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.
 |  |  |
| MSRP | $2,800 | $2,599 | $2,449 |
|---|---|---|---|
| Spec Level | |||
| Where to Buy | — $1 At | — $1 At | — $1 At |
| Category | Trail | Enduro | Trail |
| Weight | 33.5 lbs | 34.6 lbs | |
| Frame | Aluminum | Aluminum | Aluminum |
| Fork | RockShox 35 Silver | Fox Rhythm Float 34 | RockShox Recon Silver RL |
| Wheels | Aluminum | Aluminum | Aluminum |
| Wheel Size | 29″ | 27.5″ / 29″ | 27.5″ / 29″ |
| Brakes | Hydraulic Disc | Hydraulic Disc | Hydraulic Disc |
| Groupset | SX Eagle | SLX, Shimano | Deore |
| Drivetrain | 1 × 12 | 1 × 12 | 1 × 12 |
| Suspension | Full | Full | Full |
| Front Travel | 140mm | 150mm | 140mm |
| Rear Travel | 130mm | 150mm | 130mm |
| Seatpost | Dropper | Dropper | Dropper |
| Brand Site | specialized.com | polygonbikes.com | trekbikes.com |
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Based on build material and quality level of the frame, fork, wheelset, groupset, suspension system, and more. Learn more →
| 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 |
| 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 |
| 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 |