Trek set out on an aggressive weight-saving campaign for the latest Superfly 100, and by all accounts its engineering team was largely successful. Even with a not-incredibly-light Shimano Deore XT group and mid-range wheels, our medium-s...
Trek set out on an aggressive weight-saving campaign for the latest Superfly 100, and by all accounts its engineering team was largely successful. Even with a not-incredibly-light Shimano Deore XT group and mid-range wheels, our medium-size Superfly 100 Elite SL test bike weighs just 10.90kg (24.03lb) without pedals. The lack of mass is noticeable on the trail but, unfortunately, so is the lack of stiffness and so-so pedaling performance.Pros: Good high-speed geometry; lively rear suspension performance; light weightCons: Not very efficient; not very stiff; very long wheelbaseRide & handling: Lightweight with good suspension but lacking in efficiencyThe revamped Superfly 100 platform feels right at home on fast and flowy trails with lots of wide open, high speed sections. The long wheelbase and relatively low bottom bracket provide a very stable feel through sweeping corners. And even though it's lost 10mm of movement compared to its predecessor, the remaining 100mm of rear suspension is active and pleasantly progressive, impressively sucking up smaller trail chatter without bottoming out harshly on bigger impacts while maintaining a lively feel throughout. The rear end offers a good amount of pop for leaping out of berms and dips. And, as we've noted in the past, Trek's G2 geometry, with its increased-offset fork crown, goes a long way towards neutralizing both the big feel of 29in wheels and its unusually long wheelbase. Steering feels light and natural without requiring much in the way of excessive rider input, and it's usually only in very tight switchbacks that you notice the Superfly 100 Elite SL's considerable overall length.Like the Giant Anthem X Advanced 29er we tested last year, though, the Superfly 100's chain stays are still a little long at 452mm. Therefore, it's not the most natural bike to manual or wheelie. Carbon fiber seat stays but aluminum chain staysSuch handling traits would generally be no big deal in the Superfly 100's intended context of cross-country racing, where speeds are usually higher and there often aren't as many technical features as in general trail riding or enduro. However, the Superfly also doesn't pedal that efficiently, either.Switching the Fox Float CTD rear shock to its middle Trail setting is a must nearly any time pedaling is required, and we frequently resorted to the firmest Climb position even on short sections of fireroad. We saved the fully open Descend setting for extended downhills only. Otherwise, there's far too much movement and a somewhat dull feel under power, particularly when you're hammering along in the big ring.Nor did we find the Superfly 100 Elite SL's new carbon fiber frame particularly rigid. Front triangle stiffness is admittedly quite good, with the large diameter, nominally round main frame cross-sections and tapered head tube. That's largely squandered out back, though, with an appreciable amount of out-of-plane flex, particularly in high-load situations such as bermed corners or excessively rough sections of trail. Here, instead of the rear wheel tracking precisely behind the front one, we repeatedly noticed the rear loading up – only to spring back when unloaded, which occasionally sent us off-line.One simple test verified our suspicions, too: stand beside the Superfly 100 Elite SL with one hand atop the rear tire and the other on the saddle, push forward on one side while pulling back on the other, and you can see the top of the seat stays moving side to side relative to the seat tube more easily than one would expect from a bike of this caliber. We should note that two BikeRadar testers independently came to identical conclusions on two separate test samples. Naturally, Trek has expressed concern over our findings."We're going to be testing that bike to evaluate stiffness testing," said Trek mountain bike brand manager Travis Ott. "I trust you felt what you experienced. Numerous sessions with pros and test riders haven’t exposed any weakness