Trek Top Fuel 8 Gen 4 - 2025
Details
Top Fuel 8 Gen 4 is a nimble alloy trail bike that strikes a balance between quick climbing efficiency and descending confidence. It packs in a versatile 130mm front and 120mm rear travel for ripping over rocks and roots without sacrificing power on ascents. It's built from lightweight Alpha Platinum Aluminum that helps save your budget for bike trips, but packs in upgrades where they matter, like a 12-speed Shimano XT and SLX drivetrain, and a Fox Rhythm 34 fork.
IT'S RIGHT FOR YOU IF…
You want an alloy full suspension that's ready to rip. You like to ride everything from cross-country hot laps to all-mountain adventures, and you need a bike that's light, versatile, and confident. You've got an appreciation for the durability of aluminum, but want upgrades where they matter, like your drivetrain and suspension.
THE TECH YOU GET
An Alpha Platinum Aluminum frame equipped with a 4-way Mino Link lower shock mount for tweaking geometry and suspension leverage rate. A 130mm FOX Rhythm 34 fork with Float EVOL air spring and GRIP damper, plus 120mm of rear travel from a FOX Performance Float shock with a 3-position damper. It's topped off with a Shimano XT/SLX 12-speed groupset, hydraulic disc brakes, a Bontrager Line dropper post, and Tubeless Ready Bontrager Line Comp 30 wheels.
THE FINAL WORD
Top Fuel 8 Gen 4 is ready to cut loose from all-day climbs to rooty descents. It balances capability and efficiency, with just enough travel to keep the ride smooth without eating up your pedaling power. It gives you the perfect blend of affordability, with a rugged alloy frame, and upgrades where they matter, like the Shimano XT/SLX drivetrain.
WHY YOU'LL LOVE IT
- Its lightweight frame and versatile geometry make it the perfect choice for all kinds of rides and all kinds of riders
- The 4-way Mino Link makes it easy to adjust your geometry or leverage rate for how and where you want to ride
- You get a sweet balance of price and performance with upgraded components and a rugged alloy frame
- The Alpha Platinum Aluminum frame is robust, yet light, and packs in updated internal frame storage for easy access to gear and snacks
- It's more upgrade-ready than ever, with room for bigger 140mm forks and longer-stroke shocks for up to 130mm of rear travel, plus room for extra-long dropper posts
| Frame Size | Small | Medium | Medium / Large | Large | X-Large |
|---|---|---|---|---|---|
| Geometry position | High / Low | High / Low | High / Low | High / Low | High / Low |
| Seat tube (cm) | 36 | 41 | 42 | 43.5 | 47 |
| Seat tube angle | 69.5° / 69° | 70.5° / 70° | 70.5° / 70° | 70.5° / 70° | 70.5° / 70° |
| Effective seat tube angle | 76.5° / 76° | 77.3° / 76.9° | 76.6° / 76.2 | 76.3° / 75.9° | 75.6° / 75.2° |
| Head tube length (cm) | 10.5 | 10.5 | 11 | 11.5 | 13.5 |
| Head angle | 65.9° / 65.5° | 65.9° / 65.5° | 65.9° / 65.5 | 65.9° / 65.5° | 65.9° / 65.5° |
| Effective top tube (cm) | 55.8 / 55.9 | 58.7 / 58.8 | 61.1 / 61.2 | 63 / 63.1 | 67.2 / 67.3 |
| Bottom bracket drop (cm) | 1 / 1.6 | 2.6 / 3.2 | 2.6 / 3.2 | 2.6 / 3.2 | 2.6 / 3.2 |
| Chainstay length (cm) | 43.4 / 43.5 | 43.4 / 43.5 | 43.9 / 44 | 43.9 / 44 | 44.4 / 44.5 |
| Offset (cm) | 4.3 | 4.3 | 4.3 | 4.3 | 4.3 |
| Trail (cm) | 11.1 / 11.5 | 12.1 / 12.5 | 12.1 / 12.5 | 12.1 / 12.5 | 12.1 / 12.5 |
| Wheelbase (cm) | 115 / 115.1 | 118.8 / 118.8 | 121 / 121 | 122.7 / 122.7 | 127 / 127.1 |
| Standover (cm) | 70.5 / 70 | 75.5 / 75 | 75.7 / 75.2 | 75.8 / 75.3 | 76.3 / 75.8 |
| Frame reach (cm) | 42.2 / 41.7 | 45.2 / 44.7 | 46.7 / 46.2 | 48.2 / 47.7 | 51.2 / 50.7 |
| Frame stack (cm) | 56.6 / 57 | 59.9 / 60.3 | 60.4 / 60.7 | 60.8 / 61.2 | 62.6 / 63 |
| Frame Size | Rider Height (cm)Rider HEight (cm) | Rider Height (in) |
|---|---|---|
| Small | 155 - 165 | 5'1" - 5'5" |
| Medium | 165 - 176 | 5'5" - 5'9" |
| Medium / Large | 173 - 180 | 5'8" - 5'11" |
| Large | 177 - 188 | 5'10" - 6'2" |
| X-Large | 188 - 195 | 6'2" - 6'5" |
Specs
| Pedals | Sold Separately |
|---|---|
| Fork | Fox Rhythm 34, Float EVOL air spring, GRIP damper, tapered steerer, 44mm offset, Boost110, 15mm Kabolt axle, 130mm travel |
| Stem | Bontrager Elite, 35mm, 0 degree, 45mm length |
| Chain | Shimano SLX M7100, 12 speed |
| Frame | Alpha Platinum Aluminum, internal storage, tapered head tube, internal guided routing, downtube guard, OCLV Next rocker link, Mino 4 link, ABP, Boost148, 120mm travel |
| Tires | Bontrager Gunnison Pro XR, Tubeless Ready, wire bead, 60 tpi, 27.5x2.40'' |
| Brakes | Shimano 4-piston hydraulic disc, M6100 lever, M6120 caliper // Shimano 4-piston hydraulic disc, M6100 lever, M6120 caliper |
| Rotors | Shimano RT66, 6-bolt, 180mm |
| Saddle | Bontrager Verse P3, chromoly rails |
| Crankset | Shimano Deore M6120, 30T ring, 55mm chainline, 170mm length |
| Seatpost | Bontrager Line Dropper, 100mm travel, MaxFlow, internal routing, 34.9mm, 310mm length |
| Shifters | Shimano XT M8100, 12 speed |
| Handlebars | Bontrager Line, alloy, 35mm, 27.5mm rise, 780mm width |
| Tape/Grips | Bontrager XR Trail Comp, nylon lock-on |
| Rear Derailleur | Shimano XT M8100, long cage |
| Cassette/Freewheel | Shimano SLX M7100, 10-51T, 12 speed |
| Wheels | Bontrager Line Comp 30, High Strength 6000 Series Aluminum rim, Tubeless Ready, Rapid Drive 108, 6-bolt, Shimano MicroSpline freehub, Boost148, 12mm thru axle, 27.5'' |
| Rear Shock | Fox Performance Float DPS, 2-position damper, 185mm x 50mm |
| Bottom Bracket | Shimano BB-MT501 BSA |
* Subject to change without notice.
Part Numbers
| Option | UPC | MPN | Store SKU |
|---|---|---|---|
| Lichen Green / Large / 29-inch | 197216022374 | 5319321 | TOP20389079N |
| Matte Dark Web / Small / 27.5-inch | 197216022299 | 5319313 | TOP24804756B |
| Lichen Green / X-Large / 29-inch | 197216022381 | 5319322 | TOP21409231N |
| Matte Dark Web / X-Large / 29-inch | 197216022336 | 5319317 | TOP22974657B |
| Matte Dark Web / Medium/Large / 29-inch | 197216022312 | 5319315 | TOP22152873B |
| Matte Dark Web / Medium / 29-inch | 197216022305 | 5319314 | TOP21996912B |
Reviews
