How do I know if my aluminum bike frame is cracked?
If you're concerned that your aluminum bike frame may be cracked, there are a few things you can do to test the theory. First, use a hairdryer or heat gun to warm up the frame enough to make it expand. If the frame cracks when it expands, it's likely that the frame is indeed cracked. If the frame doesn't crack when it's heated, it may still be cracked, but it's less likely to be. If you don't have a heat gun or hairdryer, you can also use a cold iron to see if the frame cracks. If it does, it's likely that the frame is cracked.