First Impression: 2016 Trek Top Fuel 9.9 SL

Trek discontinued its 26-inch wheeled Top Fuel cross-country line a few years back in favor of re-branding Gary Fisher’s successful 29er Superfly. Now, as the Superfly grows long in the tooth the Top Fuel is reborn in 2016 and it’s as modern and high-tech as a cross-country bike can be.


Like the longer travel Fuel EX, the 100 mm travel Top Fuel uses an EVO rocker link and Full Floater suspension design, which attaches the shock to two moving points. It also has Active Braking Pivot and the geometry adjusting Mono Link nuts that connect the seatstay to the EVO link. This changes head tube angle by half degree and raises or lower the bottom bracket by 8 mm, going from a 70-degree head angle and 12.9 inch bottom bracket in low to 70.9-degress and 13.4-inches in high. This brings to the short travel bike the technology Trek has been using for its long travel bikes, a design that has become one of the best available.


The Top Fuel also has Boost 148/110 hub spacing, Smart Wheel Size and Control Freak cable management. Boost, which was developed in part by Trek last year for its long travel bikes, creates a better and stronger 29-inch wheel. Boost also provides more tire clearance and gave Trek the opportunity to shorten the chainstays by 17 mm compared to the Superfly. At 148 mm, which is as wide as you can go without affecting Q factor, width is maximized without making the bike wider at the bottom bracket. By going 110 mm on the fork the front end is equaled to the rear in terms of strength, stability and the ability to run a bigger tire.

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Trek believes that for cross-country applications a 29er wheel is absolutely the fastest so you won’t be seeing multiple options, it’s 29 only except for the smallest frame size. Smart Wheel Sizing dictates that for this small of the frame 27.5 is the answer to keep the bike fitting right, lower the front end and achieve no wheel overlap.

Believe it or not, with all the various options there are exactly 54 different ways to route cables. To make sure any and all work Trek developed a very flexible system called Control Freak cable management that works with any combination of cables and electronic wires, including internally routed dropper posts.


The $9,450 Top Fuel 9.9 SL we’re currently testing, as you’d expect, has a complete package of top shelf parts including cable Shimano XTR, a Race Face Next carbon crank and single narrow/wide chainring, carbon DT Swiss XMC 1200 wheels, RockShox RS-1 fork with 51 mm G2 offset and some of the lightest Bontrager bits ever made resulting in a weight of a mere 21.3 pounds without pedals. Trek claims a medium frame with shock and all hardware weighs only 4.3 pounds.

For 2016 there are four standard Top Fuel models and one women’s model, plus a frameset:

  • Top Fuel 9.9 SL: full carbon with Rockshox RS-1 fork, Monarch XX shock and carbon wheels: $9,450.
  • Top Fuel 9.8 SL: full carbon with Rockshox SID fork, Monarch XX shock and DT Swiss wheels: $5,250.
  • Top Fuel 9: aluminum frame with Rockshox SID fork, Monarch XX shock and Bontrager wheels: $4,200
  • Top Fuel 8: aluminum frame with Fox Float 32 fork, Fox Float shock and Bontrager wheels: $2,730.
  • Top Fuel 8 Women’s: aluminum frame with Fox Float 32 fork, Fox Float shock and Bontrager wheels: $2,730.
  • Top Fuel SL C frameset with Fox Factory EVOL shock: $3,470.

After a few rides so far the Top Fuel is proving to be an extremely capable cross-country racer as well as a do it all endurance machine within the realm of 100 mm travel. It’s fast, it’s light and it handles like a dream. Look for the full review in Issue #187 after we put a whole lot more miles on it.