Bike Comparison

The Specialized Stumpjumper Alloy, Polygon SISKIU T8, and Trek Fuel EX 5 are all aluminum frame full suspension mountain bikes. The Stumpjumper Alloy has 29″ aluminum wheels and better components, while the SISKIU T8 has a better fork and more travel. Explore the differences below.

    2022 Specialized Stumpjumper Alloy
    2022 Polygon SISKIU T8
    2022 Trek Fuel EX 5
    MSRP$2,800$2,599$2,449
    Spec Level
    Where to Buy
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    CategoryTrailEnduroTrail
    Weight33.5 lbs34.6 lbs
    FrameAluminumAluminumAluminum
    ForkRockShox 35 SilverFox Rhythm Float 34RockShox Recon Silver RL
    WheelsAluminumAluminumAluminum
    Wheel Size29″27.5″ / 29″27.5″ / 29″
    BrakesHydraulic DiscHydraulic DiscHydraulic Disc
    GroupsetSX EagleSLX, ShimanoDeore
    Drivetrain1 × 121 × 121 × 12
    SuspensionFullFullFull
    Front Travel140mm150mm140mm
    Rear Travel130mm150mm130mm
    SeatpostDropperDropperDropper
    Brand Sitespecialized.compolygonbikes.comtrekbikes.com

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    Spec Level

    Based on build material and quality level of the frame, fork, wheelset, groupset, suspension system, and more. Learn more »

    Spec level →$0$500$1,000$1,500$2,000$2,500
    Stumpjumper Alloy
    SISKIU T8
    Fuel EX 5

    Gear Range

    Specialized Stumpjumper Alloy

    24 mph

    Polygon SISKIU T8

    24 mph

    Trek Fuel EX 5

    26 mph

    Learn More


    Geometry

    Specs
    Frame

    Alloy chassis and rear-end, asymmetrical design, 29 Trail Geometry, horst pivot BB adjustment, threaded BB, 12x148mm dropouts, sealed cartridge bearing pivots, replaceable derailleur hanger, 130mm of travel

    ALX TRAIL ENDURO 150mm (27.5") / 140mm (29") TRAVEL

    aluminum frame

    Fork

    RockShox 35 Silver, Solo Air, 44mm offset, rebound adjust, TurnKey lockout, 15x110mm Boost™ Maxle® Lite thru-axle, 140mm of travel

    FOX 34 RHYTHM 150mm (27.5") / 140mm (29") TRAVEL

    RockShox Recon Silver, Solo Air spring, Motion Control damper, lockout, tapered steerer, 42mm offset, Boost110, Maxle Stealth, 140mm travel

    Rear Shock

    X-Fusion 02 Pro RL, Rx Trail Tune, rebound adjust, lockout S1:190x42.5mm, S2-S6: 190x45mm

    FOX FLOAT DPS SPECIAL TUNING E2E:210X55MM, HARDWARE:8MMX25MM

    Size: XS, S, X-Fusion Pro 2, 2-position damper, 210mm x 52.5mm; Size: S, M, ML, L, XL, X-Fusion Pro 2, 2-position damper, 210mm x 55mm

    Bottom Bracket

    SRAM Powerspline

    SHIMANO 2-PIECE CRANKSET BSA THREADED

    Shimano MT500, 92mm, PressFit

    Headset

    ZERO STACK (ZS) SEALED BEARING FOR TAPER HEAD TUBE, ZS 44/28.6 | ZS 56/40

    Knock Block Integrated, 58-degree radius, cartridge bearing, 1-1/8'' top, 1.5'' bottom

    Stem

    Alloy Trail Stem, 35mm bar bore

    ENTITY XPERT, ALLOY E:35MM R:7DEG BB:35MM

    Bontrager Rhythm Comp, 31.8mm, Knock Block, 0 degree, 50mm length

    Handlebar

    Specialized, 6061 alloy, 6-degree upsweep, 8-degree backsweep, 30mm rise, 780mm width

    ENTITY XPERT, ALLOY W:780MM R:20MM BB:35MM

    Bontrager alloy, 31.8mm, 15mm rise, 750mm width

    Saddle

    Body Geometry Bridge Saddle, steel rails

    ENTITY XTENT

    Bontrager Arvada, steel rails, 138mm width

    Seatpost

    TranzX dropper, 34.9mm, S1: 100mm, S2: 125mm, S3: 150mm. S4-S5: 170mm, S6- 200mm

    TRANZ-X 150MM (S-M) 170 (L-XL) TRAVEL, ZERO OFFSET, 30.9MM

    Size: XS, S, TranzX JD-YSP18, 100mm travel, internal routing, 31.6mm, 361mm length; Size: M, ML, L, XL, TranzX JD-YSP18, 130mm travel, internal routing, 31.6mm, 425mm length

    Pedals

    Alloy Flat with Pins

    Grips

    Bontrager XR Trail Comp, nylon lock-on

    Groupset
    Rear Derailleur

    SRAM SX Eagle, 12-speed

    SHIMANO SLX RD-M7100-SGS DIRECT ATTACH

    Shimano Deore M6100, long cage

    Crank

    SRAM SX Eagle, S1:165mm, S2-S5: 170mm, S6: 175mm, 30T

    SHIMANO MT-510-1 BOOST 32T

    Size: XS, S, M, ML, L, Shimano MT511, 30T steel ring, 52mm chainline, 170mm length; Size: M, ML, L, XL, Shimano MT511, 30T steel ring, 52mm chainline, 175mm length

    Shifters

    SRAM SX Eagle, trigger, 12-speed

    SHIMANO SLX SL-M7100-R, 1x12-SPEED TRIGGER

    Shimano Deore M6100, 12 speed

    Cassette

    SRAM PG-1210 Eagle, 11-50t

    12 SPEED 11-51T

    Shimano Deore M6100, 10-51, 12 speed

    Chain

    SRAM SX Eagle, 12-speed

    KMC X12 12SPEED

    Shimano Deore M6100, 12 speed

    Brakes

    Tektro Gemini Comp, hydraulic disc, resin pad, 200mm

    TEKTRO HD-M745 4-PISTONS HYDRAULIC DISC BRAKES

    Shimano hydraulic disc, MT201 lever, MT200 caliper

    Wheels
    Rims

    Double-wall alloy, 27mm internal width, 28h

    584 / 622-35 32H FOR TYRE 584 / 622-54/76 TUBELESS READY

    Alex MD35, tubeless compatible, 32-hole, 35mm width, presta valve

    Spokes

    Stainless, 14g

    14g stainless steel

    Front Hub

    Alloy, sealed cartridge bearings, 15x110mm thru-axle, 28h

    Shimano HB-MT410, Thru Axle 15x110mm 32h, Center-Lock

    Bontrager alloy, 6-bolt, Boost110, 15mm thru axle

    Rear Hub

    Alloy, sealed cartridge bearings, 12x148mm thru-axle, 28h

    Shimano FB-MT410, Thru Axle 12x148mm 32h, Center-Lock, Microspline Hub

    Size: XS, S, M, ML, L, XL, Bontrager alloy, sealed bearing, alloy axle, 6-bolt, Shimano MicroSpline freehub, Boost148, 12mm thru axle; Size: XS, S, M, ML, L, XL, Bontrager alloy, sealed bearing, 6-bolt, Shimano MicroSpline freehub, Boost148, 12mm thru axle

    Tires

    Front: Butcher, GRID casing, GRIPTON® T7 compound, 29x2.3", Rear: Purgatory, GRID casing, GRIPTON® T7 compound, 29x2.3"

    PERFORMANCE TIRE, 27.5”X2.40” / 29”X2.40”

    Size: XS, S, Bontrager XR4 Comp, wire bead, 30 tpi, 27.5x2.60''; Size: S, M, ML, L, XL, Bontrager XR4 Comp, wire bead, 30 tpi, 29x2.60''

    Disk Rotors

    SHIMANO SM-RT54 180mm CENTER-LOCK

    Shimano RT56, 6-bolt, 180mm