Comparing Fat Bike Build Weights

DURABILITY vs. WEIGHT vs. PRICE


When building a Fat Bike, there are three main considerations : DURABILITY, PRICE, and WEIGHT.

Our goal at RideFATbikes.ca, is to always build the strongest and lightest fat bike for any given budget. As such, Durability and Weight take priority in our bike builds over Price. Someone will always be able to beat our prices, but they will seldom be able to offer a stronger and lighter fat bike, for any given price point.

  • Yes, ASTM CAT ratings are probably the most important part of any successful bike design, and should not be ignored by the builder, or the customer.

    • A bicycle’s ASTM CAT strength and durability ratings range from 1 (weakest) to 5 (strongest), and are assigned to all successfully tested frameset, wheelset and components of a bicycle. A bicycle’s intended use is directly related to the ASTM CAT ratings of its installed components.

    • Details can be found at www.astm.org, or searching on the ASTM Classifications of Bicycle Usage document titled “ASTM F2043-13”.

  • We build all of our 4-season adventure Fat bikes to ASTM CAT 3/4/5 ratings.

    Whereas, some manufacturers build their Fat bike framesets to pass only ASTM CAT 2 test ratings, and then focus selling their frames and component kits at that level (ASTM CAT2), which can significantly reduce the price of their bikes. We do not regularly stock the lower-tier ASTM CAT2 framesets or components, as they tend to fail outside of sand and snow environments.

    RideFATbikes.ca goes a few steps further, so our bikes are rated durable enough to ride/race on more technical and challenging trails and terrain, in any weather condition, or season of the year. This translates to LESS WARRANTY CLAIMS overall (most times, no warranty claims for the lifespan of the frame, components and wheelsets).

    The goal = EVERYONE saves time from not having to deal with a broken down bike, while you watch the snow fall outside and miss riding in the winter season, or that vacation trip you were planning, or seasonal race that you were training for.

    RideFATbikes.ca builds our custom 4-season Fat bikes with proven quality parts that have experienced the least amount of warranty issues, and are at least Trail / All-Mountain rated (ASTM CAT 3+).

    AKA = we do not cut any corners, or introduce compromises in our custom builds.

    Each custom bike is built to your budget, using the best available components for that price point.

    • The weight of a completely built bike, minus the pedals, tubeless sealant, bottle cages, Garmin/phone mounts. This is the weight that manufacturers will specify on their website bicycle descriptions for each make/model/version they offer.

    • The final weight of the bike, built and ready to ride or compete in a race.

    • (for fat bikes, this includes pedals and sealant, which are items not included in MFG build kit specifications)

    • Note: A pair of good Alloy platform pedals average about 450 gr (1 lb) a set, and 16oz of tubeless sealant (for large 26x4.8” or 27.5x4.5” tires) averages about 1 lb, using 8oz in each tire.


Industry-Standard “ASTM CAT” Durability Ratings

  • ASTM CAT 1

    • rated for road bicycle use only

  • ASTM CAT 2

    • rated components and frames for road, gravel, sand and snow use only (majority of “big box retailer” carbon fat bike frames and carbon wheelsets fall into this category). This is the bare minimum acceptable rating for fat bike frames.

    • Designed for winter use, or beach riding.

    • Not designed for technical and aggressive singletrack riding

    • Not rated for jumping

    • Drops of 15cm (6” or less)

    • light-duty rolling XC is the limit of the frame/fork’s design capability

    • Some bikes in this category are NOT rated for suspension use. Installation of a suspension fork may void the warranty. Even worse, some frames in this category are not suspension-corrected, meaning that if you do try to install a suspension fork, it may hit the downtube when turning side-to-side, or, the geometry may be significantly affected (for the worse) by the addition of a suspension fork with a much taller AC height (Axle-to-crown height) than the “stock” rigid fork that came with the bike at time of initial purchase. Always ask the retailer if the Fat bike you are looking to buy has a suspension-corrected frame. If it does not, you can be assured the frame was designed pre-2015ish, and will not have the most ideal (comfortable) geometry or frame construction techniques. (Usually another red flag is a 2 year or less frame and fork warranty on ASTM CAT2 frames).

    • Fat bike frames in this category may have weight restrictions of 230 lbs or less -> combined rider+gear+frame weight.

    • (Close inspection of frame warranty may list a host of “conditional use” warnings that completely VOID the warranty, and elude to “catastrophic failure” and “serious injury or death” if bike is ridden “outside its intended usage”, including but not limited to operation in extreme temperatures, rider+gear weight limits, suspension use, trail use, competition use, etc, etc.)

      • AKA = this is not a serious 4-season fat bike frame/component/wheelset design if you like to ride hard and be competitive amongst your fellow riders. If your goal is a high-performing fat bike, you shouldn’t get drawn into these lower-priced designs and their “Crash Replacement” programs, if you can’t even ride this bike 4-seasons and in technical singletrack without worrying about a frame or “branded” component or wheelset failure, causing an extended warranty downtime waiting on replacement parts as the winter season rolls on by.

    • Here is an example of a “CAT2” fat bike frame/component warranty : link : < Borealis Bikes > (all Borealis branded parts are declared in their warranty as ASTM CAT2, including the frame, fork, carbon rims, seatpost and handlebars.)

  • ASTM CAT 3

    • Trail MTB rated, all-season, all-weather conditions.

    (this is where the fun begins!)

    • Jumps and drops are intended to be less than 61cm (24”).

    • rated for 4-season use, in any weather condition.

    • rated for suspension use (usually 60-120mm, dependent on the frame geometry and suspension fork selected -> frame size can play a big factor here!)

    • ASTM CAT 3, is the standard by which we start all our Fat bike builds.

    • here is an example of a “CAT3” fat bike frameset warranty : link : < 9:ZERO:7 bikes > (short and right to the point. This bike is built for high-performance, competition use, singletrack use, all 4-seasons of the year, no weather or temperature restrictions, no rider+gear restrictions, and it’s a winning design in the most grueling Fat bike races on the planet like the ITI Alaska).

    • Carbon framesets in this category like the OTSO VOYTEK and 9:ZERO:7 LYNX, may cost a bit more, but they are designed to withstand the abuse and perform at the highest levels expected for a hardtail fat bike.

  • Item description

  • ASTM CAT 5

    • DH-rated gear. This includes the FOES MUTZ full-suspension Fat bike w / Mastodon PRO suspension fork, many Atomik Carbon wheelsets, and all of the Derby DH carbon wheelsets used on our long-travel suspension fat bikes. Top-level gear, the best of the best.

    • extreme jumping; or downhill grades on rough trails at speeds in excess of 40 km/h (25 mph); or a combination thereof.


RideFATbikes.ca Custom Build Weights

9:ZERO:7 LYNX v2 (carbon / hardtail) = 22+ lbs

OTSO VOYTEK v2 (carbon / hardtail) = 22+ lbs

9:ZERO:7 TUNDRA (alloy / hardtail) = 24+ lbs

FOES MUTZ v3 (alloy / full-sus) = 32+ lbs


RideFATbikes.ca Custom Fat Bike Build Kits

  • SRAM GX Eagle (wireless or mechanical 12spd shifting) builds

    • 25-26 lbs on average

    • Carbon frame and fork

    • (alloy wheelset, crank, seatpost, w/ carbon handlebar)

    • < Click here > for an example “STAGE 1 GX” RideFATbikes.ca build spec

  • SRAM XO1 Eagle (mechanical 12spd shifting) builds

    • 23.5-25.5 lbs on average

    • Carbon frame and fork

    • (carbon wheelset, crank, handlebar and seatpost)

  • SRAM AXS XO/XX Eagle (wireless 12spd) custom builds

    • 22-24 lbs on average

    • Carbon frame and fork

    • (Top-tier Carbon, Titanium and aerospace polymer components.

    • < Click here > for an example “STAGE 3 AXS XO” RideFATbikes.ca build spec

    • The absolute best possible components, designed for extreme performance.

    • This type of build usually is done for either of two reasons :

      • extreme top-tier winter XC Fat Bike racing

        • ie: Fat Bike World Championships (Colorado) or Fat Bike Birkie (Wisconsin) on OTSO Voytek or 9:Zero:7 Lynx

      • ASTM CAT4 (Fat Bike) technical trail and downhill racing, where jumps above ASTM CAT3 parameters are likely to occur.

        • ie : Whiteface Mountain, Lake Placid NY (Foes Mutz v3 w/150mm travel)

    • Dropping down to ASTM CAT2 durability may be necessary on some parts (like the wheelset) to achieve the 21 lb weight goal of winter racing (such as very lightweight carbon wheelsets designed only for snow racing use). we always use Fat Bike frames that are rated ASTM CAT3+ (because we found the ASTM CAT2 frames developed warranty issues or failed with frequency).

    • STAGE 4 Extreme builds are condition specific custom built bikes, to achieve a specific performance or weight goal (usually cannot achieve both without sacrificing Durability)

Now check out the offerings from some of the more popular Fat Bike brands:

ASTM CAT 3 RATED FAT BIKES

  • the best model from each manufacturer was selected for fair comparison

  • links to MFG verified weights provided

  • you will see our custom Otso Voytek and 9:Zero:7 Lynx build kits save 3-9 lbs over the bikes listed below

    (updated for 2025)

2025 Salsa Beargrease XO1 EAGLE

  • ASTM CAT3 rated

  • new frame design in 2019+ (uses classic geometry)

  • Same model release in 2025 as in 2022

  • Carbon frame and fork

  • 5 Frame sizes

  • Carbon wheelset, handlebar, seatpost and crank

  • SRAM GX / XO1 drivetrain mix

  • SRAM G2 RSC brakeset w/160mm rotors

  • 27.5 x 3.8” tires (will need wider tires for riding on ungroomed sand / snow)

  • Accepts up to a 26x4.6” or 27.5x4.0” rear tire

  • MFG claimed weight = 26 lbs 3oz. (26.2 lbs)

    • 1+ lbs heavier than our GX builds w/ alloy wheelsets

    • 3+ lbs heavier than our XO1 builds w/ carbon wheelsets

    • 4.25+ lbs heavier than our ultimate AXS XO1 custom builds w/ carbon wheelsets

(Good bike, decent build kit. At $7099 USD / $10, 800 CAD, we can provide a comparable build for about $1k to $1.5k CAD less, and save 1-2 additional lbs. This is the closest online comparison to our custom build kits)

2025 SALSA BEARGREASE SLX

  • ASTM CAT3 rated

  • new frame design in 2019+ (uses classic geometry)

  • Same model release in 2025 as in 2022

  • Carbon frame and fork

  • 5 Frame sizes

  • SHIMANO SLX M7100 drivetrain

  • SRAM Guide T brakeset w/160mm rotors

  • Alloy wheelset, handlebar, crank, seatpost

  • 27.5x3.8” tires (will need wider tires for riding on ungroomed sand / snow)

  • Accepts up to a 26x4.6” or 27.5x4.0” rear tire

  • MFG posted weight = 28 lbs 12 oz. (28.75 lbs)

    • 3.5+ lbs heavier than our GX builds w/ alloy wheelsets

    • 5.5+ lbs heavier than our GX builds w/ carbon wheelsets

2025 MUKLUK C XT

  • ASTM CAT3 rated

  • Pre-2019 geometry

  • Same model release in 2025 as in 2022

  • Carbon frame and fork

  • 5 Frame sizes

  • SHIMANO SLX / XT drivetrain mix

  • SRAM G2 RS brakeset w/160mm rotors

  • Alloy wheelset, handlebar, crank, seatpost

  • 26x4.6” tires

  • Accepts up to a 26x4.8” or 27.5x4.0” rear tire

  • MFG est. weight by adding up listed components = 29.5-30.5 lbs

    • 4+ lbs heavier than our GX builds w/ alloy wheelsets

    • 6+ lbs heavier than our GX builds w/ carbon wheelsets

2025 TREK FARLEY 9.6 GX

  • ASTM CAT3 rated

  • Same frame design (geometry) since 2016

  • Carbon frame and fork

  • 4 Frame sizes

  • SRAM GX Eagle drivetrain

  • SRAM Level Brakeset, w/160mm rotors

  • Alloy wheelset, handlebar, crank, seatpost

  • 27.5x4.5” tires

  • MFG claimed weight = 28.91 lbs

  • VERIFIED weigh-in at Trek store = 29.2 lbs on showroom floor

    • 3.8+ lbs heavier than our GX builds w/ alloy wheelsets

    • 5.2+ lbs heavier than our GX builds w/ carbon wheelsets

2025 TREK FARLEY 7

  • ASTM CAT 3 rated

  • 2025 version retains updated TREK frame geometry from 2023+, now making it similar to the 9:ZERO:7 TUNDRA

  • TREK Alloy hardtail frame, w/ Manitou Mastodon COMP 80mm travel fork

  • 4 Frame sizes

  • SRAM NX / GX drivetrain + SRAM Level T hydraulic disc brakes

  • Tranz X dropper post

  • SUN Ringle Mulefut SL80 alloy wheelset + 27.5x4.50'' Bontrager Gnarwhal Team Issue Tires

  • MFG Claimed frame + carbon fork weight = 8.71 lbs

  • MFG Claimed complete bike weight = 37.59 lbs w/ Manitou COMP suspension fork

  • VERIFIED weigh-in at Trek store = 38.57 lbs on showroom floor

    • 6.5+ lbs heavier than our GX equipped 9:ZERO:7 TUNDRA (alloy) builds w/ alloy wheelsets, and Manitou Mastodon PRO 100mm travel forks

    • 8.75+ lbs heavier than our GX equipped OTSO VOYTEK or 9:ZERO:7 LYNX (carbon) builds w/ alloy wheelsets, and Manitou Mastodon PRO 100mm or 120mm travel forks.

    • 1+ lbs heavier than our GX equipped FOES MUTZ Full-Suspension builds w/150mm travel. (which makes this Trek hardtail weigh more than a full-suspension FOES MUTZ)

      • (Adding an ATOMIK PHATTY carbon wheelset to our builds, further lighten our OTSO, 9:ZERO:7 or FOES MUTZ fat bikes by an additional 1.5-2 lbs over stock Mulefut alloy wheelsets.)

2025 CANYON DUDE CF 8

  • ASTM CAT3 rating

  • Same frame design since 2015

  • Carbon frame and fork

  • 3 Frame sizes

  • SHIMANO Deore M6100 Drivetrain and Brakeset

  • Alloy wheelset, handlebar, crank, seatpost

  • 27.5x3.8” tires (will need wider tires for snow / sand use)

  • MFG claimed 13.7kg = 30.14 lbs

    • 5+ lbs heavier than our GX builds w/ alloy wheelsets

    • 7+ lbs heavier than our GX builds w/ carbon wheelsets

2025 ROCKY MOUNTAIN BLIZZARD CARBON 50

  • ASTM CAT3 rating

  • new frame design in 2020+ (progressive geometry)

  • Rocky Mountain filed for CCAA Restructuring on DEC 19 2024 (hopefully all goes well for this brand)

  • Carbon frame and fork

  • 4 Frame sizes

  • SRAM NX / GX Drivetrain

  • SRAM Level TL 2-piston brakes, w/160mm rotors

  • Alloy wheelset, handlebar, crank, seatpost

  • 27.5x4.5” tires

  • MFG claimed weight = 29.7 lbs

    • 4+ lbs heavier than our GX builds w/ alloy wheelsets

    • 6+ lbs heavier than our GX builds w/ carbon wheelsets

ASTM CAT 2 RATED FAT BIKES

Below is an example of a Fat bike that we do not sell, mostly due to safety concerns for our customers, who like to do a fair bit of extreme riding, competition racing, and/or expedition/adventure biking in adverse climates and terrain.

There are many Fat bikes out in the wild with only ASTM CAT 2 strength ratings, and most of their frame designs date back to 2015/16. “CAT2” Fat bikes were designed primarily for leisurely use in Sand and Snow conditions.

We will pick just one as an example, to show the difference in the expectations the manufacturer has for honoring their bicycle warranties, and conversely, what the acceptable riding conditions the owner is “allowed” to use their bike in, without potential damage or injury occurring due to riding outside “the bike’s intended purpose”.

BOREALIS CRESTONE EAGLE 12spd

  • ASTM CAT 2 rating (Sand, Snow, onRoad, Gravel, no jumping)

  • Same frame design since 2015

  • Carbon frame and fork

  • Alloy or carbon HED wheelset, or Carbon Borealis wheelset, handlebar and seatpost (all ASTM CAT 2 rated).

  • SRAM AXS XX1 Eagle 12spd avg. weight = 24+ lbs (setup tubeless) as shown in picture.

    • This is about 1.5-2.0 lbs more than our custom 21-23 lbs STAGE 3 AXS XO Eagle builds. In addition, all our Fat bikes are built to ASTM CAT 3+ strength ratings, which removes all the restrictive riding conditions (and potential safety issues) that a Crestone owner has to deal with, as clearly stated in their Borealis Warranty.

    BOREALIS WARRANTY

    • catastrophic failure may occur to Borealis-branded parts if rider+gear weight exceeds 230 lbs

    • Component Disclaimer : “some bicycles and components are built to be lightweight, which means they may not be appropriate for riders who are approaching 230 pounds in weight. Riders approaching 230 pounds in weight should not ride any bicycle equipped with BOREALIS-branded composite seat posts, handlebar stems, or handlebars.”

    • “Misuse/Misapplication” warranty warning states that Borealis Carbon rims are NOT rated for rider+gear weight of 230+ lbs and are NOT rated for Trail/AM use.

    • Frameset Disclaimer : “This bicycle or frameset has not been designed, engineered, distributed, manufactured, or retailed for uses in trick riding, ramp riding, jumping, aggressive riding, riding on severe terrain, riding in severe climates, riding with heavy loads, commercial activities, or any similar activities; such uses may damage the bicycle, can cause serious injury to the rider, and in all cases will void this warranty.“

Page Summary :

  • Example of an ASTM “CAT2” fat bike frame/component warranty : link : < Borealis Bikes >

  • Example of an ASTM “CAT3” fat bike frame/component warranty : link : < 9:ZERO:7 Bikes >

  • Our STAGE 1/2/3 custom carbon Fat bike builds usually run 3-7 lbs lighter than the competition’s best stock builds, and are built as strong or stronger than the best they offer. All our custom builds start at ASTM CAT 3/4/5.

  • Our design goals are high-performance, durability and safety first - that’s why we choose the OTSO VOYTEK, 9:ZERO:7 LYNX/TUNDRA and FOES MUTZ for all our fat bike builds.