Fuel MX 9.8 XT Di2 Gen 7

The Gen 7 Trek Fuel MX is the more aggressive mixed-wheel expression of Trek’s new shared Fuel platform. Rather than building a separate frame around a mullet layout, Trek uses one chassis for the Fuel EX, Fuel MX, and Fuel LX, then changes rocker links, the lower shock mount, and relevant wheel and suspension parts to create each configuration. In MX form, that yields a 29-inch front wheel, 27.5-inch rear wheel, 150mm of rear travel, and a 160mm fork—placing it squarely in the modern all-mountain category for riders who want more maneuverability and rear-wheel clearance than a full 29er without stepping into a full enduro bike.

What distinguishes this generation is not just the wheel format, but the underlying platform update. Gen 7 adds more dropper-post insertion depth, lower standover, more front-triangle clearance, improved in-frame storage, quieter routing and frame protection, a standard ZS headset for angle-adjust compatibility, and UDH support, while retaining Trek’s ABP suspension layout. That makes the Fuel MX notable as a configurable platform bike rather than a one-off niche model: it targets riders who prioritize a playful, quicker-handling setup, but it does so with the same modern frame standards and practical features expected in the upper middle of the all-mountain market.

$6,500Gen Gen 7
Trek Fuel MX 9.8 XT Di2 Gen 7
Build
Size

Inventory

Stack627mm
Reach456mm
Top tube584mm
Headtube length110mm
Standover height747mm
Seat tube length400mm

Fit and geometry

The Fuel MX’s geometry is clearly aimed at aggressive trail and all-mountain riding. Across the size range, the head tube angle is a consistent 64.2 degrees, paired with 132mm of trail, which points to stable front-end behavior at speed and on steeper descents. Reach numbers are contemporary without being extreme—456mm in Medium, 482mm in Large, and 507mm in XL—while stack heights of 627mm, 641mm, and 654mm respectively suggest a reasonably tall front end suited to descending confidence more than low-slung XC positioning.

Chainstay length grows with size, from 434mm on S and M to 449mm on XXL, helping preserve weight balance as front-center increases. Wheelbase follows suit, stretching from 1191mm in S to 1332mm in XXL, which should give larger sizes consistent stability rather than feeling disproportionately short at the rear. The 31mm BB drop is moderate for a mixed-wheel bike, balancing cornering stability with pedal clearance, while the listed 72.3-degree seat tube angle is relatively slack by current standards on paper; in practice, riders sensitive to seated climbing position may pay close attention to fit and saddle setup, especially on longer climbs.

Full specs

Frameset

Frame

OCLV Mountain Carbon, internal storage, ZS headset, adjustable leverage rate, guided internal routing, interchangeable alloy rocker link, interchangeable lower shock mount, downtube guard, shuttle guard, BSA 73, ISCG 05, ABP, UDH, Boost148, adaptable travel 145mm-160mm

Fork

Fox Factory 36, Float EVOL air spring, GRIP X2 damper, 44mm offset, Boost110, 15mm Kabolt X axle, 160mm travel

Rear shock

Fox Factory Float X, 205mm x 60mm

Weight

M - 15.09 kg / 33.27 lbs (with TLR sealant, no tubes)

Groupset

Shift levers

Shimano XT Di2 M8250, 12-speed

Rear derailleur

Shimano XT M8250, long cage

Cassette

Shimano XT M8200, 12-speed, 10-51T

Chain

Shimano Ultegra/XT M8100

Crankset

Shimano XT 8200, 30T, 55mm chainline, 170mm length

Bottom bracket

Shimano BB-MT501 BSA

Front brake

Shimano XT M8220 4-piston hydraulic disc

Rear brake

Shimano XT M8220 4-piston hydraulic disc

Front rotor

Shimano RT86, 6-bolt, 203mm

Rear rotor

Shimano RT86, 6-bolt, 180mm

Wheelset

Front wheel

Bontrager Line Comp 30, Tubeless Ready, 6-bolt, Boost110, 15mm thru axle, 29in

Rear wheel

Bontrager Line Comp 30, Tubeless Ready, Rapid Drive 108, 6-bolt, Shimano Micro Spline freehub, Boost148, 12mm thru axle, 27.5in

Front tire

Maxxis Assegai, Tubeless Ready, 3C, EXO+ casing, MAXXGRIP, folding bead, 29x2.5

Rear tire

Maxxis Minion DHR II, Tubeless Ready, 3C, EXO+ casing, MAXXTERRA, folding bead, 27.5x2.5

Cockpit

Stem

Bontrager Elite, 35mm, 0 degree, 45mm length

Handlebars

Race Face ERA, carbon, 35mm clamp, 40mm rise, 800mm width

Saddle

Verse Short Pro, carbon rails, 145mm width

Seatpost

Bontrager Line Dropper (S: 150mm travel/410mm length; M: 170mm travel/450mm length; L-XXL: 200mm travel/515mm length), MaxFlow, internal routing, 34.9mm

Grips

Trek Line Elite, lock-on

Builds

The Fuel MX Gen 7 range starts at $4,999.99 and runs to $8,499.99, with Trek offering multiple drivetrain paths at the same price points rather than forcing riders into a single spec philosophy. At the entry level, the 9 XT Gen 7 and 9 Eagle 90 Gen 7 both sit at $4,999.99, followed by the 9 XT Di2 Gen 7 at $5,499.99. The $5,999.99 tier is especially broad, with 9.8 XT Gen 7, 9.8 Eagle 90 Gen 7, and 9 X0 AXS Gen 7 all available at the same price, before stepping up to the 9.8 XT Di2 Gen 7 at $6,499.99 and the flagship 9.9 X0 AXS Gen 7 at $8,499.99.

From the naming alone, the lineup’s main differentiators are drivetrain families and frame/material tiering, with Shimano XT, Shimano XT Di2, SRAM Eagle 90, and SRAM X0 AXS represented across the range. That gives buyers a clear choice between mechanical and electronic shifting, and between Shimano and SRAM ecosystems, without a large penalty until the top-end 9.9 build. The strongest value on paper is likely in the dense $5,999.99 middle of the range, where Trek offers several distinct component directions at the same price rather than reserving meaningful choice only for premium builds.