How do you fix a bike when it does not petal?

If a bicycle doesn't pedal, there could be a few different reasons for the issue. Here are some steps to troubleshoot the problem and fix it:

1. Check the chain. Make sure the chain is properly connected to the front and rear sprockets. If the chain is disconnected, reattach it by pushing the pin back through the link.

2. Check the derailleur. The derailleur is the mechanism that moves the chain between the different sprockets. Make sure the derailleur is properly aligned and not bent or damaged. If it's misaligned, you may need to adjust the derailleur cable or the derailleur itself.

3. Check the cables. The cables are responsible for controlling the shifting and braking of the bicycle. Make sure the cables are properly connected to the brake levers and shifters. If the cables are disconnected, reattach them.

4. Check the brakes. Make sure the brakes are not engaged. If the brakes are engaged, disengage them by pulling the brake levers.

5. Check the pedals. Make sure the pedals are properly attached to the cranks. If the pedals are disconnected, reattach them by screwing them back onto the cranks.

Once you have checked these things, try pedaling the bicycle again. If it still doesn't pedal, there may be a problem with the internal components of the bicycle, such as the bottom bracket or the hub. In this case, you may need to take the bicycle to a bike shop for further repair.