Alpha Four

Size Guide
Sizing

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
Size
Approx. Rider Age
(years)
Learner Inseam
(inches)
Pedaler Inseam
(inches)
Alpha Zero 12" 1½ + 9.5 to 13.5
Alpha One 14" 2½ to 4½ 12.5 to 16 12.5 to 16
Alpha Two 16" 3½ to 6 16 to 18 with short seat post
(21.5 to 24 with long seat post)
15 to 17.5 with short seat post
(20.5 to 23.5 with long seat post)
Alpha Three 20" 5 to 9 18 to 23 17.5 to 22.5
Alpha Four 24" 7 to 11 24 to 29 23 to 28
Zulu Three 20" 5½ to 9 21 to 26 20 to 25
Zulu Four 24" 8 to 11 24 to 29 23 to 29

Wheel Size: 24 inches
Approx. Age Range: 7 to 11 years
In Stock - Ships Free and Fast!

24-Inch Wheels | V-brakes | 8-Speed

  • The 24" Alpha Four offers an 8-speed Shimano drive train. The 11-34T wide range gearing is the real deal and gives growing riders truly usable gear range. It features:
    1. Prevelo confidence inspiring low and narrow geometry. Prevelo geometry keeps the rider low, balanced and in control.
    2. Lightweight 6061 aluminum frame with custom formed tubing.
    3. Lightweight aluminum alloy fork with chromoly steerer.
    4. Tektro front and rear v-brakes.
    5. Quick release front and rear wheels for toolless wheel removal.
    6. Three piece crank with squared taper bottom cartridge bearing bottom bracket and ultra narrow Q factor.
    7. Custom made cranks. All Prevelo cranks are sized specifically for each model bike, down to the millimeter.
    8. Shimano ALTUS 8-speed drivetrain. This 8-speed derailleur has a SHIMANO Smart cage. This unique pulley cage permits the use of a shorter pulley cage without comprising gear ratio width. Because kids’ bikes have small wheel diameters, rear derailleurs on kids bikes hang low and close to the ground. The Prevelo Alpha bikes use Smart cage derailleurs to keep things high and away from the ground.
    9. Shimano ACERA RAPIDFIRE Plus Shift Lever. Small hands have a hard time using twist shifters. We use reliable silky smooth thumb shifters. They are easy for small hands to operate, have an indicator display, and operate just like shifters on high performance bikes.
    10. Replaceable derailleur hanger. If the derailleur takes a hard hit, the hanger can be replaced without repair to the frame.
    11. 11-34T wide span gearing gives riders plenty of range to spin up tough hills.
    12. 95% assembled. Just install the handlebar, seatpost, front wheel and pedals.
  • MEASUREMENT SPECIFICATION
    Weight (including pedals) 21.2 lbs / 9.6 kg
    Minimum Saddle Height 25.8 in / 655 mm
    Maximum Saddle Height 31.2 in / 792 mm
    Bottom Bracket Height 9.9 in / 252 mm
  • Trying to decide between the Alpha Four and the Zulu Four? Click here to learn the difference:   Alpha Series vs. Zulu Series

What the bicycle media is saying

With his first ride on the Prevelo...our tester was in love.

- Two Wheeling Tots

Components

COMPONENT SPECIFICATION
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 alloy V-brake
REAR BRAKE Tektro aluminum alloy V-brake
FRONT BRAKE LEVER Tektro aluminum alloy
REAR DERAILLEUR 8-speed Shimano Altus double servo with Smart cage
SHIFTER REAR Shimano Acera RAPIDFIRE Plus
FREEWHEEL/CASSETTE Shimano 11-34T
CRANK SET Prevelo anodized alloy 3-piece square taper with 130MM crank length.
SPROCKET 32T 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 quick release
REAR HUB Lightweight alloy 1-piece forged CNC with quick release
TIRE & TUBE Kenda Small Block Eight Pro 24 ×1.5
SADDLE Prevelo big kid saddle
HANDLEBAR Prevelo aluminum big bore - 580mm width x 40mm rise with 31.8mm to 22mm taper
HANDLEBAR STEM Aluminum 60mm extension
GRIP Kraton rubber
PEDAL Composite with 9/16 chromoly axle

Geometry


MEASUREMENT SPECIFICATION
A Wheel Size 24"
B Wheelbase 38.1 in / 968 mm
C Effective Top Tube Length 19.6 in / 498 mm
D Head Angle 69.
E Seat Tube Angle 69°
F Chain Stay Length 16.3 in / 415 mm

Customer Reviews

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