Trek Top Fuel 8 Gen 4 Mountain Bike 2026 - Trail Full Suspension MTB
This alloy full-sus rig climbs well, handles descents confidently, and delivers proven trail tech where it counts.
Key Features
- Alpha Platinum Aluminium frame with 4-way Mino Link and 120 mm rear travel
- Fox Rhythm 34 Float EVOL fork with GRIP damper, 130 mm travel
- Fox Performance Float DPS rear shock with 3-position damper, 120 mm travel
- Shimano XT/SLX 12-speed drivetrain for crisp, wide-range shifting
- Shimano M6120 4-piston hydraulic disc brakes for powerful stopping
- 29" wheels with Bontrager Gunnison Pro XR Tubeless Ready tyres
- Internal frame storage and dropper post for technical trail control
- Available with 0% APR finance
The Trek Top Fuel 8 Gen 4 is a do-it-all trail bike that’s as confident climbing big days out as it is taking on rooty descents. With 130 mm of front travel and 120 mm at the rear, it’s built to keep things smooth and controlled without soaking up all your pedalling power – ideal for riders who want efficiency and versatility.
The Alpha Platinum Aluminium frame keeps weight low and durability high, with internal cable routing and Trek’s built-in downtube storage for carrying spares or snacks. The standout 4-way Mino Link system lets you tweak geometry and suspension leverage to suit your riding style or trail conditions.
At the front, a Fox Rhythm 34 fork with Float EVOL air spring and GRIP damper handles rocky hits and rough sections with control. The rear end gets 120 mm of plush, responsive travel from a Fox Performance Float DPS shock, helping to keep the bike balanced and composed.
The Shimano XT/SLX 12-speed drivetrain provides slick shifting and plenty of range, backed up by a Shimano M6120 4-piston hydraulic disc brake setup that brings big stopping power when the trail demands it. Bontrager Line Comp 30 wheels are Tubeless Ready and wrapped in 2.4" Bontrager Gunnison Pro XR tyres for a solid grip and fast rolling feel across a range of trail surfaces.
Other highlights include a Bontrager Line dropper post for quick saddle height changes, a comfortable Bontrager saddle and bars, and upgrade-ready frame design with space for bigger forks, longer shocks, and even longer dropper posts if needed.
If you’re looking for a trail bike that delivers performance, adjustability and value in one tough alloy package, the Top Fuel 8 Gen 4 is up for everything from big climbs to session laps.
Occasionally, without notice, manufacturers change product design and/or specifications.
| Frame | Alpha Platinum Aluminium, internal storage, tapered head tube, internal guided routing, downtube guard, alloy rocker link, 4-way Mino Link, ABP, Boost148, 120 mm travel |
| Fork | Fox Rhythm 34, Float EVOL air spring, GRIP damper, tapered steerer, 44 mm offset, Boost110, 15 mm Kabolt axle, 130 mm travel |
| Rear Shock | Fox Performance Float DPS, 3-position damper, 185 mm x 50 mm |
| Stem | Bontrager Elite, 35 mm, 0-degree, 45 mm length |
| Bars | Bontrager Line, alloy, 35 mm, 27.5 mm rise, 780 mm width |
| Front Brake | Shimano 4-piston hydraulic disc, M6100 lever, M6120 calliper // Shimano 4-piston hydraulic disc, M6100 lever, M6120 calliper |
| Rear Brake | Shimano 4-piston hydraulic disc, M6100 lever, M6120 calliper // Shimano 4-piston hydraulic disc, M6100 lever, M6120 calliper |
| Rear Mech | Shimano XT M8100, long cage |
| Shifters | Shimano XT M8100, 12-speed |
| Speed | 12 |
| Rims | Bontrager Line Comp 30 |
| Front Hub | Bontrager Line Comp 30 |
| Rear Hub | Bontrager Line Comp 30 |
| Front Tyre | Bontrager Gunnison Pro XR, Tubeless Ready, dual compound, aramid bead, 60 tpi, 29x2.40" |
| Rear Tyre | Bontrager Gunnison Pro XR, Tubeless Ready, dual compound, aramid bead, 60 tpi, 29x2.40" |
| Seat Post | Bontrager Line Dropper, 170 mm travel, MaxFlow, internal routing, 34.9 mm, 450 mm length |
| Saddle | Bontrager Verse P3, chromoly rails |
| Chainset | Shimano Deore M6120, 30T ring, 55 mm chainline, 170 mm length |
| Bottom Bracket | Shimano BB-MT501 BSA |
| Chain | Shimano SLX M7100, 12-speed |
| Cassette | Shimano SLX M7100, 10-51T, 12-speed |
Trek Top Fuel Gen 4 Size Chart
| Size | Height cm | Height Feet / Inches | Inseam cm | Inseam Inches |
|---|---|---|---|---|
| XS | 145 - 155 cm | 4'9" - 5'1" | 69 - 73 cm | 27" - 29" |
| S | 155 - 165 cm | 5'1" - 5'5" | 74 - 78 cm | 29" - 31" |
| M | 165 - 176 cm | 5'5" - 5'9" | 79 - 83 cm | 31" - 33" |
| ML | 173 - 180 cm | 5'8" - 5'11" | 81 - 86 cm | 32" - 34" |
| L | 177 - 188 cm | 5'10" - 6'2" | 84 - 89 cm | 33" - 35" |
| XL | 188 - 195 cm | 6'2" - 6'5" | 89 - 91 cm | 35" - 36" |
What size frame do I need if I am between sizes? - read here
Trek Top Fuel Gen 4 Geometry Chart
| Size | M (High) | M (Low) | ML (High) | ML (Low) | L (High) | L (Low) | XL (High) | XL (Low) |
|---|---|---|---|---|---|---|---|---|
| Stack | 599 | 603 | 604 | 607 | 608 | 612 | 626 | 630 |
| Reach | 452 | 447 | 462 | 456 | 470 | 464 | 485 | 479 |
| Head Tube Length | 105 | 105 | 110 | 110 | 115 | 115 | 135 | 135 |
| Head Tube Angle | 65.9° | 65.5° | 65.9° | 65.5° | 65.9° | 65.5° | 65.9° | 65.5° |
| Bottom Bracket Drop | 26 | 32 | 26 | 32 | 26 | 32 | 26 | 32 |
| Fork Rake/Offset | 43 | 43 | 43 | 43 | 43 | 43 | 43 | 43 |
| Trail | 121 | 125 | 121 | 125 | 121 | 125 | 121 | 125 |
| Chainstay Length | 434 | 435 | 439 | 440 | 440 | 440 | 444 | 445 |
| Wheelbase | 1188 | 1188 | 1210 | 1210 | 1227 | 1227 | 1270 | 1271 |
| Top Tube Length (horizontal) | 587 | 588 | 611 | 612 | 630 | 631 | 672 | 673 |
| Standover Height | 755 | 750 | 755 | 750 | 760 | 755 | 765 | 760 |
| Seat Tube Length | 410 | 410 | 420 | 420 | 435 | 435 | 470 | 470 |
| Seat Tube Angle | 70.5° | 70.0° | 70.5° | 70.0° | 70.5° | 70.0° | 70.5° | 70.0° |
| Effective Seat Tube Angle | 77.3° | 76.9° | 76.6° | 76.2° | 76.3° | 75.9° | 75.6° | 75.2° |
All measurements are in mm unless otherwise stated.
The above table shows the standard geometry for the bicycle as shipped, other geometry configurations may be available with certain bikes. Please contact us via Live Chat to find out more.
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Trek Top Fuel 8 Gen 4 Mountain Bike 2026 - Trail Full Suspension MTB
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