Specialized 21 Riprock Coaster 12


With our Riprock Coaster 12, riding gets boiled down to its simplest element—fun. And to make sure of it, we designed the bike with tons of cool features that are easy for your little ones to use, like a coaster brake for simple stopping, wide 12x2.3" tires that increase stability and confidence, and tough components that will stand up to years of abuse. It's the perfect bike for your little ripper to start getting out on the trail with—we just wish that we had one when we were kids.


  • The A1 premium aluminum frame is lightweight and built to withstand the tough use by kids, while the geometry features an ultra-low standover that makes it easy for your little ones to fit on and grow with the bike.
  • Steel coaster brake is a reliable, easy to use brake perfect for safe stops and awesome skids.
  • 12x2.3" Rhythm Lite tires deliver tons of traction, comfort, stability, and fun over all types of terrain.




FRAME - Specialized A1 Premium Aluminum
FORK - Hi-Ten, 1" threaded steerer
FRONT HUB - Bolt-on, 95mm spacing, loose ball bearings, 16h
REAR HUB - Coaster brake, bolt-on, loose ball bearings, 110mm spacing, 16T cog, 16h
SPOKES - Stainless, 14g
RIMS - 12" alloy, 16mm depth, 21mm internal width
FRONT TYRE - Rhythm Lite, 30 TPI, wire bead, 12x2.3"
REAR TYRE - Rhythm Lite, 30 TPI, wire bead, 12x2.3"
CRANKSET - Hi-Ten steel, 76mm
BOTTOM BRACKET - Steel, loose ball bearings
CASSETTE - 16T cog
CHAIN - KMC Z510, single-speed, anti-drop, 1/2"x1/8"
FRONT BRAKE - V-brake w/ tool-less reach adjust brake lever
REAR BRAKE - Coaster brake
HANDLEBARS - BMX, steel, 10-degree backsweep, 4-degree upsweep, 65mm rise, 470mm width, 22.2mm
GRIPS - Specialized, slip-on
SADDLE - Specialized Kids'
SEATPOST - Steel, 22.2mm
SEAT BINDER - Bolt-type, 28.6mm
PEDALS - Nylon platform w/ reflectors