Aluminium is an incredible material for building bikes. It has great strength-to-weight, can be shaped easily and is recyclable. But it also has a limited safe life. The gradual weakening of aluminium that bike frames, forks and fasteners experience over time is a process called 'metal fatigue'. While the safe, usable life of a bike will depend predominantly on how often and the manner in which it is ridden, a good rule of thumb is that if your aluminium bike is over ten years old, you should think about whether it is time to replace it. If you have a question about the condition of your bike, we recommend that you take it to your local Trek retailer for inspection. They can give you a better idea of the condition of your bike and its parts and provide recommendations for what to do next.