Bicycle Wheel Buyers Guide

Buyers Guides

Bicycle Wheels

Bicycle Wheel Buyers Guide

Replacing your bicycle wheels is one of the most cost-effective upgrades you can perform.
Your bike will climb, sprint and stop better with a lighter wheelset.

So, if you want to improve the performance of your bike, choose the best wheelset you can afford...

Typically, bicycle wheels consist of 4 main components - the rims, the hubs the spokes and spoke nipples.

Rims

The part of the wheel that your tyre fits onto are the wheel rims.

There will be a number of small holes to accept the spokes and a larger hole for the tyre valve. On more expensive rims the spoke holes may also have brass eyelets to strengthen the hole and spread load.

On road bike wheels, the side of the rim will have machined braking surfaces. The braking surface sometimes has a groove in it (a 'wear indicator').

Most modern MTB wheels will use disc brakes. The brake disc will be bolted to the hub.

Rim Materials & Construction
Typically, bicycle wheel rims are made from aluminium. During manufacture, the aluminium rim is extruded (like toothpaste being squeezed out of a tube) and then chopped into lengths. These lengths are bent into circles and then the ends are pinned together to join them.

Lighter wheels mean that your bike will accelerate faster and hill-climbing will be easier. Some cheaper bikes will use steel for rims and hubs. Steel rims are considerably heavier and wet weather braking can be poor.

Top of the range aerodynamic wheelsets for triathlon and time trialling often use carbon fibre in their construction.

Hubs

The centre part of the wheel is the hub. The bearings that allow the wheel to spin are housed in the hub. The axle also runs through the centre of the hub.

The spokes of the wheel are laced into holes in the hub flanges.

On the rear hub there will be a fitting (the freehub) to accept the sprockets. A singlespeed hub will have a screw thread to accept the single sprocket.

Spokes

The spokes are the most highly stressed part of the wheel.
Spokes are basically lengths of wire with 4 distinct sections...
  • A flattened head hold anchors the spoke into the spoke hole
  • The 'elbow' - the right-angled bend.
  • The body - the unthreaded section.
  • A 10mm long screw thread.

    The cheapest spokes are plain steel. Rust-free stainless steel can also be used to decrease weight.

    To decrease spoke weight further spokes can be 'butted'. This means the spoke is fatter at the ends (where most stress happens) and thinner in the middle.
    Wheels built with butted spokes tend to be more durable as the thinner part of the spoke stretches rather than breaks under stress.

    Aerodynamic bike wheels will use flattened or ovalised bladed spokes to lessen air resistance. Flat spokes cut through the air better than round spokes.

    The more spokes a bike wheel has, the stronger (and heavier) the wheel will be. The fewer spokes a wheel has, the lighter and more aerodynamic the wheel is. Spoke counts range from around 20 (a front wheel suitable for racing) to 48 (a rear wheel suitable for touring with very heavy luggage or a tandem bicycle).

    The larger the number of spokes, the longer the spokes should last before breaking - stress being shared among more spokes.

    Spoke Lacing Patterns

    Spokes are fitted to a bicycle wheel in various patterns. Most common is the 3-cross or 4-cross pattern. This means that each spoke crosses 3 or 4 others between the hub and the rim.

    On a radial-spoked wheel, the spokes do not cross any others - this allows fewer spokes to be used and saves weight. Usually only front wheels use radial spoking and then usually only on high-performance bicycles. A radially spoked rear wheel would not effectively transfer the drive-torque from the sprocket to the wheel rim.

    Some high performance rear wheels use a different spoke lacing pattern on each side e.g. radial lacing on one side and 2 cross the on the other - the cross laced side transfers drive to the rim.


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