Hubs are one of the most important parts of your BMX bike, or any bike for that matter. Good quality hubs can make your riding experience a lot better. If you are in need of a new hub or just planning to upgrade, then this guide is for you. Here we have discussed all the things that you need to consider before buying a new set of BMX hubs.
BMX Hub Anatomy
Hubs for BMX bikes consist of four main parts – hub body, axle, bearings, and flanges. The hub body is the main component usually made of aluminium. It houses the axle which passes through the hub body. The axle rests on bearings on either side of the hub and is fixed to the frame/fork dropouts via bolts at each end. The bearings allow smooth rotation of the wheel. Finally, we have the flanges. These are the raised lips on either side of the hub with holes drilled in them for the spokes.
All bike hubs come with one of two types of bearings. The first type, which is the older and cheaper type, is called a cup and cone bearing. You can service them at home, but it can prove to be quite tricky when you handle the loose ball bearings since they are easy to lose. Additionally, adjusting them perfectly after servicing can also be difficult. The second type is called a cartridge bearing. These have sealed ball bearings making them more convenient to service. Moreover, they offer better performance. However, they are also more expensive.
BMX Front Hubs
Nearly all BMX front hubs function in almost the same way regardless of the brand, weight, colour, and size. Their job is simply to roll the wheel forward and backward. Looks, brand, and weight are usually the main factors that affect someone’s decision when buying a front hub. You can divide front hubs into two types according to the kind of axle they have. There are male axles and female axles which are discussed further below. The majority of front hubs will be sold as a set with a corresponding rear hub. This will also influence your choice.
BMX Rear Hubs
The rear hub on a BMX has the same components as a front hub but with an additional mechanism for the drivetrain. According to this BMX rear hubs can be divided into three types – freewheel hubs, cassette hubs, and freecoaster hubs.
A freewheel is a sprocket that is a separate piece from the hub. Hubs using freewheels have a thread where the freewheel can be attached. Freewheel hubs were previously very common, but now cassette and freecoaster hubs have mostly replaced them. They are now only found on older and entry level BMX bikes. Being an external part, a freewheel is limited in terms of how small it can be. The smallest sprocket size is 13 teeth requiring a larger front chainring.
Cassette hubs are the most common rear hub type for BMX. In this type of hub, the sprocket is built onto the drive side of the hub. It also contains a ratchet-and-pawl mechanism that allows you to coast on the bike. The sprocket or “cassette” of these hubs can have as few as 8 teeth. This means that there is less material making them lightweight. If you want to go in reverse with a cassette hub, you will have to pedal backwards.
Freecoaster hubs are a newer design that have quickly become very popular. Just like in a cassette hub, a freecoaster hub also features a built-in ratchet-and-pawl mechanism and a sprocket. However, there is also an internal clutch system that allows you to go backwards without having to pedal backwards. While this may be an advantage, the extra hardware makes freecoaster hubs heavier than cassette hubs.
Axle Types & Standards
BMX hub axles are of two types – male and female. A male axle is a single solid cylinder throughout with threading on either end. Conversely, a female axle is a thicker hollow piece with bolts that thread into it from the outside. Male axles were more common before, but the durability and clean look of female axles have made them more popular nowadays.
BMX axle standards vary from road or MTB axles. The most common size, especially for the rear wheel, is 14 mm. Meanwhile, many front wheels and some racing wheelsets will have a 3/8″ (10 mm) axle. The later size is lightweight but somewhat less sturdy. The size of your frame/fork dropouts will determine your choice of axle size, so check before buying.
A variety of manufacturing processes and materials are used to make BMX hubs. The hub body or shell is usually made of slightly varying types of aluminium alloys, 6061t or 7075 for example. Some models are available in titanium which is lighter. The axles, bolts, and other hardware are typically made of aluminium, steel, or chro-moly, with aluminium being the lightest and chro-moly being the heaviest and most durable.
The weight of a hub can vary from one brand to the other. In general, cassette hubs are lighter with some weighing less than 250 grams since they require fewer materials. On the other hand, freecoaster hubs can weigh up to 700 grams. Front hubs will obviously weigh less than rear hubs due to fewer parts. The materials used and the design also play a role in determining the weight. In the end, the ideal weight comes down to what you want from your bike.
A hub guard is a component found between the hub and the fork/frame of the bike. Its purpose is to protect the hub flanges, spokes, and sprocket. BMX riders often do grinds on ledges and rails and this is why a hub guard is necessary. However, riders who don’t grind will not need a hub guard at all. You should check the compatibility with your hub before purchasing.
The noise that a hub makes while coasting has always been a point of fascination for BMX riders. Some hubs make a clicking noise while some make more of a buzzing noise. Some are louder and some are quieter. The choice is up to your personal preference. Previously, riders would have to adjust the amount of lubricant to get louder or quieter sounds from their hubs. But now, there are enough options available without you having to jeopardize the hub.
Frequently Asked Questions
Q1. How much do BMX hubs cost?
Ans.: The pricing of BMX hubs can vary a lot. Entry level hubs are usually less than $100. On the other end of the spectrum, there are hubs that cost more than $500. The price depends on the build quality, material, hub type, bearing type, etc. Generally, the more you pay, the better performing and longer lasting the hub will be.
Q2. Which is better, freecoaster hub or cassette hub?
Ans.: As stated before, a cassette hub is typically more lightweight. You will have to pedal backwards when reversing with a cassette hub, which a lot of riders actually prefer. However, many of them would prefer to not have to back pedal when going backwards. Hence, they would opt for a freecoaster hub that has the mechanism that allows this. But the same mechanism also makes them noticeably heavier. Ultimately, it’s up to your personal preference.
Q3. What are flip-flop hubs?
Ans.: Flip-flop hubs are normally only found on BMX bikes. They are also called dual-sided hubs. This is because there are sprockets or cogs on both sides of the hub. One side may be threaded to accept a freewheel while the other side may have a built-in cog. This type of hub gives you the option for two speeds, but you will have to flip over the wheel to use the other side. You could use one side for regular, everyday riding. The other side could be used for when you need to ride at higher speeds.
We understand that choosing a new hub for your BMX can be a daunting task. But it is very important to choose the right one since hubs are an integral part of the bike. You should carry out your own research and hopefully, this article has provided enough information. Regardless, the best option would be to visit a nearby store and talk to them to find out exactly what’s suitable for you.