With the Legion Series, Mongoose offers a full line of freestyle BMX bikes for riders of all ages and ability levels. The Legion L100 was designed to be a fully park, street and dirt worthy BMX bike that offers everything a rider could need from beginner level curb jumps all the way up to advanced aerial tricks on a quarterpipe!


  • Mongoose full 4130 Chromoly frame, tapered headtube, removable brake mounts, and mid BB shell.
  • 175mm 2-piece tubular chromoly hollow spindle cranks with a 25T alloy chainring and mid sealed bearing bottom bracket.
  • 20” x 2.4” tires mounted on wide aluminum double wall 36H rims with 3/8” female axle front hub and 9T cog sealed bearing cassette rear hub.
  • 4130 chromoly handlebar and fork, 50mm stem, threadless sealed integrated headset, and Alloy U-brake.
  • 21-inch top tube length. Suggested rider height is 5'8" and up.

Mongoose Legion L100 Black BMX Bike 2020

  • Wheel Size 20 in
    Frame 4130 chromoly, BMX freestyle geometry, removable brake mounts, integrated headset, mid BB shell
    Fork 4130 chromoly
    Crank 2-piece, tubular chromoly hollow spindle, 25T aluminum chainring
    Chain KMC S1
    Bottom Bracket Mid sealed bearing, 8-spline spindle
    Drivetrain Single-speed, 9T cassette driver
    Rims Xposure Infinity-XD, aluminum double wall, 30 mm ID, 36H
    Front Hub Aluminum, ball bearing, 3/8 in axle, 36H
    Rear Hub Aluminum, sealed-bearing cassette, 14 mm axle, 36H
    Spokes 14G, steel, black
    Tyres 20 in x 2.4 in, wire bead
    Pedals Mongoose, nylon
    Brakes U-brake, aluminum
    Handlebar Mongoose, 4130 chromoly, 29 in width, 8.75 in rise
    Stem Mongoose, threadless top load, 50 mm
    Headset Threadless, integrated 1-1/8", cartridge bearing
    Seat Post Pivotal, steel, 250 mm, 25.4 mm
    Saddle Mongoose Pivotal
    Grips Mongoose MushXL, 160 mm