Spokes are the thin rods that connect the outer edge (rim) of the bicycle wheel to its centre (hub). The number of spokes a wheel has depends on the type of bike, but typically spokes have two distinct ends: the hub end and the rim end.
The 'hub end' has a 90 degree bend in it so it can attach to the hub, as well as a disc or 'head' on it so it stays in place.
The 'rim end' has threaded grooves on it so that when it passes through a hole in the rim, a special nut (called a nipple - teehee) secures it in place.
Where inner tubes are used in the bike tyre, special tape is placed inside to cover the ends of the nipples and protects you from punctures!
As well as securing the spoke to the rim, the nipple also creates a certain tension on the spoke which if you've ever seen one break you will know can have a big impact on the sturdiness of the wheel. Too little tension in the spokes means the rim can be easily bent out of shape whereas too much tension can lead to overstressing and a short lifespan.
Spoke Quick Facts
Spokes can be different thicknesses from 'rim end' to 'hub end'
Although they are usually circular, some spokes are flat or oval shaped while some are hollow tubes
Most spokes are made of stainless steel but they are also available in titanium, aluminum or carbon fiber
Nipples can be made of brass or alloy
The process of threading spokes through holes in the hub and rim so that they form a spoke pattern is called 'lacing'