Frames and Forks
The beginner-level freestyle BMX bikes are predominately made up of steel, typically termed as Chromoly 4130 or for a short term named chromo. Hence, the CroMo is alloyed steel that provides reliable strengthening properties. However, some cheap and low-end store bikes offer ‘Hi-tensile’ steel.
The chrome steel is ‘butted’ that typically thinner and lighter. Hence, this thin and lightweight material is used for tubing and reinforcement around the ends that give strength to your bike.
Generally, steel is the standard material for bikes as it can give a high resistance to fatigue. Moreover, this is a comfortable material that could repair and offer some additional compliances such as comfort. Furthermore, steel adds ease while reducing the pressure on the rider’s body.
For BMX racing, the preference is to hold lightweight frames and stiffer them. These race bikes are made of Aluminum as a choice of material. However, if you are those who love racing and want some extra edge feature, then go for frames made up of carbon fiber since these frames are getting high popularity among the ‘Elite BMX race bikes’ by reducing the extra weight even further. Also, it has the additional feature of dampening the vibration. You cannot find this property in Aluminum and Steel.
The freestyle BMX bikes are relatively preferred by kids, teenagers, and adults. Hence, the size of the wheel stays consistent in all freestyle bikes. However, the frame size of these bikes might change. These frame sizes are subtly based on the rider’s height and riding style. In the market, you will mostly find the freestyle bikes that are available within 21″ top tubes. This standard size is ideal for the rider to have enough space to swing their BMX bike underneath them, especially when performing any trick. So if you are among such categories who love to display their skills and tricks such as airborne tricks, then we suggest going for 21-inch frame size. Moreover, this frame size with the short seat combination will also provide ease to whip around the corners freely.
For the flatland bike riders, the frames typically have the only expectations that require lightweight and a short tube around all over. This type of structure is used for balancing and controlling the bikes. Moreover, they also have much steeper head angles and 3/8″ dropouts for small rear axles.
On Race bikes, a longer wheelbase and slacker head angle put the riders quite further back on the bike. This feature allows the riders to improve their stability while handling the speed. Moreover, the race bike frame size always comes in a variety of broader ranges that suit the rider spread on the age level.
Typically the standard size for a BMX wheel is 20 inches. This wheel size is relatively smaller than the other mountain or road bikes. Interestingly, you will even find even smaller wheels on the kids’ BMX bikes around 16 to 18 inches in size. However, if you are doing dirt jumping, then BMX bikes also provide extensive wheel options for you. The estimated length for larger wheels is between 20 to 24 inches wheel. These wheel sizes can mostly be seen on some ‘trail’ BMX bikes for the people who want to stand out during showcasing their jumping skills.
If you are looking for BMX wheels for your racing arena, you will realize two subcategories of wheel size. Hence, the most common category for the wheels is 20 inch and the second one is a cruiser, which is 24 inches. Typically the cruiser bikes are popular among old or tall riders. This 24-inch cruiser wheel provides efficient stability to the riders.
Generally, BMX freestyle racing always demands a lightweight, quick acceleration out of the starting gates. Hence, wheels for such freestyle BMX racing should be even lighter in size.
The standard rim width for a freestyle BMX bike is 32 mm. Hence, for the riders who expect to have a few more hard hits in the wheels, always choose the more comprehensive rim option. So, the width size of the rims is 36mm wide. Typically, the rims are made up of Aluminum material, which can be walled into single, double, or triple. Since the addition of more metal layers will eventually provide more structural support. However, this addition of walled layers will lead to an increase in the penalty of weight. For the majority of the BMX riders, the ideal standard walled layer is double-wall. This classic wall can bring the right balance of weight and strength to BMX bikes.
For the advanced skill level, BMX riders who want to put some extra demand on their equipment always go through customization. They prefer to choose the wheels that have been built-up aftermarket precisely based on their suitable requirements. Moreover, they are more selective in selecting the rims and spoke counts.
While choosing any BMX bike or buying your new BMX wheel, the most important thing to consider is the spokes count. Typically, the spokes are ‘laced’ from the hub point to the rim and stay strong and true, and they rely on tension. The strength and weight of the complete wheel are directly associated with the number of spokes. Generally, a 36 spoke wheel would satisfy most riders who prefer to do freestyle BMX bikes. However, for more advanced skill level riders or the heavier riders, go for the wheel spoke up to 48. The material used to create the spoke is steel wire, and the amount of thickness for each spoke wire throughout the way is the same. However, if you encounter something that referred to as ‘butted’ spokes, similar to butted frames, you might see the spokes that are thinner at the middle portion and are thicker at the end. These butted spokes bring additional strength to the wheel while reducing the weight.
The spoke count for BMX wheels will lie somewhere between 28 to 36 spokes. Moreover, to shave the possible weight for freestyle BMX bikes, the spokes are engineered with alloy rims.
The tires are considered the first point of contact at any riding surface. So, when you ride your BMX bike, the choice of your tire will directly affect the handling, grip, and speed or rolling resistance. For the park and street riding surface, the preferable tires are smooth-rolling and broader. Hence, the premium quality BMX tires can accept pressures up to 110 psi. This tire can roll faster than a low inflated tire and will also protect the rim during under load after a hard landing.
Other surfaces such as dirt jumping will need something more tread for traction on the dirt. Hence, the quality of tires for these surfaces must hold low pressure to ensure a better grip. So, wider than race tires, go for something 20-inch x 2.1 to increase the excellent stability and more surface area. The best part of tires is they can easily change and swapped. This property enables the riders to choose and change the tires to satisfy their needs.
For BMX racing, the tires are relatively narrower that perfectly suited with the slimmer rim profile. This way, it will reduce the weight and help the rider roll faster on the racing track.
Hubs are the centerpiece of a wheel. Typically BMX hubs are the powerhouse of the bike filled with bearings that helps the wheel to spin. Usually, the hubs are made up of alloy. Hence, the wheelsets or bikes at a low price can feature open-cage ball bearings. Although this is relatively cost-effective, they are usually more susceptible to damage and are considered less durable. On the other hand, sealed or cartridge bearings are reliable, protect the hub but cost you some extra bucks.
Usually, the cartridge bearing has small steel balls that keep the unit sealed and make it protected from contaminated debris and dirt. Hence, choosing BMX bikes or wheelsets with sealed cartridge bearings will eventually bring reliability to the ride. The standard BMX axle size is estimated as 14mm. With the flatland BMX bikes, options lie for 3/8inch or 10mm axles to save weight. Hence, the axle properly fits through the center of the hub and slightly slides into the dropouts to maintain the weight’s proper placement. These hubs are fastened tight with the bolts.
Hence, the BMX hubs are of four different types which are:
One might hear such words sprocket and chain-ring interchange when talking about gear. To make things easily understandable for you, the chain-ring is the front ring attached to the crank, and the sprocket is termed as the rear driver, which is connected to the hub.
Though, the BMX bikes do not have a combination of multiple gears. However, the BMX bike has a ‘gear ratio,’ the number of teeth on the chain-ring, and sprocket, and ideal pairing. To learn more in-depth about gear ratio, one might need to dig deeper into basic mathematics. For simple formula diving, the number of teeth on the chain-ring by the number on the sprocket will give you the rear wheel rotation for every chain-ring. Hence, the low number will provide ease to the pedal, and a high number will make it difficult to pedal.
Regardless of the traditional and race BMX, the freestyle BMX has the combination of smaller chain-ring/sprocket to ride out the tricks and bring better clearance features. Their typical gear ratio is 25/9 that referred to as the ratio of chain-ring/sprocket, respectively. This enables the freestyle BMX to take less effort to accelerate into the jump or trick quickly. However, with this ratio, the rider has to compromise on power and speed.
Since the BMX racers need to choose while changing gear ratio to match the rhythm and fulfill the demand of different racing tracks, the racers simply select them based on their ability level and physiology. When you are looking to purchase, make sure it is safe to trust the race bike gears that are roughly 55 gear inch and can be suited for most of the riders.
Typically, cranks can be bought in one, two, and three-unit pieces.
- The single-piece crank has right and left crank arms and spindle as one steel piece. The arms are relatively thinner and more flimsy. Mostly you can find them in cheap BMX or kids bikes.
- In a two-piece crank configuration, the spindle is fixed with one crank arm, and the other one stays separate. These cranks have a thicker tendency and are sturdier.
- Three-piece cranks are the stronger ones and have the capacity of both spindles and crank arms in all of the three different units.
Ideally, it is an excellent choice to go for two or three-piece cranks made of Chromoly to enhance the durability and strength of your BMX bikes. The length of the cranks may be varied from 145 to 190mm. Although the freestyle riders mostly prefer short cranks that allow for clearance while they are performing tricks. Their common choice lies somewhere in 165mm. For the race, the BMX crank size is dependent upon the height of the rider. And sometimes, they are made up of Aluminum that can decrease weight.
The BMX pedals preferred choice for all types of BMX freestyle bikes can be wide platform plastic that can reduce weight. These plastic pedals are relatively inexpensive, and the bonus part is they are less harsh than other types of metal pedals. The pedal axle for the BMX bikes is 9/16inches on two or three-piece cranks along with half-inch one-piece cranks. It is critically important that one must know the size of the pedal while buying the new one.
The preference for doing racing should use clip-in-pedals or SPD as these riders enable the riders to have the ability to maximize the power and get the speed as the gate drops. However, if you are at the beginner level of using BMX bikes, then picking a flat pedal will be sufficient. This flat pedal will smoothly bring confidence to handle the bike, and the gate starts.
The saddles or BMX Seats don’t play many roles while setting up your BMX bikes. This enables the low preference for the harnesses. At the entry or beginner level for BMX bikes, one has a bit more cushions along with a large surface to gain the assumption that the rider can easily sit down and can pedal more. However, at an advanced level, the ride mostly floats above the saddle a lot.
These are the types of saddles:
- Integrated seat/Seatpost
- Pivotal saddles
For the freestyle BMX, the handlebars rise a bit steeper than other BMX race bars. This help freestyle BMX to maneuvered better. Typically, these BMX handlebars are made with popular materials such as Aluminum and Chromoly, and the latter are lighter. However, these materials might bring more susceptibility to fatigue, and using other materials such as steel will carry more weight. However, steel dampens the vibration and can be last for a longer time.
Generally, the handlebars can be found in 24inch BMX bikes that may not have the crossbar’s property. This size has also significantly held less raise to account for the higher stack due to bigger wheels and larger frames.
When talking about flatland handlebars, they usually have a very minimal sweep. So the bars can feel the same while shifting backward or forward. They also bring a low crossbar so the rider can smoothly swing their legs over while doing tricks.
Typically the BMX bikes have the rim-brakes feature. Here the pads are connected to the rim that can slow down the momentum. The freestyle bikes are usually equipped with U-brake that can sit inside the rear triangle. Most freestyle bikes can come up with a “Gyro” or “detangler” braking system for handling the rear brake.
Distinguishable through the division of two cables nearby the mechanism that fitted around the headtubes, the detangler will allow the bar to spin full 360 degrees without getting tangled into the brake cables. This way, it will bring incredible help to advance the tricks, likewise tailwhips and barspins. If these tricks are not part of your radar, you can go for standard brakes.
However, the front brake will allow in the racing. It is not critically important for the racers opting for the linear-pull and secure rear brake. This is also known as V-Brake.
Hi, I’m Mike, working as a content strategist at BMX Brand Guide. I’m in love with BMX since childhood when my parents bought me a bicycle. Since then, I have been exploring them and is a first-hand witness of how BMX has evolved. I have been sharing my expertise and knowledge with the public through this site.