Prevelo Alpha Three 20″

Pedal Bike Review

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A top-notch, solidly-built bike perfect built for intermediate to advanced riders. Wide handlebars, a long wheelbase and trigger shifters make it an ideal ride for beginning mountain bikers or adventurous city riders.

View on Prevelo

Product Specifications

MSRP: $499

Recommendation: Exceptional

Seat Height: 20.7" - 25.5"

Weight: 18.9 lb.

Frame Material: Aluminum Alloy

Tire Size: 20" - geared

Brake Type: Tektro v-brake

Speed/Shifters: Trigger

Suspension: No

Handlebar: Low

Cassette: 11 - 34t

Chain Ring: 32t

Geared Bike Type: Beginning Cross Country

Gain Ratio: 2.1 - 6.7

Wheelbase: 835 mm

Available Online: Yes



The Prevelo Alpha Three 20″ is the perfect bike for intermediate to advanced riders who have an itch for adventurous or aggressive riding.  Lightweight with a long wheelbase and wide handlebars, the Prevelo Alpha 20″ provides a smooth and stable ride for everyday as well as adventurous riding.


Our resident 6-year-old tester is quiet by nature, but certainly feels the need for speed the minute he sits on a bike.  Aggressive and eager to ride, he doesn’t just ride bikes for us, he truly puts them to the test.  From steep downhills, jumps and curbs, to standing on his seat while riding or sliding through a tight turn, after testing out over 20 bikes over the last 2 years, he’s finally met his soulmate.  Working as one, it’s amazing to see him fluidly ride the Alpha Three through the neighborhood and parks.  In the month he’s tested out the bike, he’s quickly surpassed his older brothers in skill and determination to ride.

6-year-old Making Waves on the Prevelo Alpha Three

3 image collage - 6-yearold boy riding the Prevelo Alpha Three 20" kids' bike down a long grassy hill, standing next to the bike on the hill, and riding standing up on the edge of a curb.

Geometry and Weight

Lightweight with a low center-of-gravity and wide, low-rise handlebars, the Prevelo Alpha Three is perfectly balanced for young ambitious riders.  Weighing just under 19 lbs., the Prevelo is light, but its overall geometry makes it exceptionally nimble.  Compared to other 20″ bikes, our 6-year-old tester raved about how easy it was to steer and how well “it did what [I] wanted it to do!”

The Quick & Nimble Prevelo Alpha Three

Three image collage - 6-year-old boy on the Prevelo Alpha Three 20" bike about to ride down a grassy hill, riding down the street, and mid-way down a grassy hill.

The overall body position on the bike is on the aggressive side, meaning the rider is leaned forward more when holding the handlebars.  This positioning allows the rider to more easily shift their weight around, allowing more adventurous riders to tackle various obstacles.

Timid or beginning riders who are likely to stick to casual riding tend to prefer bikes with a more upright position, as more of their weight is centered over their hips which they are accustomed to when walking or running. Compared to the Guardian 20″ and the Islabikes BEINN 20″ Small, the Prevelo is the most aggressive as it has a longer frame that extends the space between the seat and the handlebars, stretching out the rider.  The Islabike is the most upright and the Guardian is in-between.

Aggressive Geometry of the Prevelo Alpha Three

Comparing body position on three different 20" kids' bikes, with the more aggressive being more leaned forward. From most aggressive to more upright - Prevelo Alpha Three, Guardian 6-speed 20", and Islabikes BEINN 20" small


Seat Height

With a seat height range of 20.7″ to 25.5″, the Prevelo Alpha Three is in the smaller range of 20″ bikes.  It was a great fit for our main 6-year-old tester in size 6 clothes with a 21″ inseam and still allowed for plenty of room for growth.

Our 5-year-old tester in size 5 clothes with a 19″ inseam was easily able to sit and pedal the bike, but the bike was too long for him to feel comfortable. The 16″ Prevelo Alpha Two was a better fit for him.

Our second and taller 6-year-old tester with a 24″ inseam  fit on the 20″ Prevelo Alpha Three just fine, but it provided little room for growth. While you wouldn’t want to buy this bike for a child this size, if he already owned the bike he could still ride it comfortably for several more months.

It’s important to note that seat height doesn’t always tell the whole story – the size of the frame needs to be considered as well.  Based on the actual seat height range and the long reach of this bike, the Alpha Three’s “good fit” inseam range is 20″ to 24″, while its “best fit” inseam range is from 21″ to 23″. 

Prevelo Alpha Three Size Range

Three images showing size range of Prevelo Alpha Three - 1) 5-year-old with a 19" inseam. Fits, but long reach makes it uncomfortable. 2) 6-year-old with a 21" inseam. Perfect fit with room for growth. 3) 6-year-old with a 24" inseam. Too small, no room for growth.

Frame Size

Compared to other 20″ bikes, the Prevelo is mid-range in frame size with the Guardian 20″ being taller and the Islabikes BEINN 20″ Small being smaller.  Even though they have similar seat height ranges, our 5-year-old tester was much more comfortable with the shorter reach on the Islabikes BEINN 20″ than the larger Prevelo.

Prevelo 20″ Slightly Big for a 5-year-old in Size 5 Clothes

Comparing frame size of three 20" bikes. 1) Prevelo Alpha Three - long wheelbase for stability with aggressive riding, but creates a long reach for smaller kids. 2) Guardian 6-speed 20": mid-range wheelbase for stability, has shorter reach for smaller kids. 3) Islabikes BEINN 20" Small: Shortest wheelbase (only by 1") provides best reach for smaller kids, does limit stability for aggressive rides.


Gearing & Shifters

The Alpha Three is an 8-speed bike with a gain ratio of 2.1 to 6.7.  This wide range will easily allow kids to tackle hills previously deemed “too hard” as well as quickly gain speed on flat surfaces without having to excessively spin the pedals.

Trigger Shifters vs. Grip Shifters

One of the main differences between the Alpha and other high-end bikes is its use of trigger shifters versus grip shifters.  Trigger shifters are much better for aggressive riders as they generally allow for faster shifting and help riders keep their handlebars straight when riding at faster speeds.  With grip shifters, kids can apply too much force while shifting, which can cause them to accidentally and unexpectedly rotate their handlebars.

Grip shifters (also called twist shifters), however, allow kids’ fingers to remain on the handlebars to shift and only require them to twist up or down to shift. On the flip side, trigger shifters require kids to slightly loosen their grip on the handlebar to shift gears.  Trigger shifters have two buttons – one button for the index finger to shift up and a second button for the thumb to shift down.

While trigger shifters generally take less force to activate, they are less intuitive for kids and have a steep learning curve.  Grip shifters are typically harder to activate but are more intuitive and have an easier learning curve. Prevelo designed this bike for more aggressive riders and/or beginning mountain biking which make trigger shifters the best option for the Alpha.

Trigger Shifter Test Performance

As expected, our 6-year-old tester had some trouble getting started on the trigger shifters, but once he figured it out, he LOVED them.  Already having experience learning the basics of shifting with a grip shifter, the transition to a trigger shifter was relatively easy for him.   Based on our experience, however, learning how to use gears for the first time on a bike with trigger shifters is generally more challenging than on a bike with grip shifters.

Another problem we have encountered in the past with trigger shifters is the child’s ability to reach the two trigger buttons.  Much to our surprise, our smaller-than-average height 6-year-old had no problem extending his index finger or thumb to shift the bike.  Being a more aggressive rider than most kids his age probably factored into his ability to pick this up so quickly. Kids more on the timid side may feel uncomfortable releasing the handlebar grip to shift the trigger shifters.

Our 5-year-old tester, on the other hand, didn’t even attempt to shift the gears as he was already stretched out on the bike and was too anxious to try to shift gears when he couldn’t see the levers.

Trigger Shifters on the Prevelo Alpha Three

Trigger shifter on Prevelo Alpha Three 20" kids' bike - index finger pushes 1st button to shift down, thumb pushes 2nd button to shift up.


The Alpha Three comes with Tektro v-pull brakes.  Quick and effective, the brakes were very responsive when put to the test by our 6-year-old tester.  From making skid marks to slowing down at the bottom of a big hill, the brakes were easy to reach and easy to activate.

As a word of caution, however, the brakes on Prevelo bikes stop much quicker and with more force than lower-end bikes.  So if the Prevelo is your child’s first experience with quality hand brakes, be sure to have them walk next to the bike and practice activating the brakes to get a feel for how much effort is needed to stop the bike – prior to riding the bike.  Kids moving up from lower quality bikes often apply too much force to the brake lever, which causes them to stop faster than anticipated, which can lead to a crash.

Easy-reach Brake Levers on the Prevelo Alpha Three

Tektro v-pull short-reach brake levers - showing short reach and then child easily engaging the brakes.

Prevelo Alpha Three vs. Islabikes BEINN 20″ Small vs. Guardian 20″ Geared

The Prevelo, Islabikes and Guardian are all great bikes that we love, but all three are ideal for different types of riders.

The Prevelo Alpha Three is the most aggressive of these three bikes and is the best for intermediate to advanced riders who are likely to engage in more adventurous riding.  Whether around the neighborhood or on groomed trails, the Alpha Three is superb at allowing kids to really throw their weight around on the bike, while the trigger shifters will help them shift faster and easier.  For true mountain biking, however, the Prevelo Zulu Three (also a 20″) is an ideal choice.

The Islabikes BEINN 20″ Small (also available in Large) is lighter, has a narrower frame, and is best for more timid riders who would benefit from a comfortable, easy-to-ride bike that will gladly take them on extended paved bike rides or even on easier groomed single track trails.  Twist shift gears allow them to easily tackle moderate inclines.

The Guardian 6-speed 20″ is the perfect bike for neighborhood riders, especially those who live or ride around hills where shifting gears and stopping correctly and quickly is essential.  The Guardian is certainly capable of going on longer rides like the others, but its slightly higher weight makes it less appealing.  For the price, however, the Guardian is a great bike for basic all-around riding.

Bottom Line

Christmas came early for our 6-year-old tester, his mom, and even me! We’ve never seen him so happy as when he’s on his Prevelo Alpha Three.  Exceptional from top to bottom, the Prevelo is the ultimate ride for adventurous riders in at least size 6 clothes.

MSRP: $499

By: Natalie Martins

Last Updated: September 7, 2017

FTC Disclosure: No monetary compensation was provided for this review. Prevelo Bikes provided products to Two Wheeling Tots LLC to help facilitate this review. All opinions and images are that of Two Wheeling Tots LLC and should not be used or replicated in any way. Two Wheeling Tots LLC is an affiliate of Prevelo Bikes and all included links to Prevelo are affiliate links.