Trek Superfly 20 Initial Review – Cool Kit for the Kiddies or Dad Reliving Childhood Dreams?

You remember it don’t you? It was a defining moment, for some of you it was THE defining moment. It changed everything.  Since then you have spent thousands of dollars on kit, yet one piece of kit was the ultimate game changer. You spent thousands of dollars in gas and day passes and for great rides, yet there was one ride changed everything. No mountain biking dollars have ever been better spent than those that bought your first real mountain bike. No ride has ever matched that first real ride.  This past week my son had that moment.

Introducing the newest steed in our collection: The Trek Superfly 20.  Read below to the break to see  my initial impressions


Before reviewing I’d like to give a shout out to Bikeworks in Sylvania Ohio. They beat all the online prices by coming in well under Trek’s MSRP of $419.99. I did not mention online shopping or bicker about price they simply named a good price and ordered the bike for me. Nothing gives you that warm fuzzy “I’m not getting screwed feeling” than a dealer who beats all prices without you having to exert any pressure on them. I’m not going to publish the purchase price but check with your LBS before you go to the online retailer for any complete bike purchase.  (Side note: Trek Bikes must be purchased in a shop, all online retailers will require you to pick the bike up from their location.)

First Impression

First impression of the bike was a little surreal. In northwest Ohio higher end children’s mountain bikes are a low demand item and not typically a part of the showroom stock. I knew how the bike was spec’d before I ordered but when I saw an oversized headtube, oversized bars, beautiful welds, burly looking little frame, legitimate wheels and tires all under 20lbs I was taken by surprise. The local mechanics were beaming about it too.  We see plenty of top end adult mountain bikes around here and have grown accustomed to walking right past them, but the shop mechanics and shoppers alike were shocked by this little bike. Again we are in Ohio where the only nice bikes kids usually ride are BMX. A 20″ bike that can legitimately be called a mountain bike is an anomaly here in the plains. First impression was a win.
(EDIT: I screwed up weighing and originally stated the weight at 17.2 lbs, the true weight is 19.2 still significantly under the competition)


The frame is an “Alpha” aluminum frame which mimics Trek’s adult Superfly line. The welds look quality and everything looks burly. The geometry is specific to children with a low stand over height.  My six year old is average size for his age and has ample clearance. The bike is low enough for him to get on and seems long enough to allow for some growth. This is not unique to Trek, the other major manufacturers also boast children’s specific geometry. The fork is rigid which was the primary reason I chose this bike over the equivalent priced Cannondale. A child can learn on a rigid bike, and when you consider the quality and weight of sprung forks on children’s trail bikes it seemed a no brainer to me to go rigid.  Trek seems to understand this as well. Their lower end 20″ kids mountain bikes have suspension up front, but their flagship Superfly 20″ is rigid. The fork, like the frame, is Alpha Aluminum with the dropouts welded completly around and machined. The head tube is oversized and houses a threadless headset like your typical adult bike.


A short Bontrager Race Lite, 31.8mm, 7 degree stem holds Bontrager Low Riser 31.8mm 15mm rise bars. Thin Kraton grips provide a comfortable interface between your little rider and the bike.  Joey’s average sized 6 year old mitts fit comfortably on the bars.  The brake levers are designed for kids, the throw can be adjusted very close to the bars and they still pull enough cable to actuate the generic v-brakes with tragic endo force (we experienced this once already). The shifting is handled by a 6 speed Shimano Tourney Twist shifter.


The drivetrain is a 1×6 setup with the chain being guided up front in typical kids bike bashguardlike fashion. A Shimano Tourney TX35 derailleur handles the shifting in the rear. Remember this is still a bike retailing at $419, the derailleur reflects that price point. The size of the derailleur leaves enough ground clearance which is a real concern when you are riding 20″ wheels.  With that said, the lower pulley does ride much closer to the ground than your adult bike, so if you get into what you think is low field grass, be aware that your little one’s bike might still be pulling stuff into its drivetrain. I don’t believe that is avoidable.  The crank set is an alloy three piece set with a 32 tooth chain ring, again appropriate for the price point, and more than adequate for the 45-100lbs of rider weight it’s meant to support. The cassette is a Sun Run 14t-28t.  The range of gearing is wide enough to tackle steep hills and still spin at 20 mph on the high end. The gear spacing is wide enough (physical spacing on the cassette) to ensure smooth shifting with minimal adjustment.  We all know how it is when our chain starts to dance between cogs and we adults usually can tweak it in, but for a six year old learning to shift that frustration could be a real game changer. As an aside, I personally would love a 1×6 setup on my own bike. Keep a wide ratio, run a thicker chain, smaller derailleur, and never worry about a finicky setup… who’s with me? Probably nobody, oh well I’ll stand alone on that. The pedals are kids sized nylon pedals. I’m not rushing to replace them, he can wait awhile to earn the deep purple shin scars.


Aluminum machined rims laced to Formula FM21 32 hole hubs appear high quality, and are light weight.  The skewers are a cool looking anodized red.  They are not quick release and require an allen key for wheel changes. This is just one less thing for your kid to mess with. Carry your multi-tool on the trail. You won’t get a six year old to happily push a bike with a flat for very long. The tires are Bontrager 20×1.85 and have a tread pattern that is adequate for the trail, but also seems to acknowledge that your child is going to spend a lot of time on pavement too.

All in all the bike’s set up seems to be well thought out, the componentry it appropriate for children, and a reasonable value for this price point. Plus it looks cool and classy. What boy doesn’t like fire engine red? (Red is the only color offered in America on this bike.)

Riding the Trek Superfly 20

As we get into the actual performance review let me start by naming the elephant in the room. You are going to buy this bike as much for you as you are your six to eight year old. They are clamoring for a bike, but they do not care about an oversized headtube, Alpha Aluminum, or machined breaking surface on their rims. Truth be told it is YOU that wants your kid to have the best, not them. I think that is great! Vicarious living has gotten an undeserved bad name in our society. We should push our kids into things that we know bring joy, it is foolish to make them figure everything out on their own under the guise of giving them ‘freedom’. If we want them to enjoy mountain biking, a nice bike helps.

The first thing I noticed as my son took off on this bike was that he looked like a mountain biker and not a little kid on a BMX bike. If he were far enough away and not around anything to gauge size against you’d be hard pressed to tell whether he was a kid on a 20″ or an adult on a 26″. This is to say that this really is a mountain bike and you can expect your child to be positioned like a trail rider. Joey’s handlebars are about level with his seat and as he grows and we raise the seat his riding position will become even more ‘adult’.  Even with seat and bars level this is a significant departure from the department store hand-me-down BMX bike he learned to ride on. I presume that most people in the market for this type of bike have a child that is coming off of a 12″ or 16″ wheeled bike.  Note that their riding position will be significantly different.  Fortunately kids adapt quickly, in Joey’s case the adaptation was instant.

The first hurdle we faced was using hand brakes instead of the coaster brake. Trek spec’d generic v-brakes and their ‘Dialed’ levers. This spec is more than enough to stop all 58lbs of my son on a dime. Strong brakes made the transition from coaster to hand brakes seamless. Disk brakes would have been a nice addition just for the ease of adjustment, but as far as stopping power they would be entirely unnecessary.

The next hurdle was learning how to shift.  The Shimano Tourney Twist fits his hand perfectly and was easy for him to turn. I tried not to explain too much about shifting right away to him, instead I told him to play with it while he pedaled. Again, kids adapt and learn quicker than we do. When we got out of the parking lot into soft grass I watched him downshift, when we were on pavement he’d upshift. He figured it out with ease. It is helpful that there are not too many gears to think about, and the shifting is spot on so far. The 1×6 spec is perfect for a young child learning to ride.

After getting a feel for the bike I took him down a local canal trail that has a number of small sections of single track going off of the sides of it.  It was like a whole new world opened to him, and I could see in his eyes that moment… the moment that we all chase… the joy of the first real ride.  Some of these single track sections have slightly tricky climbs, at least tricky enough that I didn’t expect a six year old to make it.  He climbed them no problem.  In large part I give credit to the bike.  Unlike most kids bike offerings, even from brands like Specialized and Cannondale, this bike weighs well under 20lbs (19.2lbs).  When the rider weighs under 60 every pound is significant on a climb. The fact that the 6 speed drive train can handle terrible shifting, the bike is super stiff, and the geometry places him in a proper riding position are huge helps as well.

Descending hills was where we ran into the most trouble. Joey got a little scared at one point and hammered the brakes (did I mention they have ample power), and he took his first trip over the bars. He got over it quickly and got right back at it. I looked over the bike when we got back to the van, nothing appeared to come out of adjustment.  As our ride progressed he began riding faster and faster, both on climbs and descents. A well thought out, well built piece of equipment makes the learning curve much faster.

Cruising around on pavement was pretty impressive as well.  Running in the 14 tooth cog Joey was able to touch close to 20mph, a serious rush for a 6 year old.  He’s already taken it off ramps and over curbs, through mud, and even managed already to get a tire puncture back in a construction area. The bike seems to tell him that he can do anything, and I think the bike is telling the truth.

As a dad I’m proud, and at this point I think the purchase was a total win.  Of course time will tell, and I will check back in at the end of the summer to tell you how this bike held up to a year of use.

If you are having a hard time justifying $419 for a kids bike, I can understand that.  I’d just say this to those who might hitch at that cost; compare it to a video game system with enough games to keep your kid’s interest, or an iPad or iPod with enough apps to be worthwhile. Often those devices drive a wedge between you and your child, and still cost as much, if not more than the bike. This purchase will have the opposite effect on you and your child’s relationship. The Mountain Bike Life lived together with your children is priceless. After that first ride you won’t question the purchase price again.

About Author