The 2014 Trek Superfly FS 8 is affordable, has oversized wheels and is quite light for a full suspension mountain bike. The 29 inch wheels are a real advantage in the punishing terrain where I ride. My 15.5 sized Trek Superfly weighs 27.8 lbs with pedals. It is classified as a cross country race bike. It is that in spades plus a lot more. Let me explain.
To be honest, I was tempted to purchase Trek’s rigid cross country carbon fiber racer (the Superfly), but I wanted something that I could confidently ride over difficult terrain. After all, isn’t that what the bigger wheel size is all about?
Also, I didn’t want the burden of pedaling a heavyweight all mountain bike with five or six inches of suspension travel. The trails where I ride near my home do not require that much suspension. The Superfly FS 8 seemed like a pretty good compromise between light weight, cost and overall good confident trail manners.
Like most modern full suspension bikes with the bigger wheels, the Superfly looks a little awkward with its oversized, elongated out of round tubes, but as soon as I got on and started pedaling, the bike disappeared underneath me. It felt like an extension of my body.To be honest, it does have a lovely understated paint job. The green highlights on the frame accentuates the green pattern on the rims.
The main point of writing this is to describe the bike and how it feels on the trail. To see all the specifications and high tech details go to: http://www.trekbikes.com/us/en/bikes/mountain/cross_country/superfly_fs/superfly_fs_8/#
The G2 geometry is a product of Gary Fisher’s genius. He had been playing around with 29 inch mountain bike wheels before the bigger wheel size became popular. This bike is a result of his design virtuosity and one ride is enough to make anyone a believer. Between the fairly steep head angle and slightly increased fork offset it handles like a dream. It seems to anticipate your every move and it is rock solid at speed. It puts some longer travel bikes to shame.
The over-sized through axles and well thought out bracing make it a stable downhill handler. It is a thoroughbred race bike. As such it demands that the rider pay attention and not lose focus, especially as the rider gains confidence and takes the bike to the ragged edge. Racing over scary, steep terrain at speed is this bike’s forte although it is classified as a cross country bike.
Because it is a less expensive version of the Superfly full suspension bike, the frame is made out of aluminum not the sexier carbon fiber. Like most premium aluminum frames produced these days, Trek uses its own blend of high quality aluminum. It is cold extruded and hydroformed for maximum strength and stiffness with the least amount of weight. The process does not use heat to pour molten aluminum into a tubular mold. Instead the metal is squeezed into a fairly sophisticated high tech Matrix.
The Superfly FS positions the rider in a moderately aggressive stance over the front end. The chain stays do not feel unreasonably long and it manuals and flicks around with ease. It is fun to grab some air and then throw it sideways like a BMX bike
It only has about four inches of suspension travel with a single carbon link and no rocker arm. With the bigger wheels you would never guess that it has less than five inches of travel. This type of suspension is not as tunable as a bike with a rocker link, but it is lighter and works well with the bigger wheels on bikes with limited travel. The suspension front and rear is reinforced by multiple anchor points and well thought out bracing to give the bike maximum rigidity for either pedaling uphill or bombing downhill.
It has an XT Shadow rear derailleur that works a like a charm even when up-shifting in gnarly conditions. The rest of the components are SLX and Bontrager. The SLX disc brakes are a decent brake-set. They are progressive and not overly touchy. The drive train is smooth and reasonably quiet although an upgrade to a higher quality chain and rear cog-set is recommended when it is time for replacement. Good stuff…
The Trek is stiff and maneuverable almost like a modern aluminum road bike. The over-sized headset and wide, press fit bottom bracket add to a stiff unyielding feel whether pedaling uphill or on screaming descents. It can hit high speed ruts, roots and rocks without losing its composure and then pedal uphill with hardly a hint of pedal induced bob.
The chain stay pivot is placed about even with the big ring in the front. It has a two ring crank-set and it works fine in both the big and small ring. In short, the suspension seems immune to pedal pressure especially when you stay seated and spin.
The back end of the bike features Trek’s ABP (Active Braking Pivot) concept design, with the suspension pivots rotating around the outside of the rear axle as the shock moves up and down through its travel. The floating pivots are so cleanly integrated that it looks as if the rear end were one solid unit.
It does result in an active ride whether you are braking really hard on steep, rocky, root infested downhill trails or pedaling up over rough, tricky terrain. By active ride, I mean that the suspension is impervious to the forces of braking or pedaling. Thus you get better suspension action whether pedaling up hill or braking on the down hills..
It is a fiend for speed and urges its rider to shift up through the gears and go faster on almost any grade. The super fast rolling Bontrager XR1 Expert tires and moderately light (for the price) Bontrager Mustang rims help it get up to speed. Once up to speed it maintains momentum with its over-sized wheels and aggressive geometry.
Initially it feels like that the smaller of the two rings in the front does not give enough of a mechanical advantage (24 teeth), but as its rider gets used to the Superfly FS and with a little bit of the badger mentality, it is up and over even the steepest climbs. It feels fast almost like a high tech road bike specially designed for the trails.
The bigger wheels provide more traction whether ascending or descending. Braking on steep downhill pitches is much better with the bigger wheels. The main advantage, of course, is the fact that they roll over obstacles much easier than conventional 26 inch mountain bike wheels. In addition, the wheels stick better in high speed turns.
The suspension is Fox CTD front and rear. CTD gives you three suspension adjustment options: Climb, Trail, or Descend. However, the astute rider will use these settings in a variety of circumstances beyond the normal climb, trail and descend situations. Trail is a compromise between stiff (Climb) and more yielding (Descend) and can be used most of the time. However, just leaving it in one position ignores some of the huge advantages of this design. It is much better and more adaptable than the old pro-pedal system.
Rough steep downhill sections can be conquered with the suspension set on Descend front and rear. This bike holds momentum even while dodging obstacles like trees and big rock outcroppings. It turns and maneuvers with ease and seems to float over obstacles that would unhinge even six inches of suspension on a traditional 26 inch wheel mountain bike. It is not scary at speed. The geometry is a magical combination of agility and high speed stability, inspiring the rider to seek new lines.
The Superfly finds lines that most riders would never imagine possible. The rider can follow its lead and thread together deviations off the main trail up and down the most gnarly sections. I cannot begin to describe how much fun it is to ride even with the original fast rolling rather narrow tires.
The Climb mode on the suspension stiffens up the bike and is meant to reduce pedal bob when climbing. However, if you want to jump or bunny-hop the bike you can set it on the Climb mode. It doesn’t seem to move at all when you preload and release over a jump thus giving you really good air. Then the suspension uses up every inch of travel with a bottomless feeling when you land. You can jump pretty well in the Trail setting but the firm setting is better so long as the lead up is not too rough. It is not a downhill bike and so you have to be realistic and not do huge gaps.
The bike gets some getting used to. Rough, steep uphill ledges can be conquered with a little bit of momentum with the suspension set in the Descend setting front and rear. It goes against logic to pedal up steep rough pitches in the Descend mode, but until you try it you won’t know what you are missing. In the Descend setting the suspension has more give for hopping over rocks and roots. Momentum is this bike’s friend and once you are up to speed it floats like a butterfly. You won’t believe the steep rocky ledges that you can pedal over. The big wheels and geometry really help with traction.
Sometimes it pays to keep the bike in the Descend mode even when the trail is not that steep or scary and where you can dodge around the worst obstacles. The other day I was descending a moderately rough trail where the Trail setting would have sufficed. Luckily I was in the Descend mode when a group of hikers caused me to slow down and take a detour that was a lot steeper and rougher than I had originally anticipated. The bike stayed in control as I braked over huge roots and jagged ruts on a vertical pitch that would have upset most 26 inch wheeled bikes and might have caused grievous bodily harm had I not been riding the 29er. Experiences like that gave me incredible confidence in the bike.
After building up my trust in the bike’s capabilities, I used the quick steering to get myself into a situation where I could have gotten into trouble coming back down. There is a section of trial where you can pedal hard in a high gear to build up momentum and then swing off at right angle while still maintaining speed. The trick is to pedal up and over a twenty foot rutted wall without unclipping from the pedals at the top, then float around a tree in one coordinated motion (or not so coordinated motion), and then swing back down the other side over loose dirt and a tangled layer of roots. It takes a little bit of practice, a lot of confidence and some courage to turn back down the steep gnarly slope.
The Bontrager XR1 Expert tires are light and smooth rolling but lack grip on less than perfect surfaces. When they wear out I will replace them with something slightly more heavy duty especially in the front for maximum braking and for traction going around corners. I was a little disappointed with limited clearance issues for really big tires.
It doesn’t have a bottom bracket protector and so you have to be careful lifting the front end over really big rocks so as to not smash the big ring on the crankset. The other major problem is that the water bottle cage is too close to the rear suspension adjuster and taking the water bottle out of the cage while riding could damage the lever. I recommend using a camel back and leaving the water bottle cage off the bike.
Otherwise I love this bike and I would recommend it to anyone whether they race or not so long as the trails where they ride on are not too crazy.