Trailcraft Blue Sky – 20″ Kids Mountain Bike Review

If you’re in search of a high-end, lightweight, customizable 20″ kids mountain bike, look no further than the Trailcraft Blue Sky 20. This 20″ pony is spec’ed as good as it gets for kids bikes, and is the lightest 20″ kids mountain bike on the market!

Every Trailcraft model comes with several spec level and bright color options, but because the bikes are built from the frame up in the USA, you have the ability to customize even further by contacting Trailcraft’s family-owned team.

If you know the value of a lightweight bike for a lightweight kid, and geek out over the components on your own bike, the Trailcraft Blue Sky 20 will be a dream experience for you and your grom. Read our full review below for our take.

Trailcraft Blue Sky 20 Overview

RATING: Exceptional

MSRP: $1,899 (Pro Build)

SEAT HEIGHT: 24.4″ – 28.6″ (Minimum can be lowered by about 1.5″ by cutting seat post)

SPECIFICATIONS – Pro Build

WEIGHT: 19.0 lb., tubeless and with included pedals
FRAME: Aluminum Alloy
BRAKES: Shimano Deore 6100 Hydraulic Disc
GEARS: 10-speed
GAIN RATIO: 1.6 to 5.1 (28T) or 1.7 – 5.5 (30T)
SHIFTERS: Shimano Deore Trigger
DERAILLEUR: Shimano Saint 10 speed
WHEELS: Stans Crest MK4 
TIRES: 20 x 2.2, tubeless ready, Schwalbe Rocket Ron or Crown Gem
WHEELBASE: 864 mm

View on Trailcraft

What we love about the Trailcraft Blue Sky

• Super light weight build for easier handling and climbing for young riders – the lightest 20″ MTB on the market!
• Exceptional components (like a Shimano Saint clutch derailleur) for best performance
• Comes with tubeless ready rims (taped!) and tires, and can even be ordered with tubeless already set up
• Super customizable – chain ring comes in 28T or 30T, and two build-quality options. Can be further customized upon request.
• More bright color options (FIVE!) than any other kids mountain bike brand
• The only 20″ MTB we know of to have eyelets and enough room for a water bottle on top of the down tube

What you should know before you buy

• Specs on components do sometimes vary based on availability, so if specific components are important to you, be sure to confirm before ordering
• An optional dropper post can be order and installed prior to shipping, but most kids this age aren’t the best fit for the dropper. (See below for additional info.)
• If you’re wondering why the Blue Sky has QR skewer axles and not thru axles, it’s to save on weight.

Trailcraft Blue Sky Model Options

The Blue Sky 20 comes in two different builds – the base level Special, and the upgraded Pro. (Bigger wheel sizes have 5+ build options.) Both models offer exceptional components, but there are a few differences that make the Pro a $400 – $500 upgrade. The components on both models have changed over the years, but at the time of this review, here are the primary differences:

• The Pro is about 1.5 pounds lighter due to a few components that are lighter
• Shimano Deore hydraulic disc brakes come standard on the Pro. The Special features Shimano MT-201 hydraulic disc brakes.
• The Pro features a Shimano Saint derailleur and Shimano Deore trigger shifter, while the Special features a Microshift derailleur and trigger shifter
• Upgraded Stans Crest MK40 rims on the Pro
• VP composite pedals with metal pins on the Pro are trailworthy and don’t need to be swapped out

Trailcraft Blue Sky Review – Results of our Test Rides

Our primary test rider is an aggressive and experienced 5.5-year-old shredder who has spent the last year testing trailworthy 20″ kids mountain bikes. For this review we tested the Blue Sky on our rocky and rooty Texas cross country trails, as well as jump lines at our local bike park.

Who is the Blue Sky 20 Best For?

We’ll talk more about weight later, but as the lightest-weight 20″ hardtail on the market, the Blue Sky 20 is an exceptional option for almost any serious kid shredder. Tackling obstacles, climbs, and distance is just easier with a lighter bike.

With an air suspension fork that’s better than most kids’ forks out there, the Blue Sky would also be a great choice for kids who will be regularly riding trails with lots of chatter, but especially aggressive kids who will eventually be going over drops or jumps at speed.

Sizing – Transitioning from a 16″ to a 20″

The Blue Sky has a seat height range of 24.4″ – 28.6″. That minimum seat height is about 1.5″ higher than competitors like woom and Prevelo, but you can cut the seat post to decrease minimum seat height by about that same 1.5″.

That said, compared to woom and Prevelo, the Blue Sky has a higher bottom bracket and longer crank arms. Combined together, slamming the saddle all the way down will create a tighter knee bend at the top stroke, making it harder for the shortest of riders to get an efficient pedal stroke in.

If you’re trying to transition your child from a 16″ bike, be sure to measure their inseam to make sure they will fit on the Blue Sky. 20″ mountain bikes tend to be a tad bigger than a standard 20″ bike, so there could be a small gap in sizing.

Also be aware that some kids (especially younger kids still mastering their MTB skills) may prefer to ride with the saddle lower on a 20″ MTB that you would expect. Our 5.5-year-old rider is 48.5″ tall with a 22.5″ inseam with her shoes on. While she rides a neighborhood bike with the saddle set about 3-4″ above her inseam, on a mountain bike she prefers just about 2″. This increases her confidence that she can set her foot down and prevent herself from crashing if things get tricky.

Geometry and Performance

Just like there’s no perfect mountain bike for adults, there’s no perfect mountain bike for kids either. What’s important for one type of trail terrain and one child’s body proportions will vary. That’s why we’ll always offer you comparisons in our reviews. That way, you can decide what’s best for your child and their riding style.

To get a feel for the Trailcraft’s geometry, we’ll compare it to two other 20″ hardtails we’ve been riding for the last year. Brands don’t always offer every spec, so some of the specs below have been measured by us personally.

While you could pick apart and compare every spec for days, when we had our 5-year-old tester ride each of these bikes back to back, the one spec that immediately stood out to us was the stack height and handlebar height.

Below you can compare her body position (48.5″ tall with shoes) on the Blue Sky with both the Prevelo Zulu Three and woom OFF 4. All three bikes have saddles set to about 24.6″ – 24.75″.

Blue Sky 20 vs. Prevelo Zulu Three

Blue Sky 20 vs. woom OFF 4

The Blue Sky has both a lower stack and lower handlebars. The flat handlebar has essentially no rise, and the three headset spacers are already below the stem, so the handlebar is as high as it’s going to get unless you swap in a bar with more rise.

While our rider had no issue with the lower stack height, she’s still riding with the saddle near the lower end. If we were trying to get another few inches out of the saddle, the lower stack could get less comfortable as she’s growing out of the bike.

Trailcrafy Blue Sky 20 Components Round-up

Just like with an adult mountain bike, you pay more for essentially three things – less weight, better components, and brand preference. How much each of these is worth to you will determine if the price of a Trailcraft makes sense for your family.

The components we’ll be discussing below are for the Pro model, although the Pro and Special builds share some of the same components. Additionally, the model we received didn’t entirely match the specs of the Trailcraft website, so if you’ll be disappointed if you don’t get these exact components, make sure to double check with the Trailcraft team before you place that order.

Also, remember that one of Trailcraft’s main selling points is customization. If you have a particular component in mind, be sure to contact Trailcraft to see if they can build it that way so you have less upgrading later.

Weight

With other brands now also producing extremely high-quality, kid-focused mountain bikes, one of Trailcraft’s primary differentiators continues to be its low weight. Here’s a comparison of other exceptional kids 20″ hardtail mountain bikes with their corresponding MSRPs and weight (with pedals). The Blue Sky Pro and Special builds are the lightest in the market.

How important is weight? It’s an absolute make or break for kids. But how much you want to pay for less weight might be a make or break for parents.

Let’s break it down by comparing your own bike to your weight. For me, at 5’10 and 150 pounds, my 31 lb. carbon Santa Cruz Tall Boy is 21% of my weight. Our family’s 36 lb. aluminum Specialized Stumpjumper is 24% of my body weight.

Our very solid 5.5-year-old rider is 56 lbs. The lightest 20″ hardtail on the market, Trailcraft Pro, is 36% of her body weight. For kids, this is exceptional. The Prevelo Zulu Three, which is another exceptional bike but almost 5 pounds heavier, is half the price but 43% of her bodyweight.

This sturdy, very strong, and aggressive rider has been executing shorter climbs on the Zulu for the last year. But even for a strong, heavy kid, the weight difference on the Trailcraft was noticeably helpful on trail rides.

We live in Texas where there are no long climbs or descents, but a lot of short burst climbing with rock and roots often involved. Riding the Blue Sky, our young shredder seemed to pop over those obstacles with newfound ease and also made quicker work of those short climbs.

In the end, weight does matter. Especially for kids, and even more especially for petite or lightweight riders.

Air Suspension Fork

The Blue Sky’s air fork has carbon lowers to decrease weight, 80mm travel, lockout, adjustable compression, and adjustable rebound. And while yes, these features are impressive, like with every 20″ and 24″ kids mountain bike we’ve tested, you need to be aware that many kids may not weigh enough to utilize the full travel of the fork.

That said, this Trailcraft fork was more responsive than other hardtails we’ve tested. For our 56-pound test rider (48.5″ tall with shoes, and heavier than your average rider), we initially ran the psi at 25 to get 24% sag, and an extension of 62mm, but she bottomed out the fork just going over the curb in front of our house.

We then increased the psi to 33. At 33, we didn’t get the full 80mm extension on the fork, but pretty close at 74mm. On a true aggressive trail ride, she got that full 74mm pretty quickly, so I added some air to the fork trailside. 40 psi with a 79mm of travel extension seemed to be the sweet spot for her to maximize her use of available travel.

With lightweight kids and air forks, there is limited room to adjust the psi and still have enough air in the chamber, so unless you’re willing to pay a lot for a top-of-the-line fork, you’ll need to set your expectations that the fork is probably not going to work as well as yours does.

However, this Trailcraft fork is easily one of the best we’ve come across in the kids MTB world, as long as you take time adjusting and testing the psi and sag with your rider to maximize its benefits for their weight.

The Trailcraft fork features adjustable rebound, and once we got the psi set correctly, adjusting that red knob did make a noticeable difference in ease and speed of rebound between the highest and lowest settings.

Is adjustable rebound really necessary for a kids air fork? Debatable, but it’s fairly common on high-end kids mountain bikes – probably in large part because parents expect to see the same features on their kid’s bike that they have on their own. 🙂

Hydraulic Disc Brakes with Short Reach Levers

Hydraulic disc brakes are expected on a legitimate kids mountain bike, and the Blue Sky’s Shimano Deore brakes do a bang up job. While not Shimano’s highest-end line, the Deore offers more than enough dependability and stopping power for the speed and aggression that kids this age will be riding.

Short-reach brake levers are also the norm on quality kids’ bikes, but these levers are also short-length, which we don’t see that often. While they are still long enough for small hands to pull with a full hand, their short length allows you to more easily set up your levers for 1-finger braking.

That said, be sure to temper your expectations. While the Deore levers are plenty sensitive for 1-finger braking, not all kids this age are going to be ready for that. In the hierarchy of MTB skills kids need to learn, level pedals, getting out of the saddle, and shifting usually need to come before 1-finger braking.

Our primary tester has been mountain biking for over two years, and has been on a 20″ hardtail for the last year. At age 5.5, we’re just now trying to teach her to stop using her whole hand to brake, and she usually forgets about 1-finger once she gets into a ride. If your child is older, you’ll probably have more success!

1 x 10 Shimano Saint Derailleur

The Blue Sky’s Shimano Saint clutch derailleur shifts quickly and smoothly up and down the 11-36 Sunrace cassette, which is paired with either a 28T or 30T chainring – you choose at check out. (Why a Sunrace cassette and not Shimano? Weight savings wherever possible!)

From the gain ratios we calculated, there’s little difference on the low end (granny gear), but a bigger difference on the high end. 30T offers 1.7 – 5.5 gain ratio range, while the 28T is 1.6 – 5.1. Trailcraft recommends the 28T for riders who will be tackling big climbs regularly.

We live in generally flat, cross-country style terrain with shorter, punchy climbs, and use a tow rope for extended climbing when we head to Bentonville, so we chose the 30T chainring.

One thing we always pay attention to with 20″ kids mountain bikes is ground clearance for the derailleur when at its lowest point. With wheels that small, derailleurs can end up hanging precariously low to the ground and subject to damage from rock or root obstacles.

Short cage derailleurs have been a huge help to small mountain bikes, and the Shimano Saint derailleur is the best we’ve seen. It has significantly more ground clearance than other bikes in our stable – a whopping 4.25″ compared to the woom’s 3.25″ and Prevelo’s 3.6″.

The clutch on our bike came in the OFF position. Be sure to check yours and set it to your preference, or based on the terrain you’ll be riding.

Trigger Shifters and Ease of Shifting

Since this will most likely be your child’s first introduction to gears, it’s particularly helpful that the Blue Sky’s trigger shifters are easy to use and small-hand-friendly.

The Shimano Deore trigger buttons are a thumb/forefinger, push/pull combo with minimal tension and relatively short throws on the thumb button.

The woom OFF models feature SRAM X5 double thumb triggers, while the Prevelo Zulu feature Microshift double thumb.

The three brands are all kid-friendly and easy to engage, but in a head-to-head test, the Zulu’s Microshift thumb button is slightly easier to push than the others.

PARENT NOTE

We’ve had many years of experience teaching kids to use gears on their first 20″ bike, and it can be quite a process! Depending on your child’s age and ability, they may not have the developmental ability to ride and shift gears at the same time.

How quickly you try to introduce your child to gears is up to you, but don’t be afraid to just set the cassette to a middle gear before the ride to keep it simple for your grom. No matter when you decide your child is ready to experience the benefits of shifting while riding, patience and a lot of pre and during-ride parent coaching will be required!

Wheels and Tires Tubeless Ready

Flats on the trail are a pain, and multiply that by 20 if you’re riding with your kids. Tubeless tires are a game changer, and Trailcraft has made that easy for you. And of course you have the added benefit of running lower PSIs for more cushioning and traction on the trail.

The super light Stans Crest MK4 rims come taped and the tires are also tubeless ready, so conversion is a quick process. Trailcraft will even convert it for you… shipped ready to roll with tubeless valves that are color matched to your bike’s frame.

The Pro Blue Sky we received is built with cross country Schwalbe Rocket Ron tires, which are popular for kids mountain bikes because of their light weight.

We’ve used the Rocket Rons on other kids mountain bikes that were not tubeless, and found the thin sidewalls can be problematic for punctures. Just another reason to convert these babies to tubeless!

If you have a specific tire preference, be sure to ask. The Trailcraft team is happy to accommodate if they can get their hands on what you’re requesting.

Note: In previous years, the Stans Crest rims came with color accents to match the frame. In 2023, the writing on the rims is gray/silver.

Dropper Post Ready

The Blue Sky comes dropper post ready, and can even be ordered with a dKS LEV Si 75mm dropper post already installed for an additional $200. With the dropper post installed, the new min/max seat height is 23.6″ – 26.5″. However tempting a dropper post may be, this is the one adult-necessary component that probably doesn’t make sense for most kids on a 20″ bike.

In addition to the complexity it takes to raise and lower a dropper post mid-ride, the raised height of the seat post is also a drawback. If your child cannot reach the ground with the dropper fully extended, this could create a dangerous situation if the dropper is accidentally engaged while they’re standing on the pedals.

That said, we know the dropper post is a super popular upgrade for the Blue Sky. We’ve offered our opinion, but feel free to do what your MTB instincts are telling you. 🙂

Water Bottle Compatible

Looking to carry a water in a bottle rather than a hydration pack? The Blue Sky 20 is the only 20″ mountain bike we know of that has eyelets for a water bottle above the down tube. That said, a 20″ frame has limited room, so you’ll need to be selective about the type of water bottle you use.

Our water bottles by Camelbak, Yeti, and Simple Modern have lids that were slightly too tall or wide. Our Polar Bottle 12 oz. Kids‘ lid was shorter and slightly more narrow, allowing it to be a perfect fit in our side entry water bottle cage.

Included Pedals Good Quality

The included pedals on the Pro build are actually pretty decent. VP Composite with metal pins, you don’t really need to swap them out unless you have a favorite pedal brand you’re loyal to. Our tester’s feet stayed well planted, even over the rough stuff.

Lock-on Grips

We appreciate the Trailcraft lock-on grips because they (obviously) stay in place, and are also easy to get off if you ever need to swap them out. Small diameter for small hands, there is nothing particularly noteworthy about them compared to other kids MTB brands, but they worked just great

Bottom Line on the Trailcraft Blue Sky 20

Ready to assemble your customizable Trailcraft Blue Sky 20? Exceptional components paired with a feather-weight build make this 20″ Trailcraft an ideal tool for growing the skills of your budding shredder.

Price tag got you a little wide-eyed? The Special build is still more lightweight than any other brand’s 20″ mountain bike and will save you about $400.

For more 20 inch mountain bike options, check out our 9 Best Boys and Girls 20 Inch Mountain Bikes article.

FTC Disclosure: Affiliate links are included in this review.  No monetary compensation was provided for this review, however, the reviewed product was supplied by the manufacturer or distributor to help facilitate this review. All opinions and images are that of Two Wheeling Tots LLC.  All content and images are copyrighted and should not be used or replicated in any way. View our Terms of Use.