# Trek superfly 20 - 19lbs



## crotched (Mar 29, 2014)

I purchased a Trek Superfly 20 for my 7 y/o son 48". I was planning on getting him a 24" bike but after watching him on it, I felt it was too big and he was too stretched out to handle it. One of the criteria I had was I wanted it to be sub 20lbs and no front shock, since at 50 lbs, what good is it. 

Now if the trails would melt.


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## GrayJay (May 16, 2011)

Nice option for a decently trailworthy off the shelf 20" bike. I like that they built an alloy V-brake rigid 20" fork for this rather than specing a cheap boat anchor of a suspension fork. 
Are the hubs quick release or nutted?


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## crotched (Mar 29, 2014)

hex nut with a quick release looking cover.


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## jmiklovic (Aug 21, 2013)

This is a great bike! We got my son one as well. I wrote a detailed review of it here if you are interested. I think it is lighter than 19lbs. I weighed Joey's and it came it a hair over 17.

The Mountain Bike Life: Trek Superfy 20 Initial Review - Cool Kit for the Kiddies or Dad Reliving Childhood Dreams?


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## CJH (Apr 21, 2004)

The geometry of this bike is not listed on Trek's website. Could Crotched or Jmiklovic measure the horizontal top tube and post it in this thread? Thanks.


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## jmiklovic (Aug 21, 2013)

CJH said:


> The geometry of this bike is not listed on Trek's website. Could Crotched or Jmiklovic measure the horizontal top tube and post it in this thread? Thanks.


Not sure the proper way to measure. It is 15.5" weld to weld 17.25" seat tube center to head tube center


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## jmiklovic (Aug 21, 2013)

That was actual not "effective" I can check the effective later tonight if you want


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## CJH (Apr 21, 2004)

jmiklovic said:


> That was actual not "effective" I can check the effective later tonight if you want


Yeah or I could snap a pic of how to measure effective (aka horizontal) top tube on my kids Hotrock 16 later. Then you could try to duplicate that on the Trek.

Have you ever seen a Cannondale Street 20 in person?


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## Sam25 (Sep 22, 2012)

Any further feedback or opinions on this Trek Superfly 20 bike? 

I am looking at getting a new bike for a kid who is 50 inches (127 cm tall) with a 21 inch (54 cm) inseam? Current bike is an Islabikes Cnoc 16 and Islabikes has changed the policy and no longer deliver where I am, so I need to find a different option. 

This bike seems fairly similar, seems light, but I am not sure about its quality and I dont know much about this Shimano Tourney gearing it has. 

I have another kid 3 years younger who will eventually inherit the bike, so quality + lightweight matters in this case and am willing to pay more for that, as long as the quality is there.


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## thesmokingman (Jan 17, 2009)

Sam25 said:


> Any further feedback or opinions on this Trek Superfly 20 bike?


The Spec Hotrock 20 seems to be a better foundation imo. The drivetrains are both similar so it comes down to the frame and fork for me. It's cheaper and the frame comes with disc tabs and a suntour disc fork that is easily modded for your child's weight. Btw, my 6 yr old daughter has inherited her brothers Hotrock 20 which weighs just over 22lbs.


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## Sam25 (Sep 22, 2012)

Thanks, but if I understand correctly, the Trek Superfly is an 18 lb bike? 

That's where the Islabike 20" size bike comes in and that's about the weight range I am looking for, plus as said, quality components and build. 

A 22 lb build I think would includes some unnecessary weight for a bike of this size to be ridden by a kid. I'm willing to pay a bit more for something good AND light, but for the money I want both of those things to be there.


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## ReXTless (Feb 23, 2007)

I just bought a 20" Islabike for my daughter. If that wasn't available, I would have gone to the Superfly without a second thought. It's a much better option than the Specialized.


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## Sam25 (Sep 22, 2012)

We took a trip to the bike store today to check out the Superfly. Weight was good and build quality seemed pretty solid. 

On the other hands, it seems the crank arms were a little bit long for the size and pedal position again a little bit wider than what was right for the child. Saddle on the bulky side but probably comfy.

Bike was priced right up exactly same as Islabikes charges - although it is maybe one notch below.

Will think it over a bit and decide.


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## Sam25 (Sep 22, 2012)

Made the purchase in the end. Will throw in some feedback here.

Seems to have been a good buy so far. Kid has taken to the bike like a duck to water. This was a step up in size from the previous bike (Islabikes CNOC 16) but all has gone very smoothly. No complaints all. There was a bit of unexplained ticking sound initially from the rear, but that sound has gone away.

One small concern is that the rear derailleur hangs a bit low for my liking, so we'll see how this pans out in the long run. 

Overall am satisfied with the Superfly 20. Would definitely recommend it to anyone who wants a solid but lightweight bike and does not want to deal with Islabikes' newly inflated egos.


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## CJH (Apr 21, 2004)

jmiklovic said:


> That was actual not "effective" I can check the effective later tonight if you want


Realized I forgot to follow up on this. I went out and snapped some pics of how to measure effective/horizontal top tube on my son's 2013 Hotrock 16.

Basically raised the seatpost up high enough so you can measure from the center of the head tube to the center of the seat post with the tape measure level, assuming the bike is on level ground.

My wife held the tape measure off screen while I snapped the pics and you can see we were right on the listed horizontal top tube length of 395 mm.

If someone with the Superfly 20 could measure the top tube I'd really appreciate it.


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## DrewKD (Jun 3, 2014)

I got my daughter a Superfly 24 D! She's only 5 years old but already out performs her GT 20" and definitely needed the upgrade. It is big for her so I swapped stems for a Race Face Respond 45mm instead of the stock Bontrager 60mm and a Truvativ Bar 580mm with no rise. I also swapped for a shorter seat moved all the way forward. She handles the bike like it's a part of her. It's still a little large for her as she's only 49" tall but this bike has drastically improved her bike skills. Now she loves Rock Gardens and Stream Crossings. With the front Suspension and Hydraulic Brakes she's much more confident and a lot faster with 24 vs 20. The bike weighs in at 26.7lbs. A bit on the heavy side for a HT but all kids bike are heavy..... she hasn't noticed the difference in weight, only how much more she can do on her new bike. Plus it matches my Superfly 100 PRO......... not that it matters or anything..... it's just cool!


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## CJH (Apr 21, 2004)

My wife was in San Diego and called me from a bike shop that had one in stock. I had her make a few measurements and compare the bike to other 20" kids bikes in stock and felt comfortable it would be a good fit for our son. At first I was thinking we'd just order one from our local Scheels, which is the only Trek dealer in our town, but the shop was so helpful to my wife and still had the box so we just had them pack it up and she brought it back on the airplane.

The bike was listed at $50 off and the shop charged nothing for packing so it worked out great for us.

We've had some lousy weather so not a lot of ride time here but the bike is nice and is the best 20" kids bike I've seen in person. Shop weighed it at 19 lbs.

Most of the components seem nice. I think the drivetrain is the weak link and where I'll look to upgrade this winter. He's not a fan of the grip shift and the bars are a bit wide and they will be my near future changes.

My boys are short legged so I do wish that Trek had done a bit more to lower standover but you can't have everything.


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## DrewKD (Jun 3, 2014)

CJH - If you're talking about Trek Bicycle Superstore, they are awesome! Huge inventory and great Clearance prices. I got my Superfly 100 pro from them..... $1400 off retail. I too modified my kids superfly to fit her better. standover sucks on all kids bikes. Cannondale makes a 24 with a slightly lower standover for future reference but the superfly 24 is a much better bike. Enjoy!


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## CJH (Apr 21, 2004)

DrewKD said:


> CJH - If you're talking about Trek Bicycle Superstore, they are awesome!


I'm not sure, but my wife described it as more of a smaller mom and pop type place, and they carried more than just Trek. Need to find out the name of the shop guy who helped her and have a pizza delivered on a day he's working.


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## redgecko (Jan 12, 2012)

CJH said:


> If someone with the Superfly 20 could measure the top tube I'd really appreciate it.


I recently picked up a Superfly 20 for my son. The effective top tube measurement is 435mm. We're really happy with the bike. 
He is 8 years old but short for his age at 125cm (49 inches)and the bike fits him well. 
The bike is very well made for a kids bike and nice and light. 
He adjusted to using gears very quickly and although there's only 6 gears, he can get up most trails.

Here's a very short video of him riding it last weekend at Gap Creek reserve in Brisbane.






The lack of suspension doesn't seem to bother him, although obviously from the video, some drops can result in a bit of a painful landing.


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## XJaredX (Apr 17, 2006)

Just because there's very little info out there on this bike, I thought I'd bump this thread with my experiences thus far after owning the bike for a few weeks.

My son is 47 inches tall, and 5 1/2 years old, if that helps anyone. Came from a Spawn Banshee which he will still use for general shenanigans, but he is rather mechanically oriented and so he's been begging for multiple gears, plus we wanted the larger wheels for better handling over the rough stuff when on singletrack.

The stock 150mm crank is absolutely ridiculous, I am not sure why Trek went there when they otherwise put a lot of thought into this bike. Until we had the crank issue sorted out we borrowed the 102mm, 28T crank from the Banshee. This actually was sweet gearing for off-road, but on the flats he was spinning out in the hardest gear.

We ultimately ended up doing the following:

-Sinz 120mm crank
-34T ring (smallest available)
-14-34 MegaRange 6 spd freewheel (done so he'd still have a nice gear for steep stuff even going from 28T to 34T up front)
-40mm Kona stem (takeoff from LBS owner's Process 153DL)
-Problem Solvers chain guide
-Specialized side entry bottle cage
-better bottom bracket, the stock one is crap

As it sits, with spare tube, it weighs 19.11 lbs. We're ok with that, it's at a weight where we don't need to go crazy with weight weenie stuff.

Only other thing we might change out are the tires, only for something bigger and knobbier, we frequently ride a flow trail made largely of shale. These work ok though and roll good on pavement. Overall, very happy with the bike. 

We were also looking at Cleary (loved it but wanted multiple gears), Isla (can't put larger tires on), and Spawn Savage (super nice and I can see where the money went in it's higher price, but much of that isn't needed by us. We are fine with Vbrakes, and the shifter and derailer on the Trek work just fine).


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## melchionda (Sep 25, 2012)

Nice!

I'm jealous of the rigid V-brake fork you have on that thing. I'm still trying to figure out how I'm going to get rid of the heavy SR Suntour fork off of our MT60.


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## Mark194 (Mar 3, 2012)

Thanks for creating this thread, Ordered my son one this morning!


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## XJaredX (Apr 17, 2006)

Mark194 said:


> Thanks for creating this thread, Ordered my son one this morning!


Cool! Just make sure you get a shorter crank. Easiest way is to have the shop swap it out for the one with two pedal holes that comes on the cheaper Trek MTB. But I love the setup we have.


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## Mark194 (Mar 3, 2012)

He races BMX, so we have lots of square tapered cranks in the toolbox!



XJaredX said:


> Cool! Just make sure you get a shorter crank. Easiest way is to have the shop swap it out for the one with two pedal holes that comes on the cheaper Trek MTB. But I love the setup we have.


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## Staticclover (Nov 22, 2014)

My son has been on this bike since May. It is a great bike, light, well built, and no heavy suspension fork that plague so many kid's mtb's. It looks badass and he is very proud of it. 
The thing I will mention is that it has gotten away from him a few times going downhill. I couldn't figure out why he was losing control until I read a comment somewhere else that said the bike is a bit "twitchy" and is better suited to good riders. My son gets better every time we ride, but I wouldn't say he is a "good" rider yet even for his age. I'm certainly no expert on bike geometry and I can't take it for a ride to see for myself, but I thought this might explain why it sometimes gets away from him on fast descents. 
I'd love for someone with more experience to look at the specs and give an opinion on this.

Superfly 20 - Kids' collection - Trek Bicycle

I may just be a typical parent looking for excuses for my perfect kid's clumsiness but he is usually at least adequate at all things physical. Just wanted to put this out there for people to think about before buying and to hear some opinions.


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## XJaredX (Apr 17, 2006)

^That's interesting. We haven't experienced that (yet), but we did run a shorter stem right off the bat. The head angle is 70 degrees, I haven't looked at the head angle of others except I just looked at the Specialized Hotrock 20 and it has a 69 degree head angle, I'm sure there's more to handling than just that number though.


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## Mark194 (Mar 3, 2012)

Any issue bolting up the 14-34 mega range? Did you have to add links to the chain?


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## Mark194 (Mar 3, 2012)

XjaredX -

Any issues bolting on the mega range? Did you have to add some links to the chain?

Thanks
Mark



XJaredX said:


> Just because there's very little info out there on this bike, I thought I'd bump this thread with my experiences thus far after owning the bike for a few weeks.
> 
> My son is 47 inches tall, and 5 1/2 years old, if that helps anyone. Came from a Spawn Banshee which he will still use for general shenanigans, but he is rather mechanically oriented and so he's been begging for multiple gears, plus we wanted the larger wheels for better handling over the rough stuff when on singletrack.
> 
> ...


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## XJaredX (Apr 17, 2006)

Oh, sorry! Forgot to look at this thread for a while. I honestly forget. I think no because we went to a smaller ring on front and it evened out?


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## redgecko (Jan 12, 2012)

Here's another video of my son on his Superfly 20. His older brother is following him on his Trek 3900 with a helmet-mounted camera. 
He loves the bike and is always keen to go out riding with his dad


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## XJaredX (Apr 17, 2006)

XJaredX said:


> Oh, sorry! Forgot to look at this thread for a while. I honestly forget. I think no because we went to a smaller ring on front and it evened out?


Wait I'm sorry I just revisited that comment I made and it didn't make sense. I know this is a few months late but I think we put a new chain on.


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## dbraxis (Aug 1, 2010)

melchionda said:


> Nice!
> 
> I'm jealous of the rigid V-brake fork you have on that thing. I'm still trying to figure out how I'm going to get rid of the heavy SR Suntour fork off of our MT60.


If your 20" or 24" kids bike has a suspension anchor(fork), all you need is a BMX or BMX cruiser fork to convert it.


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## sk1er18 (Jul 11, 2009)

Resurrecting an old thread here... 

I'm upgrading my son's Superlfy 20 that's getting handed down to my daughter. Frames currently with a friend for fresh paint. While he has it I was working on ordering to new parts. The bottom bracket is measuring 128.. to the ends of the taper, which seems ridiculous. 

What bottom bracket size did you all install? I'll probably go with some 120mm crank arms as well.


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## XJaredX (Apr 17, 2006)

sk1er18 said:


> Resurrecting an old thread here...
> 
> I'm upgrading my son's Superlfy 20 that's getting handed down to my daughter. Frames currently with a friend for fresh paint. While he has it I was working on ordering to new parts. The bottom bracket is measuring 128.. to the ends of the taper, which seems ridiculous.
> 
> What bottom bracket size did you all install? I'll probably go with some 120mm crank arms as well.


My LBS did it, not sure :/


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## thesmokingman (Jan 17, 2009)

Here's a hotrock 20 with Sinz 68x113 bottom bracket with a 130mm Redline Microline crank. I got the BB from treefort and cranks from amazon. The cranks were under 32 bucks lol. I think I lucked out they should be around 60 or more normally.


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## sk1er18 (Jul 11, 2009)

I went nuclear and just decided to cut one of our old cranks down to 120mm


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## melchionda (Sep 25, 2012)

sk1er18 said:


> I went nuclear and just decided to cut one of our old cranks down to 120mm


I needs to have this done too, but I couldn't find anyone who could do it and so gave up and just bought new ones. Did you use special tools to do yours? I've heard some people just use a hand drill.


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## sk1er18 (Jul 11, 2009)

melchionda said:


> I needs to have this done too, but I couldn't find anyone who could do it and so gave up and just bought new ones. Did you use special tools to do yours? I've heard some people just use a hand drill.


I used a friend's drill press to punch the holes accurately. Did everything else with my vice, saw, and grinder


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## GrayJay (May 16, 2011)

melchionda said:


> I needs to have this done too, but I couldn't find anyone who could do it and so gave up and just bought new ones. Did you use special tools to do yours? I've heard some people just use a hand drill.


melch- see my lengthy description of DIY hand-drill version of crank shortening on post #6 of;
http://forums.mtbr.com/families-riding-kids/sx-26-trek-4500-kid-build-961774.html


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