bikes mostly had 29-inch wheels and used a swing-link suspension design with a link that hung from the top tube. Trek branded mountain bikes typically had 26-inch wheels and used a rocker-link suspension, where the link is mounted on the seat tube.
The growing popularity of bikes with 29-inch wheels, and other considerations, made it difficult for Trek to keep the brands separate and the company eventually scuttled the Fisher brand and started producing 29ers under the Trek name. The move also allowed the company to choose the most appropriate suspension design for each particular model.
This is illustrated by the new 120mm-travel Fuel EX 29
, which we recently test rode in Sedona, Arizona (our initial impressions are below). Previously, Trek filled the trail 29er category with the 120mm Rumblefish
(first marketed under the Fisher name), which used the swing-link suspension. But that suspension design has limitations, especially as travel increases beyond 100mm, said Dylan Howes, Trek's director of frame and suspension technology. Beyond that threshold, the swing link's shock rate takes on a "hump curve," which creates a plush ride, but with a soft spot in the middle of the stroke—some riders might say it wallows mid-travel.
Although the Fuel EX 29 has 29-inch wheels, it feels not unlike the fast-handling 26-inch version. (Sterling Lorence)
Engineers like Howes can avoid that pitfall, but only by arranging the shock and links in a way that encroaches into the space typically reserved for a water bottle. Trek didn't want to sacrifice that premium real estate, so it evaluated other solutions.
Unlike the swing-link, the rocker-link design used on Trek's 26-inch wheeled bikes (including the 120mm Fuel EX) feels progressive as the bike moves through its travel. So, when it came time to freshen its 120mm 29er, Trek's looked beyond the swing-link Rumblefish (still shown in Trek's line on their site, but we expect it will disappear soon) and stick big wheels into the Fuel EX's rocker-link. Presto: the Fuel EX 29 was born.
What's remarkable about the EX 29 is that it is not much different than an EX 26. Some of the tubes are longer to accommodate the larger wheels, but from the side, they look almost identical. Both bikes also have the same 120mm of travel, similar frame reach per size, and nearly identical shock rates.
The new EX 29 uses Trek’s rocker-link suspension, which was previously reserved for the brand’s 26-inch models. (Sterling Lorence)
Trek expects the EX 29 to be its most popular model and will offer the bike in a range of packages. This leads to an array of frame configurations. There are two grades of aluminum frames available for the five most economical models (one for the EX 5 and 6, and another for the EX 7, 8, and 9). The higher-end Fuel EX 9.7, 9.8 and 9.9 share the same carbon front triangle, but have different rear ends—the 9.7 has aluminum stays, the 9.8 has carbon seatstays and aluminum chainstays, and the 9.9 has a full carbon rear. Trek claims the frames weigh from 5.3 pounds to 3.9 pounds and all models come in six sizes between 15.5 to 23 inches.
Additionally, each frame features a tapered head tube, press-fit bottom bracket, thru-axle-compatible rear dropouts, magnesium rocker link, and a guard on the downtube to protect against rock strikes. The EX 7 through 9.9 have internal cable routing, ISCG 05 chainguide tabs, and internal and external dropper-post routing. The carbon models have a removable front-derailleur mount for 1x drivetrains.
The EX 7 through 9.9 also are equipped with Trek's proprietary, Fox-built DRCV (dual rate control valve) shock with dual air chambers. Trek says DRCV combines the control and small-bump compliance of a small-volume shock with the big-hit plushness of a larger air can.
Trek's ABP (Active Braking Pivot) helps prevent the suspension from stiffening while braking. (Sterling Lorence)
Up front, all models use forks with 51mm offset, instead of the usual 47mm. Trek claims the increased offset improves low-speed handling and makes the bike feel livelier. While Trek made a big push with its DRCV forks recently, the forks aren’t used on the EX29. Trek told us that Fox's newest forks perform almost as well as the DRCV-equipped models, but have fewer parts and cost less.
First ride impressions
We tested the new Fuel EX29 in Sedona, and truthfully, many of the trails we rode are better suited for a bike with more travel such as Trek’s Remedy 29, which we also rode there. But they provided an opportunity to push the Fuel hard, and find its limits.
As I mentioned earlier, the EX29 and EX26 look similar in many ways. That sameness carries over to ride as well. While the 29er version has 120mm of travel, it feels almost like an XC bike—let’s call it XC-plus. Unlike many 120mm 29ers I’ve ridden, this one feels lighter, quicker and faster. In some demanding situations, I noticed some flex and deflection, but that could have come from the Fox 32 fork.
During our test rides, I preferred setting the Fox suspension in Trail mode—the middle of three damping options. That setting created a firmer ride with crisp pedaling that suited the bike’s light and quick handling. When I flipped the shock to Descend mode, the EX felt sensitive and plush, as if it had gained some travel, and the rear end felt like it was stolen from a longer-travel bike. But that created a disconnect for me—the racey front end felt disjointed from the enduro-like rear. Some may like the combination, but I preferred the consistent and nimble feel of the firmer suspension setting. No matter how you ride it, I believe the new EX is superior to the swing-link Rumblefish it replaces.
Here's a basic breakdown of the six Fuel EX 29 models:
Fuel EX 7 29
$2,630, aluminum-alloy frame; Fox 32 Float Evolution CTD fork; Fox Evolution Float CTD DRCV shock; Shimano Deore-level 3x10 drivetrain and brakes; Bontrager Duster tubeless-ready rims; 135mm QR rear axle. Claimed weight: 30.2lb.
Fuel EX 8 29
$2,940, aluminum-alloy frame; Fox 32 Float Evolution CTD fork; Fox Evolution Float CTD DRCV shock; Shimano SLX-level 3x10 drivetrain and brakes; Bontrager Rhythm Elite wheels; 142x12mm rear thru axle. Claimed weight: 28.8lb.
Fuel EX 9 29
$4,200, aluminum-alloy frame; Fox 32 Float Factory CTD fork; Fox Evolution Float CTD DRCV shock; Shimano XT-level 2x10 drivetrain and brakes; Bontrager Rhythm Elite wheels. Claimed weight: 28.2lb.
Fuel EX 9.7 29
$4,200, carbon mainframe with aluminum-alloy rear triangle; Fox 32 Float Evolution CTD fork; Fox Evolution Float CTD DRCV shock; Shimano SLX-level 3x10 drivetrain and brakes; Bontrager Duster tubeless-ready rims. Claimed weight: 28lb.
Fuel EX 9.8 29
$5,250, carbon mainframe with carbon seatstays and aluminum-alloy chainstays; Fox 32 Float Performance CTD fork; Fox Performance Float CTD DRCV shock; Shimano XT-level 2x10 drivetrain and brakes; Bontrager Rhythm Elite wheels. Claimed weight: 26.9lb.
Fuel EC 9.9 29
Full carbon frame, available only through Trek’s Project One custom parts and paint program. Approximately $6,100 to $9,400, depending on configuration. More about this below.
Lower-cost Fuel EX 5 29 ($1,800) and EX 6 29 ($2,100) models are still being developed and Trek has yet to specify the final components. Their frames are simpler (no ISCG tabs for example) to keep the price down.
The highest-end Fuel EX 29 9.9 is only offered through Trek's Project One program. The program allows an individual to customize a bike’s paint and parts from within a range of options.
You start with paint. Four ready-made color options and five customizable schemes are available. Then pick your drivetrain, component and suspension details. Drivetrain options are expansive: XT or XTR from Shimano; X9, X0, XX, and XX1 from SRAM. Wisely, Trek allows you mix Shimano brakes a SRAM drivetrain, or vice versa.
Unlike a true custom program, some of the details, including frame size, saddle width, and rotor size, among others, are determined after a consultation with a local Trek dealer. Trek believes working through dealers ensures customer get a perfectly dialed bike with no errors. (Of course, the shop might also help a customer choose helmets, shoes and other accessories.)
Whether you choose a custom EX 9.9, or a more basic EX 7, you’ll likely find that the bike is a fast, responsive bike, and a nice addition to Trek’s range of 29ers.
Though smooth in spots, most of Sedona’s technical trails pushed the EX 29 to its limits. (Dan Milner)
Not long ago, Trek had two brands in its stable.