The skewer is the shaft the runs through the middle of the hollow axle which attaches to the forks of the frame. This is the tool that attaches itself to the hubs, connecting the wheel to the frame. Skewers are an extremely important component of a bike and need to be carefully considered if buying separately. Some skewers are only designed for specific types of bikes so make sure when purchasing skewers you know for sure that they will fit the type of bike you have. For further advice on this tell the retailer what type of bike you will be applying the skewers too and if you have chosen correctly. If this precautionary method is not applied then you could spend up to $150 of your own money on a product that doesn’t suit your bike.