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Precaliber 20 Boy's

$329.99 Model 21887

Precaliber 20 SS will have your little rider begging to go out for a pedal on their first "real" big kid bike. It's a great transition bike, with a hand brake and singlespeed gearing, plus a strong and sturdy frame and components that are dialed to fit your kids now, and easy to adjust when they grow. For kids ages 6-8, between 3'9.5˝ - 4'4.5˝ tall.

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It's right for you if...

Your kid has outgrown their old bike, and you want to get them a fun, durable bike that they won't outgrow right away. You don't want to settle for a big box brand, and want a high-quality bike that will keep your kid confident and in control so you don't have to worry. 

The tech you get

Your child will ride confidently with a sturdy Alpha Silver Aluminum frame and dialed components that were designed to better fit kids—an adjustable bar and stem, smaller-diameter grips, a padded adjustable saddle, smaller pedals. Plus, dialed singlespeed gearing that's not too hard or too easy to pedal, and rear coaster brakes with a hand brake for instinctive stopping. 

The final word

This bike is the perfect choice for young riders who want to transition from a little kid bike to a big kid bike, with a simple, quality frame that will keep them upright and smiling while they ride at the park with friends or on the local bike paths with your family. 

favorite_borderWhy you'll love it

  1. Precaliber introduces young riders to a lifetime of cycling, which means a healthier, more environmentally friendly future
  2. We all know kids grow up fast, and our adjustable Dialed Fit system allows this bike to grow with them so you don't constantly need to trade up a size
  3. Trek's legacy is one of safety, quality, and fun, so you can have peace of mind that big box brands don't offer
  4. Growing up is better with bikes 



  • Frameset

    20˝ Dialed frame size, Alpha Silver aluminum
    Dialed 20˝, high-tensile steel
  • Wheels

    Front hub
    Rear hub
    Coaster brake
    20˝ 32-hole alloy
    Bontrager Dialed 20x1.80˝
  • Drivetrain

    Dialed adjustable length 120mm - 140mm, 32T
    Bottom bracket
    Sealed cartridge
    19T cog
    Dialed 9/16˝, platform
  • Components

    Dialed 20˝ size, padded
    Steel, 27.2mm
    Dialed 20˝ size, 90mm rise
    Dialed, Kraton
    Dialed, alloy
    Head set
    Adjustable ball bearing, threadless
    Brake set
    Alloy linear-pull w/Dialed alloy levers and coaster brake rear hub
  • Weight

    10.82 kg / 23.85 lbs
    Weight limit
    This bike has a maximum total weight limit (combined weight of bicycle, rider,and cargo) of 36 kg (80 lb).
We reserve the right to make changes to the product information contained on this site at any time without notice, including with respect to equipment, specifications, models, colors, and materials.
Bike and frame weights are based off Trek pre-production painted frames at time of publication. Weights may vary in final production.

Sizing & fit

Proper bike fit is essential for best performance and comfort. Any size and geometry measurements shown on trekbikes.com are for general comparison purposes only. To find your perfect fit, visit an authorized Trek retailer, where an expert skilled at sizing will help you find the appropriate bike and size for your individual needs.


Rider Height

All measurements provided in cm unless otherwise stated.

Wheel size A — Seat tube B — Seat tube angle C — Head tube length D — Head angle E — Effective top tube G — Bottom bracket drop H — Chainstay length I — Offset J — Trail K — Wheelbase L — Standover M — Frame reach N — Frame stack Saddle rail height minimum (w/short mast) Saddle rail height maximum (w/tall mast)
20" kids' 25.5 72.0° 10.5 70.0° 44.5 1.5 37.2 4.2 4.8 87.3 46.9 30.6 42.9 59 73.5

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