Review: New Trek Top Fuel 9.8 — A super progressive marathon / XC shredder

The Top Fuel has received a complete overhaul for 2020. The changes are in line with the technically demanding landscape of many marathon / XC courses and Down-country riding.

Trek Top Fuel 9.8 review for Bike Network by Myles Kelsey and Gary Perkin.
The 115mm travel and aggressive geometry pits this bike as a capable marathon, cross-country or down-country bike.


  • Frame: 115mm travel, OCLV Mountain Carbon main frame & stays, tapered head tube, Knock Block, Control Freak internal routing, Carbon Armor, magnesium rocker link, Mino Link, ABP, Boost148
  • Fork: Fox Performance 34 Step-Cast, Float EVOL air spring, GRIP 2-position damper, TwistLoc remote, tapered steerer, 44mm offset, Boost110, 15mm Kabolt axle, 120mm travel
  • Shock: Fox Performance Float, 2-position DPS damper, TwistLoc remote, tuned by Trek Suspension Lab, 190x45mm
  • Wheels: Bontrager Kovee Elite 30 carbon, Tubeless Ready, 54pt Rapid Drive, Boost110 front, Boost148 rear
  • Tires: Bontrager XR3 Team Issue, Tubeless Ready, Inner Strength sidewall, aramid bead, 120tpi, 29×2.40″
  • Rear derailleur: SRAM GX Eagle
  • Cranks: Truvativ Descendant 7k Eagle DUB, 32T alloy ring, Boost
  • Cassette: SRAM XG-1275 Eagle, 10-50, 12 speed
  • Saddle: Bontrager Montrose Elite, titanium rails
  • Seatpost: Bontrager Line Elite 170mm Dropper, internal routing, 31.6mm
  • Bars: Bontrager Line Pro, OCLV Carbon, 35mm, 15mm rise, 720mm width
  • Stem: Bontrager Kovee Pro, 35mm, Knock Block, Blendr compatible, 13 degree, 70mm
  • Brakes: Shimano SLX M7000 hydraulic disc, 180mm front rotor, 160mm rear rotor
  • RRP: R89 999
  • Weight: 11.84kgs


Buying the correct size bike is absolutely crucial and since this platform is a complete rebuild based around slightly longer reach and much shorter stems you may very well need to jump up a frame size from your previous bike to get the full benefit of the new platform. Don’t assume you will be the same size as your previous bike. Most of the riders we spoke to, including former professional racers, said they felt more comfortable on the new Top Fuel when they jumped up a size. Chat to your retailer about this or you are welcome to send us any questions.


Why has the Full Floater link been discontinued? The Full Floater link improved small bump compliance but shock technology has improved dramatically and the high volume shocks with lower leverage ratios now do a very good job of smoothing out the smaller hits. Removing the Full Floater system allowed Trek to improve the efficiency of the bike under power and keep the buttery smooth suspension performance.

Why has the G2 geometry been discontinued? G2 was essentially a longer fork offset which was very much needed 10 years ago when bikes had small reach numbers, long stems and steep head angles. In fact I remember test riding one of the G2 equipped Trek 29ers (circa: 2006) in Tokai and the bike was tough to handle on the singletrack – so much so that I cut the ride short. Thankfully bikes are now longer (Reach) and slacker which means we can do away with the huge fork offset numbers of old. Tucking the front wheel a few millimeters back dramatically improves handling and ride characteristics. Shorter offset is not marketing hype, when coupled with the right geometry it simply makes the bike easier to ride. As a result the G2 geometry is no longer needed and Trek has quite rightly phased it out.

Trek Top Fuel 9.8 review for Bike Network by Myles Kelsey and Gary Perkin.
In a sport where we constantly strive for marginal tech gains the move to shorter fork offsets (when coupled with modern geometry) is a very tangible gain on the trail.


At 71kg’s and 1.75m I tested a size large and settled on the following settings:

  • Fork: 81 psi which gave 21% sag
  • Fork rebound: 5 clicks from closed
  • Shock: 182psi which gave 22% sag
  • Shock rebound: 5 clicks from closed
  • Front tire pressure: 18psi
  • Rear tire pressure: 25psi


Climbing: The Top Fuel is built to race marathons and XC, so it’s no surprise that it makes light work of ascending. The longer reach incorporated into the revised geometry provides ample room to sit comfortably into a power climbing position without being cramped. When standing there is ample room to shift body weight to optimize traction and power. The Twistloc remote which opens or closes the front and rear suspension together does clutter up the cockpit a little by virtue of the two extra cables but is a must for racing. The closed setting is not a full or total lockout on the fork — there is some small ‘give’ on big hits. The shock locks out completely though, which means you are pretty much climbing a hardtail rocket ship. In the open setting, the bikes suspension tracks well up loose techy terrain. You really can sit and stomp up rough terrain without spinning out. The small center knobs and big volume Bontrager XR3 tires assist with rolling speed and provide decent bite for climbing too. The Twistloc remote is the big climbing enabler — the Top Fuel is a climbing weapon.

Trek Top Fuel 9.8 review for Bike Network by Myles Kelsey and Gary Perkin.
With fast-rolling rubber, suspension lockout and a bigger reach number the Top Fuel is an incredible climber.

Cornering The longer reach, shorter stem and shortened fork offset mean the cornering feel of the bike is very different at first. Different in that it kind of arcs into the turn naturally without needing any coaxing like some 29er’s do. In fact, the bike turns as well as those 26er’s from years back and carrying speed through flowy turns, flicking the bike through tight turns or setting up and nailing switchbacks is easier on the new Top Fuel. The slightly beefed up XR3 edge knob offers great support and performance when the bike is leaned over. Cornering performance is excellent. It’s hard to believe that a Marathon or XC bike can turn so well.

Descending The big benefit of a 67.5degree head angle for marathon riders is the calm and composed descending characteristic which allows riders to recover on the downhills rather than white knuckle down the race track wasting energy hanging onto an untamed rig. To be accurate, it’s more than just the head angle which makes the bike a great descender — it’s the sum of the entire bike — the geometry, the sizing, and the build kit. The longer reach number combined with the shorter stem increases control tantamount. A 120/115mm travel bike with a 170mm dropper post will knock bucket loads of time off of any riders descending — and add safety. The ABP rear pivot is one of the best suspension systems on the market, it keeps the rear suspension fully active under braking (ie: working properly) by isolating the braking forces away from the shock. The ABP contribution to bike stability and rider control when pinned is tangible. You can charge harder and brake later, in the rough and the Top Fuel maintains composure, traction, with good dynamic geometry.

Trek Top Fuel 9.8 review for Bike Network by Myles Kelsey and Gary Perkin.
It’s more than just the head angle which improves handling — it’s the sum of the entire bike — the geometry, the sizing, and the build kit.

Technical ability “Wow. Really?” – that’s what I was thinking — this bike is something special. Trek have nailed it here, the Top Fuel holds off camber lines well, tracks or steers true through rough sections of trail and is ready for the roughest XC and marathon lines. Jumps, drops and any technical challenge is not a problem. The marginally higher BB works well with the increase in rear wheel travel keeping the dynamic ride height on point so pedaling up rock gardens or other obstacles is no issue.

Is it easy to ride though? You betchya. It’s a marathon race bike with trail bike DNA which means you will nail lines which you previously classified as out of your skillset. I think the real thing about this bike is not the fact that it handles the trail so well, it’s the fact that every rider will carry more speed through technical terrain, corners, and descents making up time on competitors. Granted the extra travel might not be every rider’s cup of tea or suit every single race track out there — but the bike is easier to ride than steep head angled 100mm bikes are.



In terms of technical capability, hard-charging racers will not be left wanting with the Top Fuel, except perhaps on silky smooth race tracks. The new Top Fuel is not only capable of winning the Cape Epic but is perhaps the smartest platform for such a race. It’s very fast, a lot of fun and a real shredder.

Trek Top Fuel 9.8 review for Bike Network by Myles Kelsey and Gary Perkin.

| IMAGES: Gary Perkin |

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