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It's right for you if...
You’re looking for a do-it-all full suspension mountain bike that balances efficiency with shred-ability. You want to rip rough descents, fly up climbs, and crush lap after lap.
The tech you get
A lightweight aluminum frame with internal storage, 120mm RockShox SID fork with plush DebonAir spring, 120mm of rear travel with a FOX Performance Float shock, and a Shimano XT drivetrain. Plus, 4-piston brakes for confident descents, Bontrager Line Comp 30 wheels that are already completely tubeless ready, including sealant, and a Bontrager Line Dropper.
The final word
Top Fuel 8 gets you the value of an alloy frame with drivetrain, fork, and brake upgrades that keep up as you progress in speed and skill.
The Walkthrough
favorite_borderWhy you'll love it
- This bike’s killer suspension setup is both efficient and ready to party
- Mino Link lets you make small adjustments to your geometry quickly and easily, even mid-ride
- A sleek internal storage compartment gives you a versatile spot to stow tools and gear
- New, removable Knock Block has a bigger steering angle to keep cables and hoses safe without sacrificing turning radius
MBUK’s Trail Bike of the Year 2022
“It’s easy to look at the bike from afar and assume this is just another downcountry rig... It wasn’t until I’d fired it over some jumps, nosed it down the odd steep chute and slung it through my test loops’ berms that I realised the Top Fuel is, simply put, a bloody brilliant trail bike.”
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"Enduro’s Best Downcountry Bike of 2022"
"Top Fuel 9.9 XX1 AXS earned top honors in Enduro’s round-up of best downcountry rippers, thanks to the bike’s clean look, practical details, and progressive suspension."
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"This is a really, really good bike"
"The Top Fuel is a very capable descender, but its well-proportioned geometry is just half the story. It manages to strike a great balance between grip, tracking, and precision. The whole bike seems to just will you on to hit things faster and with more precision."
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"This thing rips"
"The new Top Fuel is also much more composed on rough and fast descents. Thanks to the longer reach and slacker head angle, the overall wheelbase length has grown by almost 40mm. That’s huge, and it offers a vastly more planted feel at speed. Along with the big tyres and active suspension, this really is a solid little trail bike."
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Features
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.
Quick and in control
120mm of rear travel combined with progressive trail geometry gives you a fast, responsive ride that helps you keep your cool when the trail turns rowdy.
Internal frame storage makes it easy to ditch the pack and still carry your ride essentials.
Guided internal cable routing keeps Top Fuel quiet on the trail and maintenance a breeze.
Will my bike have a curved top tube?
Smaller frames (XS and S) have a curved top tube. This design makes for a lower standover height, which allows shorter riders to straddle the bike more easily. Larger frames (M and up) have a straight top tube because taller riders with longer legs typically don't have the same issues with standover height.
Complete Tubeless System
Tubeless Ready rims and tires make it easy to ditch the tubes so you get better traction, fewer flats, and less weight. You're ready to roll right out of the box with the included TLR rim strips, valves, and sealant.
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Suspension Calculator
This suspension calculator will help you optimize your suspension settings for your riding weight. Simply follow the steps to find your best set up.
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Oversized 34.9mm dropper post
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.
Threaded bottom bracket
More robust than pressfit, threaded BBs hold up in nasty conditions and make servicing easier.
ISCG mounts
International Standard Chain Guide mounts offer easy chain guide installation and adjustment.
Knock Block
Knock Block has your frame's back when things go wrong. It prevents your handlebars from spinning all the way around in a crash, so your hoses won't get yanked, and your controls won't hit the top tube.
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Mino Link adjustable geometry
Fine tune head tube angle by 1/2° and BB height by up to 10mm with the simple turn of a nut. Just flip the link to choose between slack or slacker geometry, without negatively affecting suspension performance. A Trek exclusive.
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Specifications
*spec applies to all sizes unless otherwise noted
| Frame | Alpha Platinum Aluminum, internal storage, tapered head tube, Knock Block 2.0, internal guided routing, downtube guard, magnesium rocker link, Mino Link, ABP, Boost148, 120mm travel |
|---|---|
| Fork | RockShox SID, DebonAir spring, Rush RL damper, lockout, tapered steerer, 44mm offset, Boost110, 15mm Maxle Stealth, 120mm travel |
| Shock | RockShox Deluxe Ulitmate RCT, 185mm x 50mm |
| Max compatible fork travel | 130mm (541mm axle-to-crown) |
| Wheel front | Bontrager Line Comp 30, Tubeless Ready, 6-bolt, Boost110, 15mm thru axle |
|---|---|
| Wheel rear | Bontrager Line Comp 30, Tubeless Ready, Rapid Drive 108, 6-bolt, Boost148, 12mm thru axle |
| Hub front | Bontrager alloy, sealed bearing, alloy axle, 6-bolt, Boost110, 15mm thru axle |
| *Hub rear |
Size:
S, M, M/L, L, XL, XXL Bontrager alloy, sealed bearing, 6-bolt, Rapid Drive 108, Shimano MicroSpline freehub, Boost148, 12mm thru axle |
|
Size:
S, M, M/L, L, XL, XXL Bontrager alloy, sealed bearing, 6-bolt, Shimano MicroSpline freehub, Boost148, 12mm thru axle |
|
| Skewer rear | Bontrager Switch thru axle, removable lever |
| Rim | Bontrager Line Comp 30, Tubeless Ready, 6-bolt, Boost110, 15mm thru axle |
| Tire | Bontrager XR4 Team Issue, Tubeless Ready, Inner Strength sidewalls, aramid bead, 120tpi, 29.x2.40'' |
| Tire part | Bontrager TLR sealant, 6oz |
| Rim strip | Bontrager TLR |
| Max tire size | Frame: 29x2.5" Fork: see manufacturer |
| Shifter | Shimano XT M8100, 12 speed |
|---|---|
| Rear derailleur | Shimano XT M8100, long cage |
| *Crank |
Size:
S, M, M/L, L Shimano Deore M6120, 30T ring, 55mm chainline, 170mm length |
|
Size:
XL, XXL Shimano Deore M6120, 30T ring, 55mm chainline, 175mm length |
|
| Bottom bracket | Shimano SM-BB52, 73mm, threaded external bearing |
| Cassette | Shimano SLX M7100, 10-51, 12 speed |
| Chain | Shimano SLX M7100, 12 speed |
| Max chainring size | Max: 36T (oval - 34T) Min: 28T |
| Saddle | Bontrager Arvada, steel rails, 138mm width |
|---|---|
| *Seatpost |
Size:
S TranzX JD-YSP39, 100mm travel, internal routing, 34.9mm |
|
Size:
M, M/L TranzX JD-YSP39, 150mm travel, internal routing, 34.9mm |
|
|
Size:
L, XL, XXL TranzX JD-YSP39, 170mm travel, internal routing, 34.9mm |
|
| *Handlebar |
Size:
S Bontrager Line, alloy, 35mm, 27.5mm rise, 750mm width |
|
Size:
M, M/L, L, XL, XXL Bontrager Line, alloy, 35mm, 27.5mm rise, 780mm width |
|
| Grips | Bontrager XR Trail Comp, nylon lock-on |
| Stem | Bontrager Elite, 35mm, 0 degree, 45mm length |
| Headset | Knock Block 2.0 Integrated, 72-degree radius (includes infinite-radius chip), sealed cartridge bearing, 1-1/8'' top, 1.5'' bottom |
| Brake | Shimano 4-piston hydraulic disc, M6100 lever, M6120 caliper |
| *Brake rotor |
Size:
S, M, M/L, L, XL, XXL Shimano RT66, 6-bolt, 160mm |
|
Size:
S, M, M/L, L, XL, XXL Shimano RT66, 6-bolt, 180mm |
| Bag | Bontrager BITS Internal Frame Storage Bag |
|---|
| Weight | M - 14.26 kg / 31.44 lbs (with TLR sealant, no tubes) |
|---|---|
| Weight limit | This bike has a maximum total weight limit (combined weight of bicycle, rider, and cargo) of 300 pounds (136 kg). |
Sizing & Tech
The charts below show our recommended sizes based on height, but there are some other factors, like arm and leg length, that determine a great fit. That’s why you’ll see some overlap in our recommendations. Not every rider who’s 5´8˝, for example, will fit on the same size bike. The best way to find your perfect fit is to consult the experts at your local retailer.
All measurements provided in cm unless otherwise noted.
| Frame size number | Frame size letter | Geometry position | Wheel size | A — Seat tube | B — Seat tube angle | Effective seat tube angle | C — Head tube length | D — Head angle | E — Effective top tube | F — Bottom bracket height | G — Bottom bracket drop | H — Chainstay length | I — Offset | J — Trail | K — Wheelbase | L — Standover | M — Frame reach | N — Frame stack |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 15.5 | S | High | 29" | 39.5 | 70.4° | 76.4° | 10.0 | 66.4° | 56.7 | 34.3 | 3.1 | 43.4 | 4.4 | 11.5 | 115.0 | 71.9 | 42.4 | 59.2 |
| 15.5 | S | Low | 29" | 39.5 | 70.0° | 76.0° | 10.0 | 66.0° | 56.8 | 33.8 | 3.6 | 43.5 | 4.4 | 11.8 | 115.1 | 71.5 | 42.0 | 59.5 |
| 17.5 | M | High | 29" | 42.0 | 70.4° | 76.4° | 10.0 | 66.4° | 59.7 | 34.3 | 3.1 | 43.4 | 4.4 | 11.5 | 118.0 | 74.0 | 45.4 | 59.2 |
| 17.5 | M | Low | 29" | 42.0 | 70.0° | 76.0° | 10.0 | 66.0° | 59.8 | 33.8 | 3.6 | 43.5 | 4.4 | 11.8 | 118.1 | 73.5 | 45.0 | 59.5 |
| 18.5 | ML | High | 29" | 43.5 | 70.4° | 76.4° | 10.5 | 66.4° | 61.4 | 34.3 | 3.1 | 43.4 | 4.4 | 11.5 | 119.7 | 74.5 | 46.9 | 59.7 |
| 18.5 | ML | Low | 29" | 43.5 | 70.0° | 76.0° | 10.5 | 66.0° | 61.5 | 33.8 | 3.6 | 43.5 | 4.4 | 11.8 | 119.8 | 74.0 | 46.5 | 60.0 |
| 19.5 | L | High | 29" | 45.0 | 70.4° | 76.4° | 11.0 | 66.4° | 63.0 | 34.3 | 3.1 | 43.4 | 4.4 | 11.5 | 121.4 | 75.0 | 48.4 | 60.1 |
| 19.5 | L | Low | 29" | 45.0 | 70.0° | 76.0° | 11.0 | 66.0° | 63.1 | 33.8 | 3.6 | 43.5 | 4.4 | 11.8 | 121.5 | 74.5 | 48.0 | 60.5 |
| 21.5 | XL | High | 29" | 50.0 | 70.4° | 76.4° | 12.5 | 66.4° | 65.3 | 34.3 | 3.1 | 43.4 | 4.4 | 11.5 | 124.0 | 76.0 | 50.4 | 61.5 |
| 21.5 | XL | Low | 29" | 50.0 | 70.0° | 76.0° | 12.5 | 66.0° | 65.4 | 33.8 | 3.6 | 43.5 | 4.4 | 11.8 | 124.1 | 75.5 | 50.0 | 61.8 |
| 23.0 | XXL | High | 29" | 54.0 | 70.4° | 76.4° | 13.5 | 66.4° | 67.5 | 34.3 | 3.0 | 43.4 | 4.4 | 11.5 | 126.5 | 77.0 | 52.4 | 62.4 |
| 23.0 | XXL | Low | 29" | 54.0 | 70.0° | 76.0° | 13.5 | 66.0° | 67.6 | 33.8 | 3.6 | 43.5 | 4.4 | 11.8 | 126.5 | 76.5 | 52.0 | 62.7 |