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Trek Mountain Bike Buyer’s Guide - Best Trek Mountain Bikes (Supercaliber, Procaliber & more)

Whether you have World Cup XC aspirations or dream of epic downhills, Trek has a mountain bike for you. Here's the skinny on Supercaliber, Fuel, Fuel EX, Slash, and many other models.

Written by: Bruce Lin

Published on:

Posted in:Guides

Trek’s wide range of mountain bikes covers everything from ultra-lightweight XC hardtails to downhill and enduro trail slashers. But how do you know which Trek mountain bike is right for you?

This overview is your guide to all things Trek MTB. In addition to covering every model in the current Trek mountain bike catalog, we’ll decode Trek naming conventions and delve into Trek’s innovations in rear-shock technology.

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Trek XC bikes

Trek Procaliber

Trek Procaliber

Wheel Size: 29”
Suspension travel: 100mm front

The Procaliber is Trek’s carbon XC hardtail and its lightest mountain bike. It’s a pure cross-country race bike optimized for fast courses where maximum pedaling efficiency is essential for climbing and acceleration. It features a rear IsoSpeed decoupler that provides extra compliance over rough roots and rocks.

Who it’s for: XC riders who want the lightest, most efficient bike, or who ride less-technical terrain.

Trek X-Caliber

Trek Xcaliber

Wheel Size: 29” (27.5” for S)
Suspension travel: 100mm front

The X-Caliber is Trek’s entry-level, aluminum XC hardtail. The lightweight aluminum frame provides lots of performance on fast courses without breaking the bank. It’s a great option for newer riders looking to get into XC racing.

Who it’s for: XC riders and racers looking for a budget hardtail.

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Trek Supercaliber

Trek Supercaliber

Wheel Size: 29”
Suspension travel: 100mm front / 60mm rear

The Supercaliber is Trek’s lightest, most efficient, full-suspension XC bike. During development, Trek kept the Supercaliber under wraps (they literally hid the rear suspension during races) while Trek’s factory race team tested it at World Cups. The Supercaliber uses a unique IsoStrut suspension system with a frame-integrated shock. This provides 60mm of suspension travel, just enough to take the edge off bumps and harsh impacts while keeping the weight, stiffness, and efficiency close to the Procaliber hardtail. The Supercaliber is designed to be the perfect compromise between a hardtail and a 100mm full-suspension bike.

Who it’s for: XC riders looking for the lightest, most efficient full-suspension race bike available.

Trek Top Fuel

Trek Top Fuel

Wheel Size: 29”
Suspension travel: 120mm front / 115mm rear

The Top Fuel is Trek’s full-suspension marathon XC bike. The previous generation Top Fuel was a pure XC race bike with 100mm of travel front and rear. In 2020, the travel was been increased to make it more capable on descents. The Top Fuel could be considered Trek’s “downcountry” bike, a cross-country bike that balances downhill performance and pedaling efficiency. It will hold its own in fast XC races, but it’s versatile enough for trail riders who enjoy big rides on technical terrain.

Who it’s for: Marathon XC racers and riders looking for a “downcountry” bike.

Trek trail bikes

Getting sendy on a Trek trail bike
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Trek Fuel EX

Trek Fuel EX

Wheel Size: 29” (27.5” available for XS and S)
Suspension travel: 140mm front / 130mm rear

The Fuel EX is Trek’s most popular mountain bike model, and for good reason. The latest generation of this all-rounder has been refined with more suspension travel and modern geometry to make it equally capable uphill and downhill. It’s designed to suit the majority of riders and the widest range of terrain. If you’re looking for a quiver killer bike that will feel comfortable, capable, and efficient enough for all types of riding, the Fuel EX is a top choice.

Who it’s for: Trail riders looking for one bike to handle everything from XC to technical downhill trails.

Trek Roscoe

Trek Roscoe

Wheel Size: 27.5” plus
Suspension travel: 120mm front (100mm on XS)

The Roscoe is Trek’s basic aluminum trail hardtail with 27.5” plus tires for traction and comfort. The robust aluminum frame and affordable component builds make it a great choice for newer riders building their confidence and skills on the trail.

Who it’s for: Trail riders looking for a fun, inexpensive, easy to maintain hardtail trail bike.

Trek Stache and Full Stache

Trek Full Stache

Wheel Size: 29” plus
Suspension travel: 120mm front / 130mm front and rear

Discontinued in 2021, the Stache and Full Stache were Trek’s 29-plus hardtail and full-suspension models, respectively. These extra-large wheels and tires enhance rollover, traction, and comfort. These models are loved by bikepackers who need to carry large amounts of gear and desire extra comfort for backcountry riding and multi-day journeys.

Who it’s for: Trail riders and bikepackers looking for a mountain bike that maximizes traction and comfort.

Trek Farley

Trek Farley

Wheel Size: 27.5” Fat
Suspension travel: 100mm front or Rigid

The Farley is Trek’s fat bike specializing in terrain like snow and sand which require the additional “float” and traction of 4-5” wide fat tires. The newest generation of Farley uses 27.5” diameter fat tires instead of traditional 26” fat tires. Trek is a believer that using a larger diameter tire offers better performance in all conditions.

Who it’s for: Riders riding snow and sand.

Trek enduro bikes

Schralping it on a Trek enduro bike
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Trek Remedy

Trek Remedy

Wheel Size: 27.5”
Suspension travel: 160mm front / 150mm rear

The Remedy is Trek’s playful 27.5” trail bike. Older Remedy models were available with 29” wheels, but with the latest generation, Trek has committed to making the Remedy its sole 27.5” full-suspension bike. An ample amount of suspension travel allows the Remedy to tackle tough and steep downhill terrain while smaller 27.5” wheels make it feel easier to maneuver and throw around. It will suit riders who jump and jib their way down trails and who prioritize style and fun over all-out speed.

Who it’s for: Trail riders looking for a capable and playful bike.

Trek Slash

Trek Slash

Wheel Size: 29”
Suspension travel: 170mm front / 160mm rear

The Slash is Trek’s 29er enduro race bike. It provides the most suspension travel and slackest geometry short of Trek’s Session downhill bike. Available only with 29” wheels, it smooths out the gnarliest terrain and maximizes downhill speed. The Slash is used by Trek’s factory Enduro World Series race team and will suit riders looking for a competitive enduro race bike, or a bike that will enhance their confidence on steep and technical downhill trails.

Who it’s for: Enduro racers and riders looking for the most downhill capable bike that can still be pedaled uphill.

Trek MTB range

Trek has a huge selection of mountain bike models, and within every model, there is a wide range of builds to choose from. The hierarchy within models is described using letters and numbers that can be confusing to uninitiated buyers. Below is a guide to decoding Trek’s naming and numbering system.


Trek mountain bike range

Trek mountain bike models use a number (e.g. Trek Fuel EX 9.9) to indicate the frame material and component build. Models with a 5 through 8 use aluminum frames, with 5 indicating entry-level builds and 8 indicating top-of-the-line aluminum builds.

Models with a 9 use carbon frames. To differentiate build levels within carbon models, Trek uses a decimal system that ranges from 9.5 to 9.9, with 9.5 indicating entry-level builds and 9.9 indicating top-of-the-line builds.

Higher numbered bikes cost more but are equipped with better components.

For example, a Fuel EX 9.9 ($9,499) has a top-of-the-line OCLV carbon frame, SRAM XX1 Eagle AXS drivetrain, Fox Factory suspension, and carbon wheels, stem, and handlebars. A Fuel EX 5 ($2,399) has a more budget-friendly aluminum frame, Shimano Deore drivetrain, entry-level RockShox and X-Fusion suspension, and alloy wheels, stem, and handlebars. In between are several Fuel EX models that offer different frame materials and component builds so riders can pick the bike that fits their needs and budget.

Trek suspension technology

Trek has a long history of innovation, and it has introduced several ground-breaking technologies to the sport. Here is a list of technology and features that are only found on Trek mountain bikes.

Trek RE:aktiv and Thru Shaft shocks

Reactive shock

In 2014, Trek worked with Penske Racing to develop RE:aktiv valve technology for its rear shocks. In RE:aktiv shocks, a spring-loaded valve inside the shock body provides increased low-speed compression for more pedaling support. When the shock's shaft speed increases on rough terrain, the valve opens up to quickly absorb impacts before closing again. RE:aktiv shocks are designed to reduce the need for lockouts and compression adjustment on full-suspension mountain bikes when pedaling on smooth terrain or climbing.

In 2018, Trek added Thru Shaft to its RE:aktiv shocks. Most mountain bike shocks are designed around an internal floating piston, or IFP. When a shock absorbs a bump, a damper shaft moves through the shock and displaces oil. This displaced oil needs to go somewhere, so it pushes against the IFP, compressing a gas charge behind the IFP.

The Thru Shaft design eliminates the need for an IFP by allowing the damper shaft to exit out the bottom of the shock. The damper no longer needs to compress an IFP to create space for displaced oil. This makes the shock more responsive and reduces friction. RE:aktiv Thru Shaft shocks are currently found on the Fuel EX, Remedy, and Slash.

Trek IsoStrut

Trek Isostrut

IsoStrut is a minimal, frame-integrated shock designed to provide the comfort and control of rear suspension while maintaining weight, stiffness, and efficiency that rivals a hardtail. To save weight, instead of an ABP suspension pivot, there is flex built into the seat stays to provide a virtual pivot. In its current form, it is only found on the Supercaliber cross-country bike where it provides 60mm of suspension travel.

Trek Knock Block and Straight Shot down tubes

Knock Block detail

Most mountain bike frames have a curve in the down tube where it joins the head tube to prevent interference with the fork crown. Trek’s Straight Shot down tubes, however, are straight from the head tube to the bottom bracket to increase frame stiffness and strength. This means the fork crown might hit the down tube if it spins around during a crash.

The Knock Block system prevents this with a chip in the top tube that interacts with a keyed stem, spacers, and headset top cover. The Knock Block stops the handlebars and fork from spinning, preventing the fork crown from striking the down tube. There's also a molded guard on the down tube as a redundant measure. As an added bonus, Knock Block also prevents brake and shift levers from scratching or damaging the top tube.

Knock Block can be found on all of Trek’s carbon mountain bike models and the aluminum versions of the Fuel EX, Remedy, and Slash.

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Hopefully this guide to Trek mountain bikes puts you in a better place to select the best Trek MTB to suit you riding needs (and also the best build for your price range). If you’re still having trouble deciding, reach out to a TPC Ride Guide at (866) 401-9636 who can better help you understand the pros and cons, and ultimately find the right bike for you. Do you already have one of these Treks? Let us (and other cyclists) know in the comments what you love about your Trek MTB.

What do you ride? Which Trek bike is your favorite? What questions do you have? Let us know in the comments!