Review: TREK Top Fuel 9.9 XX1 AXS | The stage race specialist & singletrack crusher

The range-topping version of Trek’s new-for-2020 Top Fuel marathon bike is simply a rocket on the trails.

With a plethora of design changes to improve efficiencies during long days in the saddle and a racey all-carbon build, this over-the-counter Super Bike might prove to be the epitome of new-school marathon rigs.

Review Trek Top Fuel Mountain Bike
TREK Top Fuel 9.9 XX1 AXS | R149 999 | 120/115mm | 11.4kg

THE BUILD

With this unapologetically high-end 9.9 model, you are getting the complete race package with all the bells and whistles. SRAM’s chic oil-slick finish chain/cassette combo, a 12-speed AXS wireless electronic shifting setup and carbon XX1 crankset to boot. The grip mounted TwistLoc dual remote lockout system simultaneously locks out the front and rear suspension to optimize efficiency on smooth surfaces. The RockShox Deluxe Ultimate shock delivers coil-like small bump performance and has a neat internal token system to tweak the air volume chamber to customize the ride feel. The Bontrager Kovee wheels are a light-weight, 28 hole, direct-pull, bladed-spoke wheelset with a 30mm inner width to improve grip. The DebonAir equipped 120mm Pike Ultimate is a buttery smooth and quick-handling short offset fork. The other singletrack enablers within the build kit are the long (170mm) AXS Reverb dropper post, robust Bontrager XR3 tyres in a 2.4″ width and a larger front rotor.

  • Bontrgarer Arvada seat
  • SRAM Level Ultimate brakes with carbon levers
  • Top tier carbon chassis
Review Trek Top Fuel Mountain Bike
The heart of the AXS electronic wireless shifting system sits inside this mech which also features a shorter cage for clearance, carbon and Titanium bits and bobs with a neat ‘overload clutch’ which allows the mech to absorb impacts from rock strikes and the like. Mountain biking doesn’t get much more bling than the oil-slick / rainbow colorway on this SRAM chain and cassette.
  • RockShox TwistLoc suspension lockout.
  • The RockShox Deluxe Ultimate shock features a token adjust air chamber to customize progressivity.
  • RockShox Pike Ultimate short offset 120mm fork.
The grip mounted TwistLoc dual remote lockout system simultaneously locks out the front and rear suspension to optimize efficiency on smooth surfaces.
  • Direct-pull, bladed-spoke wheelset by Bontrager.
  • The Bontrager Kovee Pro 30 carbon wheels feature a wider inner diamteter rim which improves grip.

BUILD DETAILS

FRAME| Top Fuel 9.9 OCLV Carbon main frame and stays, Magnesium rocker, Mino Link, ABP, 115mm travel 
FORK| RockShox Pike Ultimate, DebonAir spring, Charger 2 RC 2 damper, 42mm offset and 120mm travel
SHOCK| RockShox Deluxe Ultimate, Bontrager DropLock remote
BARS| Bontrager Line Pro, OCLV Carbon, 15mm rise, 750mm width
STEM| Bontrager Kovee Pro, 35mm clamp, 70mm length, 13-degree
LOCKOUT| RockShox TwistLoc 
SEAT| Bontrager Arvada
SEATPOST| RockShox Reverb AXS, 170mm travel, wireless 
WHEELS| Bontrager Kovee Pro 30 carbon, 108T, 28h, wide internal, direct pull bladed spokes 
TYRES| Bontrager XR3 Team Issue, 120Tpi, 29 x 2.4″
CASSETTE| SRAM Eagle, 10-50, 12 speed
MECH| SRAM XX1 Eagle AXS
SHIFTER| SRAM Eagle AXS wireless
CRANKS| SRAM XX1 Eagle AXS, DUB, 32T, 175mm
CHAIN| SRAM XX1 Eagle  
BRAKES| SRAM Level Ultimate, carbon levers, 180mm / 160mm rotors
WEIGHT| 11.4kg (with sealant, no pedals)
RRP| R149 999
  • The size Large frame runs a long (170mm) Reverb AXS dropper.
  • The AXS Reverb controller means no hoses or wires clutter up the cockpit.
  • The XR3 is a 2.4″ tyre with a bigger edge.
  • Fast-rolling center tread pattern.
The XR3 features reinforced sidewalls for stability and protection with the added bonus of being able to run softer pressures for more grip and compliance. | *Click to enlarge |

GEOMETRY

  • Seat tube angle options are 75.5° or 75°
  • Head angle options are 68° or 67.5°

Thankfully, the traditional short reach and long stem marathon bikes with their sketchy handling characteristics, are slowly but surely becoming something of the past. Whilst Trek is not the very first brand to revise their marathon racing geometry to suit higher speeds, this new Top Fuel is certainly doing its part to redefine the marathon genre. Perhaps a handful of traditionalists might view the 67.5° head tube angle (68° in high setting) as being on the slack side, but in my opinion, it is very much the space that will become the new norm for marathon race bikes.

IN THE LOW SETTING

 SMALLMEDIUMM/LLARGEX-LARGEXX-LARGE
REACH405440456470487510
STACK594594594603612622
STANDOVER725730735745765780
HEAD TUBE ANGLE67.5°67.5°67.5°67.5°67.5°67.5°
SEAT TUBE ANGLE 75.0°75.0°75.0°75.0°75.0°75.0°
HEAD TUBE LENGTH909090100110120
SEAT TUBE LENGTH394419445470521570
WHEELBASE111711521168118612071234
CHAINSTAY435435435435435435
BB HEIGHT337337337337337337
Review Trek Top Fuel Mountain Bike
Throughout the size curves, the Top Fuel is designed around longer reach numbers with shorter stems to improve stability and handling. This model runs a 13-degree stem which accommodates the racers that prefer a super slammed front end.

WHY SHOULD A MARATHON BIKE BE DIFFERENT TO A LAP RACING BIKE?

…. because the inherent nature of marathon or endurance racing is that a lot of the course is ridden blind. This means you are often unaware of what awaits you on the other side of a natural fade-away, drop-off or switchback as you likely have not ridden the course before. There could be a plethora of sharp rocks, loose surfaces, tree trunks or steep roll-offs waiting to end your race. Additionally, marathon racing puts a lot more strain and fatigue into your system because you are out there for hours and hours, getting bounced all over the place. The answer lies firstly in a bike with calmer geometry so you don’t get chucked over the bars when you encounter the unexpected. Secondly, having slightly more suspension will help reduce the build-up of fatigue from the constant vibration and pounding your body endures.

  • Marathon racers are usually racing ‘blind’ – on unknown tracks.
  • Long days in the saddle send a lot of fatigue inducing vibrations into your body.

In contrast, cross country lap racers – like the Olympic Games, World Cup, National, Provincial or School League type events – are not racing blind. They have the opportunity to walk, pre-ride and study every inch of the racetrack prior to competition. They know where all the ‘snipers’ are. By the time the race is underway, they have calculated their line choice, approach speed and tactic for every single technical section. Basically, because they are highly skilled, know every inch of the track and are only racing for around 90 minutes, they generally opt for slightly shorter travel bikes with ‘sensitive’ geometry.

SUSPENSION LAYOUT

The Top Fuel is essentially a rocker link driven, single-pivot suspension layout which uses the split pivot (ABP) system. Moving away from the old Full-Floater system (a linkage which connected the chainstay to the lower shock mount) has improved the weight and stiffness of the chassis. Moving the main pivot a tiny bit forward on this bike has improved the small bump compliance, which, reduces rider fatigue on long days out.

  • Trek’s ABP (split pivot) design has the stays pivoting on the rear axle.
  • The magnesium rocker link scrubs off some grammage.
  • JONKERSHOEK, STELLENBOSCH - riding the Trek Top Fuel in Jonkershoek with Myles Kelsey for Bicycle Network. Photo by Gary Perkin
    The main pivot sits a little further forward and the shock mounts directly onto the downtube.

RIDE IMPRESSIONS

Review Trek Top Fuel Mountain Bike
I have easily done over 15 hours of riding on this bike on trails that regularly see marathon events whiz by. On every ride in Jonkershoek, Table Mountain, Hoogekraal and Tokai there are two standout traits about the Top Fuel which are really impressive: it is comfortable and nails virtually any kind of singletrack.
Review Trek Top Fuel Mountain Bike
I do like to twist some throttle on the downs and so chose not to slam the stem into the lowest position. Nevertheless, the climbing position is efficient and with the suspension open (and rebound correctly set) the bike climbs with composure.
Review Trek Top Fuel Mountain Bike
The Top Fuel makes light work of any switchback. Point and shoot.
  • Set up for the turn
  • Sight the exit
  • Get off the brakes
  • Rail it
The bigger dropper post enables you to shift all your weight to the outside pedal forcing the tyres to bite in as you carry speed through the turn. This bike is really quick through all corners.
Review Trek Top Fuel Mountain Bike
The biggest surprise is how the bike slices and dices a path through gnarly terrain without flinching or chucking you out the front door.
Review Trek Top Fuel Mountain Bike
Twist that lockout closed and stomp it like a hardtail and the Top Fuel is ready to gallop. I cannot say enough about the precise, reliable and quiet shifting of the XX1 AXS system by SRAM. Dammit, it is exceptional.
Conversely, open the suspension, slam the dropper and forget about chicken lines.
Review Trek Top Fuel Mountain Bike
The Top Fuel is one of those rare bikes that makes everything easier. It has a magic-carpet feel to the suspension which helps maintain grip and momentum through any awkward bits. It is a pleasurable and very fast ride.

IF YOU BUY IT

The rear shock has an air volume chamber which accommodates up to three tokens. The bike is sold with two tokens in the shock, which is an average setup suitable for most conditions. If you are after a firmer ride in the open setting, ask your bike store to fit the third token, readjust your sag setting, then rebound and see how it rolls. This air volume chamber is a fantastic feature and you are doing yourself and injustice if you do not experiment with it to find the perfect setup. I also found the bike rides a little swifter with a couple of extra clicks of rebound – so that’s over and above where you would usually ride your rebound.

For smoother marathon tracks – like at KAPSani2c – you can definitely look at running a Bontrager XR1 or XR2 tyre on the front and rear. I would recommend adding silicone slip-on grips to the purchase basket and whatever you do do not take the dropper post off! It’s an enabler, you are far faster and safer with it, it is going to prevent a crash, perhaps save a collarbone and once you are used to it you will wonder how you ever rode without one. Lastly, find a good wrench who will know how to shrink wrap the cables to clean up the cockpit.

THE TECH & MARATHON SETUP TIPS

TAKEOUT

I think everyone agrees that finding the absolute perfect marathon bike for South Africa, is a case of horses-for-courses. If we look to the professionals, it is interesting that despite having the brawn and skills to be fast on shorter travel XCO type bikes, some of them are racing marathons and stage races on bikes that have more than 100mm. You are welcome to disagree with me, but I believe that about 85% of the field at most South African marathon or multi-day events would be faster, safer and have a better experience on a machine that is forgiving, compliant and efficient. The Top Fuel is such a bike. It is a rocket in the singletrack. It is comfortable on long rides. In this top of the line AXS build, it is most certainly a Super Bike equipped to handle any marathon or stage race.

Review Trek Top Fuel Mountain Bike
See you on the trails! Peace.

| IMAGES: Gary Perkin | LOCATION: Jonkershoek, Stellenbosch |

| MORE: trekbikes.com |

SHARE

WhatsApp LinkedIn Pinterest

TAGS