The Legion Series represents Mongoose's definitive line of freestyle BMX bikes, crafted for riders progressing from their first drops to elite-level skatepark performance. As the absolute flagship model of the range, the Legion L500 is engineered to dominate the most demanding ramps, quarterpipes, and street gaps, effortlessly absorbing the extreme abuse that advanced riders dish out. Built around a professional-grade, full 4130 Chromoly chassis with a spacious 21-inch top tube, it offers the ultimate combination of structural strength and weight savings. Outfitted with premium additions like a sealed freecoaster rear hub and a halflink chain, it delivers a competition-ready ride straight out of the box.
Key Features
Full 4130 Chromoly Matrix: Frame, fork, and handlebars are all constructed from premium 4130 Chromoly for maximum strength-to-weight performance.
Sealed Rear Freecoaster Hub: Equipped with a pro-spec freecoaster hub that allows you to roll backward smoothly without having to pedal in reverse.
Premium 2-Piece Crankset: Features ultra-stiff 175 mm 2-piece tubular chromoly hollow spindle cranks paired with a 48-spline bottom bracket spindle.
Xposure Infinity-XD Double-Wall Rims: Built with extra-wide, double-wall aluminium rims to prevent wheel buckles during heavy casing or hard landings.
High-Performance Halflink Chain: Utilises a heavy-duty KMC HL1 Halflink chain for precise rear-wheel alignment and maximum drivetrain durability.
Technical Specifications
| Component | Specification |
| Frame | Full 4130 Chromoly, BMX freestyle geometry, tapered headtube, removable brake mounts, mid BB shell, 21" top tube length |
| Fork | 4130 Chromoly, threadless steerer |
| Crankset | 2-piece tubular chromoly hollow spindle, 175 mm, 25T aluminium chainring |
| BB | Mid sealed bearing, 48-spline spindle |
| Chain | KMC HL1 Halflink |
| Cassette | Single-speed, 9T sealed freecoaster driver |
| Brakes | Rear aluminium U-brake and lever |
| Grips | Mongoose, 160 mm |
| Handlebar | Mongoose, 4130 Chromoly, 29" width, 8.75" rise |
| Seatpost | Pivotal, steel, 250 mm, 25.4 mm |
| Saddle | Mongoose Pivotal |
| Headset | Threadless, integrated 1-1/8", cartridge bearing |
| Wheelset | Xposure Infinity-XD aluminium double-wall rims (30 mm ID, 36H); front aluminium sealed-bearing hub (3/8" female axle); rear aluminium sealed-bearing freecoaster hub (14 mm male axle) |
| Tyres | 20" x 2.4", wire bead |
| Extras | Mongoose nylon pedals |
Why this bike is for you
You are an advanced, aggressive, or taller rider (suggested 173 cm / 5'8" and up) who needs a highly resilient 21-inch top tube layout.
You want to learn or perfect complex fakie and woodwork tricks without the restriction of traditional cassette pedalling, thanks to the freecoaster hub.
You refuse to compromise on build quality and want a premium, fully sealed, 100% Chromoly setup that competes directly with custom-built aftermarket rigs.
Why this bike may not be for you
You are a younger or shorter rider who would find the long 21-inch top tube profile too unwieldy and difficult to lift or spin.
You prefer the instantaneous drivetrain engagement of a traditional cassette hub for skatepark lip tricks over the "slack" inherent to freecoaster systems.
For safety reasons bikes can not be shipped partially assembled; they must be fully built and inspected by an authorised technician prior to collection or delivery.




