Mafiabikes Madmain 20” Flat Black Harry Main BMX Bike Review

If you have a budding BMX rider in your home, the Mafiabikes Madmain 20” Flat Black Harry Main BMX Bike is one of the world best bmx bikes for beginners. But before you rush to buy it, it’s best to read this article first to learn everything about it, from its features to its upsides and downsides.

Features and Specifications

The Mafiabikes Madmain 20” Flat Black Harry Main BMX Bike is a budget freestyle BMX bike that’s perfect for younger riders. It features a matte black finish and mint green accent that are simple but attractive.

TIG-Welded Steel Frame and Fork

The material of the frame is steel, which offers strength and shock absorption from landing jumps. All joints are TIG-welded to make the frame stronger and ensure a smooth exterior.

Let’s take a closer look at the different components of the Madmain’s TIG-welded, steel frame and fork.

Top Tube and Chain Stay Lengths

The top tube measures 20.4 inches, which is generally suitable for smaller riders, around 4’8” to 5’4”. The frame uses a short chainstay (13 inches), which moves your weight farther towards the back of the Madmain to keep it agile, playful, and easy to maneuver by beginners.

Head Tube and Seat Tube Angles

With a 75.2-degree angle, the head tube brings the front wheel further away, so the bike is less twitchy. The headset of the head tube is threaded for easier handlebar height adjustment.

Connected to the head tube is a hi-tensile fork. It’s threaded into the head tube (internally threaded fork) to create a clean, sleek look. The classic 71-degree seatpost tube of the Madmain makes sure you can pinch the seat for barspins.

Stand Over Height

The standover height (measured from the ground to the top tube) is 8.5 inches. The short standover height allows beginners to easily practice their spins and manuals.

Front-Load Stem

Attached to the Mafiabikes Madmain 20” Flat Black Harry Main BMX Bike’s threaded steerer tube is a front-load stem. Mafiabikes used the cold forged process to prevent the stem from easily breaking during landings.

Some people think a front loading stem is a bit weaker than a top loading stem. If you feel the same way, there are lots of good-quality freestyle BMX bike with a top loading stem that you could consider, just like the Framed x Spacecraft Twenty9er BMX Bike.

2.4-Inch Fat Bike Tires

The Madmain has the Lagos Crawler tires (20 x 2.4 inches) that fit into strong double-walled rims. These chunky and wide tires can roll fast, without compromising grip. They can handle all types of bumps and hard landings, so young riders can enjoy a softer and more comfortable ride.

25/9 Mafia Steel Gearing

A 25:9 gear ratio (number of times the rear wheel will rotate for each full turn of the crank) gives good clearance, so young riders can do a drop in for the first time. The durable 3-piece cranks are made of chromoly. They’re attached to an 11.5-inch sealed MID bottom bracket that offers a more stable feel at speed.


  • Dimensions: 23.6 x 8.7 x 48.8 inches
  • Weight: 26 pounds
  • Seat: Padded seat with embroidered “MB” logo and integrated alloy post
  • Handlebar: 2-piece, 9 x 29 inches (W x H)
  • Front hub: 10-millimeter loose ball
  • Rear hub: 12-millimeter, semi-sealed with 9T cassette
  • Pedals: Plastic
  • Grips: Hitmain (features a mint green, waffle pattern)

The Good

Not a Heavy BMX Bike

Most people feel comfortable riding BMX bikes weighing around 24.3 to 28.7 pounds (11 to 13 kilograms). As stated above, the Flat Black Harry Main is only 26 pounds. Kids (mainly older ones) won’t have a hard time lifting this or doing stunts on this bike.

Durable Construction

It’s not made of chromoly. However, its double-walled rims, TIG-welded steel frame, chromoly cranks, and other components are strong enough to survive repeated abuse, such as landing on hard surfaces after jumps.

Want a full chromoly frame and fork, check out the PL 26 BMX Race Cruiser—if you don’t mind spending a little more.

Comfortable and Works Well

The top tube is tilted towards the seat tube to allow easy on and off the bike. The extra fat tires absorb a lot of road vibrations and big impacts well. As an entry-level freestyle BMX bike, it does what it’s supposed to do at an affordable price.

Do your flatland BMX tricks with the classic Mafiabikes Madmain 20” Flat Black Harry Main BMX Bike. View the latest deals.


The Bad

Not for Long-Distance Commutes

Well, it is a BMX bike, not a cruiser bike or an off-road bike, just like the Mongoose Dolomite Fat Tire Mountain Bike. The seat of the Madmain isn’t designed for longer rides. It’s narrow and has minimal padding for better energy transfer while pedaling.

It Could be Better

This is an entry-level freestyle BMX bike, so it’s a given that it won’t have the same quality components as a high-end model. The geometry and some components might not fit your riding style or personal preferences (which could have an easy fix).

More Suitable for Kids

The Mafiabikes Madmain 20” Flat Black Harry Main BMX Bike is a kid’s BMX bike. However, that doesn’t mean teenagers or adults can’t use it. As long as you’re not taller than 5’7” or weigh a ton, you could still use this without issues.

Who Is It For?

The Mafiabikes Madmain 20” Flat Black Harry Main BMX Bike is generally suitable for kids (around 6 to 10 years old) in the 5 feet height range. It’s for beginners who are doing more Flatland-influenced tricks because of the frame design. The fat tires make it a suitable choice for people who expect to frequently ride on soft grounds.


The Mafiabikes Madmain 20” Flat Black Harry Main BMX Bike delivers a good performance that exceeds its price tag. In most cases, if there are things that need to be replaced, it’s due to the rider’s personal preferences, not due to quality issues. If you’re looking for a great gift for a young BMX-rider-to-be, this is a good option.

The Mafiabikes Madmain 20” Flat Black Harry Main BMX Bike has the ideal entry-level set-up at an affordable price. View the latest deals.