Top Fuel 9.8 XT Di2 Gen 4
OverviewAbout the Trek Top Fuel 9.8 XT Di2 Gen 4
The Trek Top Fuel 9.8 XT Di2 Gen 4 is a mountain bike, built on a carbon frame, listed at $7,999.99. An off-road bike for trails, with grippy tyres and trail-ready geometry.
SizingWhat size Top Fuel 9.8 XT Di2 Gen 4 do I need?
Enter your height to see the size Trek recommends.
| Size | Rider height | In feet | Inseam |
|---|---|---|---|
| S | 155 to 165 cm | 5 ft 1 in to 5 ft 5 in | 74 to 78 cm |
| M | 165 to 177 cm | 5 ft 5 in to 5 ft 10 in | 79 to 83 cm |
| ML | 173 to 180 cm | 5 ft 8 in to 5 ft 11 in | 81 to 86 cm |
| L | 177 to 188 cm | 5 ft 10 in to 6 ft 2 in | 84 to 89 cm |
| XL | 188 to 195 cm | 6 ft 2 in to 6 ft 5 in | 89 to 91 cm |
Rider heights from Trek's size chart. Height is a starting point: arm and leg length, flexibility and riding style all matter, so a test ride beats any chart. How bike sizing works.
SpecificationsWhat we know
- Brand
- Trek
- Model year
- 2026
- Category
- Mountain
- Frame
- Carbon
- Wheel size
- 29-inch
- Drivetrain
- Shimano XT Di2 1x12
- Brakes
- Disc
- Frame sizes
- S, M, ML, L, XL
- Price
- $7,999.99, RRP AUD (Trek Australia, checked 16 Oct 2026)
Specs and pricing are listed in AUD and sourced from Australian retail listings. Confirm the current details and availability with the seller before purchase.
GeometrySize M
- Stack
- 599 mm
- Reach
- 452 mm
- Stack/reach
- 1.33
- Head angle
- 65.9 deg
- Seat angle
- 77.3 deg
- Wheelbase
- 1188 mm
- Chainstay
- 434 mm
- BB drop
- 26 mm
- Standover
- 755 mm
- Fork rake
- 43 mm
GearingRatios
Ratios are derived from the chainrings and cassette. They describe the gearing, not any rider's ability.
Drivetrain & buildFull specification
- Groupset
- Shimano XT Di2
- Shifting
- Electronic
- Drive
- 1x
- Speeds
- 12
- Crank
- Shimano XT 8200, 30T, 55 mm chain-line, 170 mm length
- Chainrings
- 30
- Cassette
- Shimano XT M8200, 10-51, 12-speed
- Rear derailleur
- Shimano XT M8250, long cage
- Brakes
- Shimano XT M8220 4-piston hydraulic disc
- Rotors
- 180mm
- Wheelset
- Bontrager Line Comp 30, Tubeless Ready, 6-bolt, Boost110, 15 mm thru-axle, 27.5"
- Stock tyre
- 29x2.40
- Tubeless
- Yes
- Fork material
- RockShox Pike Select+, DebonAir spring, Charger 3.1 RC2 damper, tapered steerer, 44 mm offset, Boost110, 15 mm Maxle Stealth, 130 mm travel
- BB standard
- Shimano BB-MT501 BSA
- Seatpost
- Bontrager Line Dropper, 170 mm travel, MaxFlow, internal routing, 34.9 mm, 450 mm length
- Cockpit
- Bontrager Line Pro, 35 mm, Blendr-compatible, 0-degree, 35 mm length / Bontrager Line Pro, OCLV Carbon, 35 mm, 27.5 mm rise, 780 mm width
- Saddle
- Verse Short Comp, steel rails, 145 mm width
SuspensionMTB detail
- Front travel
- 130 mm
- Rear travel
- 120 mm
- Fork
- RockShox Pike Select+
- Shock
- RockShox Deluxe Ultimate RCT
- Wheel config
- 29
- Dropper
- Bontrager Line Dropper
- Dropper travel
- 170 mm
- Discipline
- Downcountry
- Suspension
- full suspension
Bike DNAWhat the numbers say
- Steering
- A 65.9 deg head angle points to slack, trail and enduro handling.
- Climbing
- Lowest ratio 0.59 is a very low climbing gear for steep or loaded climbs.
Derived from the published geometry and gearing above. It describes the numbers, not a ride test.
BikeFinder Data Profile: geometry and specification researched from published sources (Trek Australia product data 52231 (spec list, geometry chart, size chart)), verified 2026-10-16. This is a specification analysis, not a physical ride review.
Where to buyStockist
BikeFinder is an independent directory. We link to retailers; prices and stock are set by the seller and shown as at the date checked.
