Prevelo Alpha Three 20″ Kids Bike Review

My son charges up the hill, pedaling out of the saddle, and maneuvers over a rooty section of trail. He cleans it, compliments himself, and powers on.  My husband and I share a quick glance of disbelief — and pride.

I never would have imagined that a just-turned-5 year-old could climb like this, or that they’d be able to manage a 20″ bicycle with gears. But here we are. When Jacob at Prevelo Bikes suggested that he thought my son was ready for the Prevelo Alpha Three, I was skeptical. It weighs quite a bit more than the Prevelo Alpha Two (the 16″ bike that my son was currently riding), and it has an eight-speed rear cassette. I wasn’t convinced our little guy was ready for a bigger bike or gears, but I was game for giving it a shot. As it turns out, he figured out the shifting with 10 minutes of practicing, and any issues due to added weight have been negligible compared to the gains in his climbing ability with the addition of gears.

Prevelo Alpha Three Review

For parents interested in introducing gears at an early age, and for kids who have already mastered pedaling and bike handling, the Prevelo Alpha Three is the ideal 20″ bike. It doesn’t have the front suspension or the disc brakes of the Prevelo Zulu Three, but it provides big wheels and gears for young kids who can’t yet fit on other 20″ bikes.

Review in a Nutshell


  • Low minimum seat height and standover height
  • 8 speed Shimano drivetrain
  • Beautiful aluminum frame
  • Kenda Small Block Eight tires


  • Trigger shifters are challenging for little hands

Price & Where to Buy:

Prevelo Alpha Three Detailed Review

Frame and Components

Prevelo Alpha Three Frame

The frame, the wheels, and the rest of the component build are top-notch.  Had we speced out a 20″ bike ourselves, we would have built it up just like this.

The naked aluminum frame looks good and is well-built.  It has clean, solid welds, and doesn’t need paint to attract attention.  The frame allows internally routed cables to keep things clean and tidy looking.

Other high-quality components include Kenda Small Block Eight Tires, Tektro brakes, and a Shimano drivetrain.  The Small Block Eight tires are miniature versions of the popular adult mountain bike tire (one of my faves) and provide a smooth fast-rolling ride experience.  The Tektro handbrakes boast easy-to-reach, easy-to-pull brake levers, and good stopping power even on steep hills and off-road.  Finally, the Shimano drivetrain provides clean shifting even for less-than-perfect-shifting kids.  (I’ll discuss the drivetrain more later on).

Kenda Tires on the Alpha ThreeOther nice-to-haves include a quick release seat collar and wheel skewers.  The quick-release seat collar allows for on-the-trail seat drops and easy adjustment of seat height as kids grow.  I also love finally having my son on a bike with quick release wheel skewers; this is a new experience as all his bikes up until this point have had bolt-on wheels.  The quick-release skewers allow for quick tire changes and easy installation.

Finally, it’s worth noting the custom-made crank arms.  They are sized perfectly for young riders and efficiently transfer power to the rear wheel.


Prevelo Alpha Three Kids Bike

The Prevelo Alpha Three has a minimum seatpost height of 20.7″ and a low minimum standover height. My son has a 19″ inseam and fits on the bike comfortably, although if your child isn’t already a comfortable pedaler I would wait until their inseam is closer to 21″.  Jacob also swapped the standard stem for a shorter one which I would recommend if your child is still on the smaller side.

For a 5 year old, the bike is going to be less nimble than a smaller frame. On his Prevelo Alpha Two for instance, my son is easily catching big air on the pump track and off of jumps, but struggles to get the Alpha Three up much at all. There have been a couple of times that he’s had crashes and I know that it is simply because the bike is still a bit much for him to handle at times. That said, I’m still not sorry that we’ve introduced him to it, because the gear and bigger wheel size really do make a difference especially on the trail.

For a 6 year old, or kids already in a 6T pant, the frame is ideally sized with some room yet to grow.


The geometry of the Prevelo Alpha Three hits a sweet spot.  It is aggressive enough to be ridden on serious trails, but upright enough to inspire confidence and maneuverability.  The long wheelbase provides stability, and the down-sloped top-tube allows young riders to easily mount and dismount.  We appreciate that the bottom-bracket is low enough to provide a low center of gravity, but high enough that it can easily clear obstacles.  Lastly, the low-rise handlebars are wide and provide excellent control for young riders.

The only riders we wouldn’t necessarily recommend the Alpha Three for are kids just learning to pedal or particularly timid children.  They might be better off with a bike with slightly less-aggressive, more upright geometry.  (The Islabikes Beiinn and Woom 4 are two examples).

Gearing & Shimano Rear Derailleur

For kids who are ready to learn to shift, the 8-speed Shimano rear derailleur provides a nice range of gears. In the lightest ring (34 tooth), my son has seen a noticeable improvement in his ability to climb compared to a singlespeed.  On the other end of the spectrum, the top-end gears allow him to go fast on flat and downhill sections, and means that he’ll never be spun out again.

Compared to an adult bike, the derailleur cage is laughably short and the rear derailleur wheel is  comically large.  This is necessary of course due to the smaller wheels and proximity to the ground, and even when riding technical singletrack the derailleur has had plenty of clearance.

Prevelo Alpha Three Shimano Rear Derailleur

While I was concerned that, at 5, my little guy wouldn’t have the coordination and skill to understand when to shift up and shift down, my worry seems to have been for naught. He took to it immediately. This may not be the case for every 5 year old. I would certainly wait until a child has mastered other skills–pedaling, braking, cornering, etc–before adding a new dimension.

The display window on the shifter shows the gearing (1 being easiest, 8 being hardest), and seemed at least initially to help him “feel” where he was on his rear derraileur.

The shifters themselves (Shimano Acera Rapidfire Plus) are somewhat challenging to operate. Compared to my own Shimano Deore XT trigger shifters, they do require a bit of strength to push which is tough for little thumbs. While the kiddo has already improved with time and practice, this does seem to be the one “con” on the bike.  Higher end trigger shifters would help alleviate this problem, but would of course add expense.  Grip shifters could make the learning curve easier for young kids, but come with their own set of issues.


Prevelo Alpha Three

At 19 lbs, the Prevelo Alpha Three is awfully lightweight compared to most 20″ kids bikes and on par with all higher-end bikes (see the comparison chart below).  That said, it is only a few pounds lighter than my  full-suspension mountain bike with 27.5″ plus-sized wheels.  My bike weighs about 20% of my body weight.  In comparison, the Prevelo Alpha Three weighs more than 50% of my little pint-sized five year old’s body weight.  Despite this weight disparity, the low gearing on the Alpha Three allows it to be maneuvered easily uphill and helps make up for some of  the heft.

Comparison to the Prevelo Alpha Two and the Prevelo Zulu Three

Prevelo Comparison

Deciding whether the Alpha Two, Alpha Three, or Zulu Three is the best choice for your child is based on three basic factors: 1) inseam length, 2) ability level, and 3) preferred type of riding.

The most obvious (and important!) thing is your child’s inseam length. A bike that is too big (or small) for your child will result in a sub-optimal, and perhaps even dangerous riding experience. As mentioned earlier, wait until your child has a 19″ to 21″ inseam length before attempting to move up to the Alpha Three. The Zulu Three *has a slightly larger minimum seat height and your child needs to have an inseam length of at least 21″ to fit comfortably on it.

As for ability level, don’t push your child into a bigger bike or gears until they are truly ready. They should be riding confidently, quickly, and joyfully on a 16″ bike before attempting a 20″ bike. The bigger frame will also give them trouble if they haven’t yet developed good bike handling skills.

Finally, your child’s preferred type of riding should be taken into account. Assuming your child is large enough, the Zulu Three is going to be the preferable bike if your family does a lot of mountain biking. The suspension fork and disc brakes will make a huge difference in their enjoyment and ability. If, on the other hand, you are buying a bike for riding around town and to school, stick with the Alpha Three. The extra weight and cost of the Zulu Three is unneccessary for street riding.

Comparison to other 20″ Bikes

So we’ve convinced you the Prevelo Alpha Three is nice, but how does it compare to other 20″ bikes?  Here’s a comparison to a couple other high-end 20″ kids bikes.  These are all fully-rigid (no suspension) for an apples-to-apples comparison.   If you are looking for a 20″ bike with suspension, check out our article The 5 Best 20″ Mountain Bikes.

BikeWeight (lbs)Frame Material/DesignDrivetrain/ShiftersBrake SystemRimsTires
Co-Op Cycles REV 2020.2Alu AlloySinglespeed Coaster / rear v-brake (Tektro)In HouseKenda Kontact, 20" x 1.75"
Vitus 2020.9Alu AlloyShimano, 7-speed, trigger shifterV-brakes (Tektro)In HouseKenda Small Block Eight Pro 20 ×1.5
Raleigh Rowdy20.4Alu AlloyShimano, 6-speed, grip shifterV-brakes In House20 x 2.125"
Norco Roller 20NAAlu AlloySingle SpeedV-brakes (Tektro)In HouseNorco 20” x 2.1”
Priority Start 2019.5Alu AlloyGates Belt Drive, Shimano Next 3-speed hubV-brakes In HouseKenda 20 x 1.9
Guardian AIROS 20 1-speed19.5Alu AlloySingle SpeedV-brakes (SureStop)In HouseKenda Kontact, 20" x 1.75"
Cannondale Quick 20 20.2Alu AlloyShimano, 7-speed, grip shifterV-brakes (Promax)In HouseKenda Small Block 8, 20 x 1.5
Pello Reddi 2017Alu AlloySinglespeed V-brakes (Tektro)AlexKenda K-Rad 20x1.95
Guardian AIROS 20 6-Speed21.2Alu AlloyShimano, 6-speed, grip shifterV-brakes (SureStop)In HouseKenda Kontact
Woom 417.9Alu AlloySRAM, 8-speed, grip shifterV-brakes (In-House)Supa Dupa Hoops (In-House)Schwalbe Little Joe 20 x 1.4
Cleary Owl 2021.0SteelSturmey Archer Internal 3-speed Hub, trigger shifterV-brakes (Tektro)AlexKenda 20 x 1.9
Prevelo Alpha 318.9Alu AlloyShimano, 8-speed trigger shifterV-brakes (Tektro)In HouseKenda Small Block Eight Pro 20 ×1.5
Pello Rover 2018.5Alu AlloySRAM, 7-speed, grip shifterV-brakes (Tektro)AlexKenda K-Rad 20x1.95
Frog 5519.4Alu AlloyShimano, 8-speed, trigger shifterV-brakes (Tektro)In HouseKenda K1153 20"x1.75
Early Rider Belter Urban 2016.3Alu AlloySturmey Archer 3-speed hub, grip shifterV-brakes (Tektro)In HouseMaxxis DTH 20 x 1.5
Guardian Ethos 2020.7 (small)SteelSinglespeedV-brakes (SureStop)In House
Batch Kids Bicycle 2019.2Alu AlloySinglespeedCoasterIn House
Specialized Jett 2019.3Alu AlloyShimano microSHIFT, 7-speedV-brakesIn HousePathfinder Sport, 20x2.0"
Park Cycles 2023.0 Alu Alloy7 speedDisc brakesIn House20 x 2.1″
Belsize 2014.82Alu AlloySingle SpeedV-brakes (Tektro)In HouseKenda CST, 20x1.5
Polygon Premier 2021.8Alu AlloyShimano, 7-speedV-brakes (Promax)In HouseKenda 20×1.75"


For smaller riders that are ready for gears, the Prevelo Alpha Three is the ideal 20″ bike. The lightweight aluminum frame, high quality components, and 8-speed rear cassette will take your child to the next level in their riding ability.

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Disclaimer:  Prevelo provided us with a bike to test for this review.  We were not paid nor did we receive any other kind of compensation, and all opinions are our own.  Some of the links in this review are affiliate links, meaning if you click thru and make a purchase, we receive a small commission.

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