Size Guide

Prevelo Bike Sizing

Getting your kids the right size bike is important and, fortunately, also easy. You just need two pieces of information about your little rider:

  • Inseam
  • Rider Experience

Measuring Inseam

  1. Have the rider stand against a wall, hold a book between their legs so that it is firmly against their crotch (the same place their bicycle seat will be).
  2. Measure the distance from the floor to the top of the book.

Rider Experience

Children who are learning are more sensitive to bicycle height than children who already know how to ride a bike. For this reason, our recommendations for bicycle sizing vary slightly based on the experience lever of the rider. The chart below takes into account the fact that experienced riders tend to adapt better to a bike that is slightly larger. For this purpose we categorize young riders as either "Learners" or "Pedalers"

  • Learner: riders who either have not yet learned to ride a pedal bike, or are still frequently putting their feet on the ground while riding.
  • Pedaler: riders who can ride confidently and only put their feet down to stop.
Model Wheel
Approx. Rider Age
Learner Inseam
Pedaler Inseam
Alpha Zero 12" 1½ + 12.5 to 16.5
Alpha One 14" 3 to 5 13.5 to 16.5 13 to 16.5
Alpha Two 16" 4 to 6 16.5 to 22
15 to 22 
Alpha Three 20" 5 to 9 20 to 23 17.5 to 23
Alpha Four 24" 7 to 11 24.5 to 28 23 to 28
Zulu Three 20" 5½ to 9 22 to 26 20 to 25
Zulu Four 24" 8 to 11 25 to 29 23 to 29
Speed Silver
Power Purple


Wheel Size
16 inches

Approx. Age Range
4 to 6 years


Fast and Free Shipping

Shipping Terms

Checked and Tuned
Each bike is checked & tuned prior to shipment.

Easy Assembly
Includes all the tools you need & easy instructions.

  • The 16" Alpha Two is the perfect bike for 4 to 6 year olds whether they are just learning to ride or are mastering the trails. It features:
    1. Ships with a bonus short seat post for additional height adjustment.  A short seat post and the tool required to change seat post are included!
    2. Prevelo confidence inspiring low and narrow geometry. Prevelo geometry keeps the rider low, balanced and in control
    3. Lightweight 6061 aluminum frame with custom formed tubing.
    4. Lightweight aluminum alloy fork with chromoly steerer.
    5. Tektro front and rear v-brakes with small reach brake levers.
    6. Front and rear hubs with low profile rounded hex bolts and no harsh edged nuts for little legs to knock against.
    7. Three piece crank with squared taper cartridge bearing bottom bracket and ultra narrow Q factor.
    8. Double chain wheel guard.
    9. Custom made cranks. All Prevelo cranks are sized specifically for each model bike, down to the millimeter.
    10. 95% assembled. Just install the handlebar, seatpost and pedals.
  • Specifications

    Weight (including pedals) 14.5 lbs / 6.6 kg
    Minimum Saddle Height 17.7 in / 450 mm*
    Maximum Saddle Height 25.0 in / 635 mm
    Bottom Bracket Height 7.2 in / 182 mm
    Gain Ratio 3.8
    *The Alpha Two includes a bonus short seat post that allows the saddle height to be lowered to 17.7 inches.
    Standard 300mm seat post height range: 21 in (535 mm) to 25 in (640 mm) 
    Short 200mm seat post height range: 17.7 in (450 mm) to 21 in (535 mm)


    A Wheel Size 16"
    B Wheelbase 28.8 in / 730 mm
    C Effective Top Tube Length 15.4 in / 391 mm
    D Head Angle 69°
    E Seat Tube Angle 69°
    F Chain Stay Length 12.1 in / 307 mm
  • Components

    FRAME 6061 heat treated aluminum alloy custom formed tubing
    FORK Aluminum alloy blades with chromoly steerer tube - 35mm rake
    SEAT CLAMP Aluminum alloy with toolless adjustment
    FRONT BRAKE Tektro aluminum V-brake
    REAR BRAKE Tektro aluminum V-brake
    FRONT BRAKE LEVER Tektro aluminum short reach
    REAR BRAKE LEVER Tektro aluminum short reach
    CRANK SET Prevelo anodized alloy 3-piece square taper with 95MM crank length.
    SPROCKET 25T with double chain ring guard
    BB SET Sealed cartridge
    HEAD SET 1 1/8" threadless
    RIM Aluminum with grinded sidewalls
    FRONT HUB Lightweight alloy 1-piece forged CNC with low profile rounded hex bolts
    REAR HUB Lightweight alloy 1-piece forged CNC with low profile rounded hex bolts - 14T cog freewheel
    TIRE & TUBE Kenda Small Block Eight Pro 16 ×1.5
    SADDLE Prevelo small kid saddle
    HANDLEBAR Prevelo Aluminum - 470mm wide x 50mm rise - 22.2mm to 19mm taper
    HANDLEBAR STEM Aluminum 30mm extension
    GRIP Kraton rubber
    PEDAL Composite with 9/16 chromoly axle
  • Kickstand

        • Custom sized for the Prevelo Alpha Two
        • If you order a kickstand with a bike, it will come installed on the bike
        • Lightweight aluminium alloy
        • Non-corrosive, solid non-porous casting
        • Dual spring pressure plate and snap action mechanism with hardened steel pivot pin
        • Non-slip clamping surface
        • Made in USA


    Custom Color Grips

    Customize your new Prevelo with grips in the rider's favorite color. Made for Prevelo out of 100% silicone by ESI in Southern California.  We will install the grips on your Alpha Two before shipping.

    custom grip colorsprevelo bike custom grip color


    Rider Name Lettering

    • Custom cut out of 2.5 mil vinyl right here at Prevelo HQ in California and applied to BOTH seatstays before shipment.
    • With a bit of work the decal can be removed when it comes time to hand the bike down.



What the bicycle media is saying

two wheeling tots logo


Slick, fun, and fast, the Prevelo Alpha Two 16″ kid’s bike will quickly turn any child into a bike enthusiast.

rascal rides logo

You can’t get a nicer 16″ pedal bike

A big thumbs up


Kid Centric Features

Kid Engineered Crank

Rounded Axle Bolts

Internally Routed Cables

Kid Size Hand Brakes



Sealed Bearings

Quick Adjust Seat Height

Built Kid Tough

Confidence Inspiring Geometry




Customer Reviews

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  • Reviews (69)

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United States

Alpha Two for my 4 year old - He loves it!!

At 2.5 we got my son a balance bike, and by 4 he was a REALLY solid rider. We knew it was time for his first pedal bike. I wanted to make sure that we got him something that was well made and purpose built for someone his size so he'd have a smooth transition. Fortunately I found Prevelo! We gave my son his Alpha Two on July 4th and he took off immediately!! For the last 2 weeks he's been crushing it. Below are my favorite things about the bike: - Beautiful frame with quality welds - Quality components (Tekro brakes and Kenda tires) - Mid-range gain ratio; high enough to allow him to pickup the speed he needs on the flats but also low enough that he can pedal up hills - Front and rear hand brakes (no coaster break) My son is 41" tall, has a 16" inseam, and weighs 35.4 lbs. He was at the upper end of the 14" Alpha One and the lower end of the 16" Alpha Two. Based on feedback from Jacob at Prevelo I went with the Alpha Two. That model includes a shorter seat post. We are currently using that and my son can get his feet on the ground with no issue. He should have plenty of room to grow! Jacob (owner) was extremely nice and answered all of my questions via email...even spent some time with me on the phone. If you are looking for a quality bike for your child that will last, AND you want to support a family-owned, US-based business, please consider Prevelo.

Anonymous verified customer review of Alpha Two
Dennis A.
United States

What an amazing choice

After making a mistake and buying my son $200 Trek with coaster brake and adult sized trips, I started looking for better bike for my young racer. Originally I was going to get a model with 14" wheels. My little guy just turned 3, and he is quite small. However he is very athletic, with good balance and decent bike handling skills ( started on a Strider, followed by Trek mentioned above and Stacyc electric bike). So I decided to take a chance and get this model. I am extremely glad that I did. Within a couple of hours my hooligan was riding circles around me and was starting to use both brakes. Bike came well packaged, with optional bell already installed. Everything was adjusted properly so assembly was a pain free. I'm very impressed with this bike. Fit and finish is excellent and tiny grips are super comfortable for little hands. So far the bike held up fine in a couple of gnarly crashes.

Dennis A. verified customer review of Alpha Two
Andrea S.
United States

Amazing bike!

This bike is phenomenal! My five year old son loves it and rides it for hours every day. He tells me it's his favorite thing he has ever had. The Alpha Two is lightweight so it's easy for him to ride uphill and easy for me to carry upstairs to our apartment or on the subway. It was easy to assemble, the quality is excellent, and it encourages a really nice position when riding. Nothing but great things to say about this bike and the wonderful people at Prevelo.

Rita L.
United States


Our 5 yr old son is on the small side, and because of the included shorter seat post and amazing geometry, he comfortably learned to ride his first pedal bike in about 30 minutes! A positive experience of confidence, joy and pride is what we had hoped for when choosing this bike, and we thank you for creating an amazing bike that gave him exactly that and more. He had been riding a balance bike since he was 3 yrs old, but still we did not imagine he would be riding on his own like this so quickly. It really is thanks to the design of this bike. By the next day, he started kicking off on his own to start riding smoothly…no wobbling! We were floored. Thank you Prevelo for making such an amazing bike! Our son is in love with his bike with “Big Wheels" and we have loved every moment of him learning and now riding his first pedal bike.

maria c.
United States

Couldn't be happier!

It was everything I was expecting! My 3.5 yr old with 47" inseam could get on the bike and feel secure by reaching the ground with his feet. Coming from a balance bike, this was a must but no other commercial bike has its seat low enough! He learned, by himself, in his second attempt. I was drooling proud. The bike quality is outstanding. Seriously considering a second child for them to use it. Just kidding here. Thanks a lot!!!

maria c. verified customer review of Alpha Two