Top Fuel 9.8 GX AXS Gen 4 - Trek Bikes (INE)

Overview

"The Top Fuel manages to feel quick and efficient without any harshness, a feat that's not easy to accomplish."

"The added ability to fiddle, with not just head/seat angle and BB height, but also play with shock progression AND maybe even long-stroke the bike for more travel is appealing."

"Mind you, it only took a few pedal strokes to appreciate the Top Fuel’s efficient and responsive demeanour.[...] Heading across rockier singletrack, the new bike is noticeably sprightlier and springier than its predecessor."

"I keep finding myself on top of bigger moves than Trek would probably recommend for the Top Fuel, and I keep bouncing out the bottom even more in love with the bike."

"... the Top Fuel stands out for being just a touch more composed and forgiving (in terms of its suspension performance) than most of the bikes that it compares most directly to on paper."

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Time to get out the repair stand for some maintenance? Find a detailed breakdown of your bike with part numbers, torque values and platform-specific tech instructions below.

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Save some cash on the light and fast Top Fuel Gen 3, or go even lighter with more adjustability with Top Fuel Gen 4

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Features

Opt for light parts and a 120 mm fork for a featherweight Top Fuel, or a 140 mm fork and longer-stroke 130 mm rear shock for extra versatility. Room for a longer dropper and MX wheels lets you customise the Top Fuel into an ultimate playful trail whip.

Easily adjust the suspension and geometry four different ways for where and how you ride. At the flip of a coin, you can ride with more or less progressive suspension and tweak your geometry for a slacker head tube and lower BB, or steeper head tube and higher BB.

New internal frame storage bags make it easy to ditch the pack and still carry your ride essentials.

Active Braking Pivot allows our engineers to tune how the suspension reacts to acceleration and braking forces independently. That means you get more confident control when you need it most.

Learn more

This bike doesn’t come with pedals because you'll have a better ride if you choose your own. Explore the pedal guide to find the best pedals for your riding style. Reach for flat pedals for simple versatility or go for clipless MTB pedals if you want control and efficiency.

See the guide

This suspension calculator will help you optimise your suspension settings for your riding weight. Simply follow the steps to find your best set up.

Learn more

Tubeless Ready rims and tyres make it easy to ditch the tubes so you get better traction, fewer flats and less weight. You're ready to roll straight out of the box with the included TLR rim strips, valves and sealant.

Learn more

Bigger is better. The oversized seat tube diameter gives more support and strength for longer travel droppers, and allows for more robust, durable internals that work faster.

International Standard Chain-Guide mounts offer easy chain-guide installation and adjustment.

More robust than pressfit, threaded BBs hold up in nasty conditions and make servicing easier.

Enjoy precise, lightning fast gear changes – even when shifting under load – with Eagle AXS wireless electronic drivetrains. They're water and dust-proof, and the AXS app makes it easy to personalise your settings.

Specs

Frame	OCLV Mountain Carbon, internal storage, tapered head tube, internal guided routing, downtube guard, alloy rocker link, 4-way Mino Link, ABP, Boost148, 120 mm travel
Fork	RockShox Pike Select+, DebonAir spring, Charger 3.1 RC2 damper, tapered steerer, 44 mm offset, Boost110, 15 mm Maxle Stealth, 130 mm travel
Shock	RockShox Deluxe Ultimate RCT, 185 mm x 50 mm
Max compatible fork travel	140 mm

*Wheel front	Size: S Bontrager Line Comp 30, Tubeless Ready, 6-bolt, Boost110, 15 mm thru axle, 27.5"
Size: M, ML, L, XL Bontrager Line Comp 30, Tubeless Ready, 6-bolt, Boost110, 15 mm thru axle, 29"
Size: M, ML, L, XL Bontrager Line Comp 30, Tubeless Ready, 6-bolt, Boost110, 15mm thru axle, 29''
*Wheel rear	Size: S Bontrager Line Comp 30, High Strength 6000 Series Aluminium rim, Tubeless-Ready, Rapid Drive 108, 6-bolt, SRAM XD freehub, Boost148, 12 mm thru axle, 27.5"
Size: S Bontrager Line Comp 30, Tubeless Ready, Rapid Drive 108, 6-bolt, Boost148, 12mm thru axle, 27.5''
Size: M, ML, L, XL Bontrager Line Comp 30, High Strength 6000 Series Aluminium rim, Tubeless-Ready, Rapid Drive 108, 6-bolt, SRAM XD freehub, Boost148, 12 mm thru axle, 29"
Size: M, ML, L, XL Bontrager Line Comp 30, Tubeless Ready, Rapid Drive 108, 6-bolt, Boost148, 12mm thru axle, 29''
Skewer rear	Bontrager Switch thru-axle, removable lever
Spokes	14 g stainless steel, black
*Tyre	Size: S Bontrager Gunnison RSL XT, Tubeless-Ready, triple compound, aramid bead, 120 tpi, 27.5x2.40"
Size: M, ML, L, XL Bontrager Montrose RSL XT, Tubeless-Ready, triple compound, aramid bead, 120 tpi, 29x2.40"
Size: M, ML, L, XL Bontrager Gunnison RSL XT, Tubeless-Ready, triple compound, aramid bead, 120 tpi, 29x2.40"
Tyre part	Bontrager TLR sealant, 180 ml/6 oz
Rim strip	Bontrager TLR
Max tyre size	Frame: 29x2.50", Fork: See manufacturer

Battery	SRAM eTap battery pack (with charger)

Shifter	SRAM AXS POD
Rear derailleur	SRAM GX Eagle AXS, T-Type
Crank	SRAM GX Eagle, T-Type, DUB, 30T, 55 mm chain line, 170 mm length
Bottom bracket	SRAM DUB MTB Wide, 73 m, BSA threaded
Cassette	SRAM Eagle XS-1275, T-Type, 10-52, 12-speed
Chain	SRAM GX Eagle, T-Type, 12-speed
Max. chainring size	1x: 34T, min 30T

Saddle	Verse Short Comp, steel rails, 145 mm width
*Seatpost	Size: S Bontrager Line Dropper, 100mm travel, MaxFlow, internal routing, 34.9 mm, 310mm length
Size: M, ML, L, XL Bontrager Line Dropper, 170 mm travel, MaxFlow, internal routing, 34.9 mm, 450 mm length
*Handlebar/stem (integrated)	Size: S Bontrager RSL Integrated handlebar/stem, OCLV Carbon, 27.5 mm handlebar rise, 820 mm width, 0-degree stem rise, 35 mm stem length
Size: M, ML, L, XL Bontrager RSL Integrated handlebar/stem, OCLV Carbon, 27.5 mm handlebar rise, 820 mm width, 0-degree stem rise, 45mm stem length
Grips	Bontrager XR Trail Elite, nylon lock-on
Brake	SRAM Level Bronze 4-piston hydraulic disc
Brake rotor	SRAM CentreLine, 6-bolt, round-edge, 180 mm
Rotor size	Max brake rotor sizes – Frame: 200 mm, min 180 mm, Fork: see fork manufacturer

Bag	Bontrager BITS Internal Frame Storage Bag

Weight	M - 13.20 kg / 29.11 lbs (with TLR sealant, no tubes)
Weight limit	This bike has a maximum total weight limit (combined weight of bicycle, rider and cargo) of 136 kg (300 lb).

Sizing

How tall are you?

To measure your height, stand up straight, barefoot, with your back, heels, shoulders and head all touching a wall. While looking straight ahead, place a book or straight edge on your head and slowly push it against the wall. Your straight edge should be parallel with the floor. Mark the spot where the bottom of the book is touching the wall. The distance from the marked spot to the floor is your height.

What is your inside leg?

How to measure: Stand barefoot with your back straight and against a wall. Tuck a ruler or something that extends to the floor between your legs. Using both hands, and keeping it level, pull the ruler up into your crotch as if you were sitting on the saddle. Measure the distance from the top edge of the ruler to the ground to find your inside leg measurement. Your inside leg is very important to your final bike size so please measure carefully.

Geometry

Service

Reviews

"More capable & adaptable than ever"

"Increased versatility and broader appeal"

"Enthusiastic and sporty, offering up impressive pedal efficiency with loads of grip."

"Dear lord, this bike is a hoot"

"light, lively and efficient"

More options

Service manual

FAQ

Which Generation?

Make the Top Fuel yours

4-way Mino Link

New internal storage with new BITS bags

Active Braking Pivot

You almost forgot your pedals

Suspension Calculator

Complete Tubeless System

Oversized 34.9mm dropper post

ISCG mounts

Threaded bottom bracket

SRAM Eagle AXS drivetrain

How tall are you?

What is your inside leg?

"More capable & adaptable than ever"

"Increased versatility and broader appeal"

"Enthusiastic and sporty, offering up impressive pedal efficiency with loads of grip."

"Dear lord, this bike is a hoot"

"light, lively and efficient"

More options

Service manual

FAQ

Which Generation?

Product features

Make the Top Fuel yours

4-way Mino Link

New internal storage with new BITS bags

Active Braking Pivot

You almost forgot your pedals

Suspension Calculator

Complete Tubeless System

Oversized 34.9mm dropper post

ISCG mounts

Threaded bottom bracket

SRAM Eagle AXS drivetrain

How tall are you?

What is your inside leg?