Road Bike Wheels | Carbon Wheels Cycling

Posted by Sam on March 26th, 2021

A carbon bicycle wheel such as the ICAN carbon wheels are most commonly a wire wheel, designed for bicycle. A pair is often called a wheelset, especially in the context of ready built “off the shelf” performance-oriented wheels.

The first bicycle wheels followed the traditions of carriage building: a wooden hub, a fixed steel axle (the bearings were located in the fork ends), wooden spokes and a shrink fitted iron tire. A typical modern wheel has a metal hub, wire tension spokes and a metal or carbon fiber rim which holds a pneumatic rubber tire.

Hub

A Shimano Dura-Ace freehub style hub
A hub is the center part of a bicycle wheel. It consists of an axle, bearings and a hub shell. The hub shell typically has 2 machined metal flanges to which spokes can be attached. Hub shells can be one-piece with press-in cartridge or free bearings or, in the case of older designs, the flanges may be affixed to a separate hub shell.

Axle

The axle is attached to dropouts on the fork or the frame. The axle can attach using a quick release – a lever and skewer that pass through a hollow axle designed to allow for installation and removal of the wheel without any tools (found on most modern road and mountain bikes).

nut – the axle is threaded and protrudes past the edges of the fork/frame. (often found on track, fixed gear, single speed, BMX and inexpensive bikes)

bolt – the axle has a hole with threads cut into it and a bolt can be screwed into those threads. (found on some single speed hubs, Cannondale Lefty hubs)

thru axle – a long axle, typically 20 mm (110 mm width), 9 mm (100.33 mm width) in diameter for durability, onto which the fork/frame clamps. (found on MOST free ride and downhill mountain bikes)

female axle – hollow center axle, typically 14, 17, or 20 mm in diameter made of chromoly and aluminum, which two bolts thread into on either side. This design can be much stronger than traditional axles. (found on higher end BMX hubs and some mountain bike hubs)

Modern bicycles have adopted standard axle spacing: the hubs of front wheels are generally 100 mm wide fork spacing, road wheels generally have a 130 mm wide rear wheel hub. Off-road and “mountain” bikes have adopted a 135 mm rear hub width, which allows clearance to mount a brake disc on the hub or to decrease the wheel dish for a more durable wheel.

Bearings

The bearings allow the hub shell (and the rest of the wheel parts) to rotate freely about the axle. Most bicycle hubs use steel or ceramic ball bearings. Older designs used “cup and cone”, whereas some modern wheels utilize pre-assembled “cartridge” bearings.

Freehub vs freewheel hub
A “cup and cone” hub contains loose balls that contact an adjustable ‘cone’ that is screwed onto the axle and a ‘race’ that is pressed permanently into the hub shell. Both surfaces are smooth to allow the bearings to roll with little friction. This type of hub can be easily disassembled for lubrication, but it must be adjusted correctly; incorrect adjustment can lead to premature wear or failure.
In a “cartridge bearing” hub, the bearings are contained in a cartridge that is shaped like a hollow cylinder where the inner surface rotates with respect to the outer surface by the use of ball bearings. The manufacturing tolerances, as well as seal quality, can be significantly superior to loose ball bearings. The cartridge is pressed into the hub shell and the axle rests against the inner race of the cartridge. The cartridge bearing itself is generally not serviceable or adjustable; instead the entire cartridge bearing is replaced in case of wear or failure.