BMX Wheels Explained

BMX Wheel Quick Guide

Cassette: Positive engagement when pedalling, with the cranks rotating backwards during fakies.
Freecoaster: Allows you to roll backwards without the cranks automatically rotating backwards.
Planetary freecoaster: A different freecoaster system that gives a more cassette-like feel with very little traditional freecoaster slack.
RHD / LHD: Right Hand Drive or Left Hand Drive.
Driver: The small rear cog on the hub, commonly 9T on modern freestyle BMX bikes.
ERD: Effective Rim Diameter – one of the measurements needed to calculate spoke length.
36H: 36 hole – the most common modern BMX hub and rim spoke count.
48H: 48 hole – less common today but still used, particularly for heavy street riding where wheel strength is prioritised over weight.

Complete BMX Wheels

A complete wheel comes already built with the hub, rim, spokes and nipples. Rear wheels are normally sold as either a cassette wheel or freecoaster wheel and commonly use a 9T driver unless otherwise specified.

Before buying a rear wheel, check whether you need Right Hand Drive (RHD) or Left Hand Drive (LHD), the axle type and whether you want cassette or freecoaster.

SHOP ALL COMPLETE BMX WHEELS →   |   FRONT BMX WHEELS →
REAR CASSETTE WHEELS →   |   REAR FREECOASTER WHEELS →

BMX Hubs

The hub has a huge influence on how a BMX wheel feels. Rear hubs vary in axle design, driver size, drive side, points of engagement and whether they're cassette, freecoaster or another hub system.

Front hubs are simpler, but you still need to consider axle type, hub guards, spoke count and spoke compatibility when building a wheel.

SHOP ALL BMX HUBS →   |   FRONT HUBS →
CASSETTE HUBS →   |   FREECOASTER HUBS →

Cassette Hubs

A cassette hub engages as you pedal forwards and forces the cranks to rotate backwards when you roll backwards. The number of points of engagement affects how quickly the hub picks up when you start pedalling.

More points of engagement means less movement at the cranks before the hub engages. Fast engagement can feel particularly responsive for acceleration, technical riding and BMX racing.

SHOP BMX CASSETTE HUBS →   |   SHOP CASSETTE WHEELS →

Freecoaster Hubs

A traditional freecoaster hub allows the BMX to roll backwards without forcing the cranks to rotate. This is why freecoasters are popular with riders doing fakies and backwards tricks.

Traditional freecoasters usually have an amount of freecoaster slack. This is the movement at the cranks before the hub engages when you start pedalling forwards again. Some hubs allow the amount of slack to be adjusted.

SHOP BMX FREECOASTER HUBS →   |   SHOP FREECOASTER WHEELS →

Planetary Freecoaster Hubs

A planetary freecoaster, such as the system used in the BSD Revolution, works differently to a traditional freecoaster. It allows you to roll backwards without the cranks rotating but engages much more like a cassette when you pedal forwards.

This gives riders the backwards capability of a freecoaster with a more direct, cassette-like feel and without the large amount of slack associated with many traditional freecoasters.

SHOP FREECOASTER HUBS →   |   SHOP FREECOASTER WHEELS →

Driver Sizes & BMX Gearing

The driver is the small rear cog on the hub. 9T is the most common size on modern freestyle BMX rear hubs, although other sizes are available.

Common BMX gearing combinations include 23T/8T, 25T/9T, 28T/10T and 30T/11T. These all produce a broadly similar gear ratio.

A smaller front sprocket or larger rear driver makes the gearing easier, while a larger front sprocket or smaller rear driver makes the gearing harder.

READ BMX DRIVETRAIN EXPLAINED →

Male & Female Hub Axles

BMX hubs can use male or female axles. A male axle extends through the frame dropout and is secured with axle nuts. A female axle sits inside the hub and uses separate axle bolts threaded into it.

You'll commonly see specifications such as 10mm female axle, 14mm female axle or 14mm male axle. Always check the axle against the dropout size on your frame or forks.

One advantage of a female axle system is that if an axle bolt becomes damaged it can often be replaced separately rather than replacing the complete axle.

READ BMX FRAMES & GEOMETRY EXPLAINED →

BMX Hub Guards

Hub guards protect the hub, spokes and driver during grinds. You'll normally see them described as drive side hub guards or non-drive side hub guards.

Some hub guards are designed specifically for a particular hub and replace existing hub hardware. Others slide over the axle and sit between the hub and dropout. There are also spoke-mounted designs that protect the hub without attaching directly to the axle.

Some hub guards are universal or compatible with several hubs, while others are hub-specific. Always check the hub guard product description for compatibility before ordering. If you're unsure whether a hub guard will fit, ask Waller BMX and we'll help you check.

SHOP BMX HUB GUARDS →

BMX Rims

BMX rims vary in construction, width, weight, material and strength. With traditional aluminium rims, one of the main differences is whether the rim uses a single wall or double wall construction.

Single wall rims are generally found on cheaper complete bikes and are more prone to damage under hard riding. Quality aftermarket freestyle BMX rims normally use stronger double wall construction, with some manufacturers adding additional internal shaping or reinforcement.

The Effective Rim Diameter (ERD) is particularly important when building a wheel because it's one of the measurements used to calculate the correct spoke length.

If you're running brakes, rim finish also matters. Chrome rims generally provide a very grippy braking surface, while painted or anodised surfaces can feel different with rim brakes.

SHOP BMX RIMS →   |   READ BMX BRAKES EXPLAINED →

Carbon Rims

Carbon rims are another option for high-end lightweight wheel builds and we're building more carbon wheelsets at Waller BMX, particularly for BMX race and premium custom builds.

Carbon rims require careful attention to the correct spoke length, spoke tension and the rim manufacturer's specifications. Because of the additional care and time involved, we charge more for carbon wheel builds than a standard wheel build.

If you're planning a carbon wheel build and aren't sure which hub, spokes or nipples to use, speak to us before ordering and we can help you put the complete setup together.

36H or 48H?

36H is the most common spoke count for modern BMX hubs and rims. A 36 hole wheel offers an excellent balance of strength and weight and gives you the widest choice of modern BMX hubs and rims.

48H uses 48 spokes rather than 36. Although less common than it once was, 48 hole is still a perfectly valid BMX setup and can be a great choice for heavy street riding where extra wheel strength is more important than saving weight.

Compatibility is important: the hub and rim need the same number of spoke holes. A 36H hub needs a 36H rim, while a 48H hub needs a 48H rim.

Whichever setup you're building, spoke length still depends on the exact hub and rim combination rather than simply whether it's 36H or 48H.

SHOP BMX HUBS →   |   SHOP BMX RIMS →   |   USE THE SPOKE CALCULATOR →

BMX Spokes

Spokes are available in different lengths and materials because the correct choice depends on the hub, rim and type of wheel you're building.

14G plain gauge spokes maintain the same diameter along their length. 14G double-butted spokes are thinner through the centre section while retaining more material towards the ends, reducing weight and allowing the spoke to flex slightly differently under load.

Titanium spokes are a lightweight premium option that we're increasingly using on high-end custom wheel builds. They cost considerably more than conventional stainless steel spokes, so they're normally chosen where reducing weight or creating a premium custom build is the priority.

Don't guess spoke length. Even two hubs that look very similar can require different spokes because of differences in flange diameter and flange position.

SHOP BMX SPOKES →   |   CALCULATE YOUR SPOKE LENGTH →

Spoke Nipples

Spoke nipples are available in different materials and lengths, with 14mm and 16mm being common options.

A longer nipple gives more thread engagement range and can be useful with certain spoke and rim combinations, but it doesn't turn a significantly incorrect spoke length into the correct one.

When we're building wheels with titanium spokes, we recommend brass nipples to help reduce the risk of corrosion between the spoke and nipple and to give a strong, reliable wheel build.

The spoke needs sufficient thread engagement inside the nipple without protruding excessively through the nipple towards the rim tape or tube.

SHOP BMX SPOKES & NIPPLES →

Waller BMX Spoke Calculator

Building a BMX wheel? Start here.

The Waller BMX Spoke Calculator is one of the most popular tools we've built. It's used by BMX riders and bike shops well beyond the UK and contains a huge database of BMX hubs and rims, allowing you to select your exact combination and quickly find the spoke length required.

No messing around trying to find flange measurements or hunting through manufacturer technical drawings – if your hub and rim are already in our database, select them and let the calculator do the work.

If your hub or rim isn't listed, get in touch and we'll do our best to add it.

When the calculator gives you a decimal spoke length, round up to the next whole millimetre – for example 183.2mm becomes 184mm.

USE THE WALLER BMX SPOKE CALCULATOR →

Waller BMX Custom Wheel Building

We've been building wheels for over 20 years, long before Waller BMX itself opened. Over the years we've built wheels for everyone from first-time riders through to professional riders, and our wheel builds have earned us great feedback from customers.

We're not limited to standard 20 inch BMX wheels either. We build custom wheels in virtually any size, including 16", 18", 20", 24", 26", 27.5" and 29" wheel builds. That covers everything from BMX and BMX race through to dirt jump and MTB wheels, as well as unusual hub and rim combinations.

We're not limited to standard off-the-shelf spoke lengths either. Where required, we can custom cut spokes to the length needed for the wheel build, which is particularly useful for unusual wheel sizes, hubs, rims and custom combinations.

We build everything from conventional aluminium rim and stainless steel spoke wheels through to carbon rims and titanium spoke wheelsets. Carbon builds require additional care and time and are charged at a higher wheelbuilding rate than our standard builds.

Wheel building isn't just about getting a wheel straight. Correct spoke length, lacing, tension, dish and even spoke tension all matter. A wheel can appear perfectly true but still be poorly tensioned, which can lead to spokes loosening and the wheel quickly going out of true.

If you're building your own BMX wheel, start with your hub and rim and use the Waller BMX Spoke Calculator to find the correct spoke length. If you'd rather have us build it – or you have an unusual wheel size or hub and rim combination – get in touch and we'll help you put the complete wheel together.

USE THE SPOKE CALCULATOR →   |   SHOP HUBS →   |   SHOP RIMS →   |   SHOP SPOKES →