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

14 Reviews
Zulu Three: In Stock
Zulu Three HEIR: Out of Stock

Wheel Size
20 inches

Approx. Age Range
5½ to 9 years


Trail Optimized

$15 Shipping
in the Continental USA

Shipping Terms

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

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

1% for the Planet
Prevelo donates 1% of sales to planet worthy causes.

The Prevelo Zulu Three packs high performance mountain bike features into a 20-inch wheel size package. Every component is the real deal and is carefully chosen to provide the best performance and fit for young riders ready to tear up the trails. It features:
  1. Prevelo confidence inspiring low and narrow geometry. Prevelo geometry keeps the rider low, balanced and in control.
  2. Zulu specific slack head tube angle and short chain stays keeps the bike controlled over rough terrain.
  3. Lightweight aluminum frame with custom formed 6061 triple- butted tubing and TRAPT™ downtube profile.
  4. Available with a lightweight HEIR® 80mm travel airfork with HM Carbon Fiber / AL6061 lowers & AL7050 hard anodized 30mm stanchions and adjustable rebound, lockout and compression and 15mm Thru-Axle.
  5. Stealth dropper post ready.
  6. Available with tubeless ready wheels and tires.
  7. Rear hub with 12mm Thru-Axle.
  8. Flat mount rear brake caliper keeps the rear brake caliper tucked away and protected between the rear chain stays.
  9. Tektro front and rear hydraulic disc brakes.
  10. Shimano ZEE 10-speed drivetrain. This 10-speed derailleur has a SHIMANO Shadow RD+ Short cage. Because of the small wheel diameter on 20-in bikes, rear derailleurs on 20-inch bikes hang low and close to the ground. The Prevelo Zulu Three uses a high performance short cage derailleurs to keep things high and away from the ground. The derailleur also features a clutch that can be turned on with the flip of a switch to eliminate derailleur bounce over hard terrain and reduce chain drops.
  11. 11-36T wide span gearing gives riders plenty of range to spin up tough hills.
  12. Kid engineered direct mount cranks. All Prevelo cranks are sized specifically for each model bike, down to the millimeter.
  13. 95% assembled. Just install the handlebar, seatpost, frontwheel, and pedals.


zulu three


Customer Reviews

5 Based on 14 Reviews
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Filter Reviews:
    Kerstin K.
    United States

    Excellent Bike - worth the investment

    My son loves this bike! At first he wasn't convinced because it was not his favorite color (red), but after riding a few times on the trails he realized how awesome this bike is. His riding has gotten so much better over the last 2 months. He is finally able to shift gears (his old bike had the revo twist shifters and he could not shift those) and climbing hills without moaning! Major win! Yesterday we took it to a new pump track and he was riding for 3.5 hours straight. This high quality bike is an investment in your little rider, but if you are an avid biker and are taking the kid out on the trail it is a bike that can make them a much stronger rider! If you're thinking about it, take into account how much awesome riding time you'll get with your little shredder and those memories created, not how many years they can ride that size. I absolutely would recommend buying this bike to anyone who is trying to get their kid interested in mountain biking.

    Kerstin K. verified customer review of Zulu ThreeKerstin K. verified customer review of Zulu ThreeKerstin K. verified customer review of Zulu Three
    Pedro G.
    United States United States


    Muy buen servicio y mejores bikes

    Joel U.
    United States United States

    Incredible Zulu Three Heir

    After a great deal of research, I ordered this bike for my 5yo (47”) daughter in late July. It arrived 4 days later to Colorado with custom purple grips. Final assembly of the bike took about 20 minutes. With the addition of purple pedals and a purple water bottle holder, she was grinning from ear to ear and ready to ride. Her first bike was a Huffy Seastar, which was upgraded to an older Diamondback Tess 20. It’s hard to quantify how dramatically her riding has improved in the first two weeks of owning this bike. She has gone from being hesitant on descents of low grade hills to making her first laps on an adult “pump track.” The shifters on this bike allow her to use the full range of gears and she can climb things that were “impossible” only a few days ago. The hydraulic disc brakes and short levers give her confidence to stop in any situation and easy control of the bike. This is an investment. If you have the terrain and you’re thinking about it, do it. Your child will thank you now and later. We can’t wait for the Zulu Four to come out for my 8yo.

    Joel U. verified customer review of Zulu ThreeJoel U. verified customer review of Zulu ThreeJoel U. verified customer review of Zulu Three
    John S.

    Great bike, stand-up customer service & support

    Great bike. I bought my son a Zulu 3 Heir for his 7th birthday. He's always been on good "bike shop" brands (the big S or T), which have been OK, but the fit and design of this bike took his riding up several notches on day 1. The increase in his confidence and ability, simply due to having a better-fitting and kid-specific design has been very noticeable since Ride 1 on the Prevelo. Yes, it's an investment, but if you are passionate about riding yourself and want to help get your future riding partner hooked on the sport, this is a great bike for doing that. Also I would like to give a shout-out to Prevelo's customer service. They made sure to ship the bike quickly (in time for b-day delivery) and also went above-and-beyond to help resolve some minor issues that popped up after delivery. Solid product and solid company, definitely recommend!

    Matt W.
    United States United States

    Stop thinking about it just do it!

    This bike is great. Only down side is my kids are now fighting over it. Time for the z4 too.