Mongoose Legion L40

Mongooses Legion L40 is the sweet-spot BMX in the range. Its extremely good value for riders – especially for teens and pre-teens – who are often searching for their first proper BMX.

Mongoose has used a high-tensile (or Hi-Ten) steel for the main frame and fork. A high-tensile steel is used for the Legion L40 because its part of a group of performance steels. This means better corrosion resistance, lighter and can handle way more stress.

The Legion L40 frame has a 20.5-inch top tube.

Its worth noting that all Legion BMXs (except for the L16 and L18) have 20-inch wheels. Its the OG wheel size; present since Day 0.

The models differ in the components – and the top tube length.

And the top tube length is (one of) the things that matter. Its how long or short a BMX is. 20.5-inches is a good average size. As a rough estimate, wed recommend the 20.5 top tube for riders between 152cm to 168cm.

Yes, BMXs are simple (especially compared to a mountain bike) but parts for key areas still needs to be thought about.

One area is the bottom bracket.

Its under tremendous load – always. Its where you apply pressure to the pedal and where you apply power.

The Legion L40s mid-sealed bottom bracket features sealed bearings. These are going to be resistant to the elements and therefore last longer, especially compared to the bottom brackets on the Legion L10 and Legion L20.

Rims tend to be the other area.

The L40 build uses a 36-hole wheel for extra strength. Plus the rims 24mm width paired to 2.30-inch wide tyres means it can handle impacts and has less chance of pinch flatting. The wide rim also adds extra strength.

Upgrade from Legion L20

• 0.25-inch longer in the top tube (20.5 top tube).
• Better Mid-sealed bottom bracket (details below).
  

Key Features

• 20.5 top tube length. Suggested rider height is 152cm-168cm.
• Hi-Ten steel frame and mid BB shell.
• Drivetrain features 175 mm 3-piece tubular chromoly hollow spindle cranks with a 25T steel chainring and mid sealed bearing bottom bracket.
• 20 x 2.3 tyres mounted on aluminium single wall 36H rims with 3/8 in axle front hub and 9T cog sealed bearing cassette rear hub.
• Hi-Ten steel handlebar and fork, 50 mm stem, standard 1-1/8 headset, and aluminium U-brake and brake levers.
  

SPECIFICATIONS

Size 20.50-inch Top Tube Frame Hi-Ten steel, BMX freestyle geometry, mid BB shell Fork Hi-Ten steel steerer and fork Crank 3-piece, tubular chromoly, 25T steel chainring Chain KMC S1 Bottom Bracket Mid sealed bearing, 8-spline spindle Cassette Single-speed, 9T cassette driver Rims Aluminium single wall, 24mm ID, 36H Hubs [F] Steel, ball bearing, 3/8″ axle, 36H [R] Steel, sealed-bearing cassette, 14mm axle, 36H Spokes 14G, steel, black Tyres 20″x2.30″, wire bead Pedals Mongoose, nylons Brakes U-brake, aluminium Handlebar Hi-Ten steel, 28″ width, 8″ rise Stem Mongoose, threadless top load, 50mm Headset Threadless, integrated 1-1/8, cartridge bearing Seat Post Steel, 250mm, 25.4mm Saddle Mongoose Unifier Grips Mongoose Mush XL, 160mm