCLV Carbon, 35mm clamp diameter, 5mm rise, 720mm width
Stem Bontrager Kovee Pro, 35mm bar clamp, Knock Block and Blendr compatible, 13° drop
Length: 60mm (SM), 70mm (MD/ML), 80mm (LG/XL), 90mm (XXL)
Grips ESI Chunky silicone, slip-on
Brakes Shimano Deore XT M8100, 2-piston, Shimano RT76 6-bolt rotors (180mm front, 160mm rear)
Brake Levers Shimano Deore XT M8100
Drivetrain 1x
Shifters SRAM GX Eagle, 12-speed
Front Derailleur None
Rear Derailleur SRAM GX Eagle, 12-speed
ISCG Tabs No
Chainguide None
Cranks SRAM GX Eagle Carbon DUB, 170mm length (SM), 175mm length (MD/ML/LG/XL/XXL)
Chainrings SRAM GX Eagle, 32 tooth, alloy
Bottom Bracket SRAM DUB, 92mm PressFit
Pedals None
Chain SRAM GX Eagle, 12-speed
Cassette SRAM GX Eagle XG-1275, 12-speed, 10-52 tooth
Rims Bontrager Kovee Pro 30, carbon, tubeless ready
Hubs Bontrager Kovee Pro 30 wheelset, 6-bolt rotor mounts, 110x15mm Boost front, 148x12mm Boost rear with Rapid Drive 108 tooth freehub and XD driver
Spokes Bontrager Kovee Pro 30 wheelset
Tires Bontrager XR2 Team Issue, tubeless ready, Inner Strength sidewall, aramid bead, 120 TPI, 29" x 2.2"
Saddle Bontrager Montrose Elite, titanium rails, 138mm width
Seatpost Bontrager Pro, OCLV Carbon, zero offset, 330mm length (SM), 400mm length (MD/ML/LG/XL/XXL)
Seatpost Diameter 31.6mm
Seatpost Clamp Single bolt, 36.4mm
Rear Dropout / Hub Dimensions 148x12mm Boost
Max. Tire Size 2.2"
Bottle Cage Mounts Two inside front triangle
Colors Matte Raw Carbon/Gloss Trek Black, Carbon Blue Smoke/Radioactive Coral, Gloss Radioactive Red/Matte Black
Warranty Lifetime frame and wheels; 2 years Trek/Bontrager parts, suspension linkage components, and paint/decals
Weight 22 lb 14.1 oz (10,380 g)
Miscellaneous IsoStrut integrated suspension design with pivotless seatstays
Straight Shot frame design with Knock Block steerer stop
Control Freak internal cable routing (including internal dropper post routing)
Includes Bontrager TLR tubeless rim strips, valves, and sealant
Weight given for size MD with tubes
  • $6,299.99
  • $6,799.99
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