Travel refers to the amount mountain bike forks compress and extend. Forks are designed to compress, or sag, under the down force of your upper body weight as you encounter bumps. The forks extend when you lift the front end or launch off a jump. Measuring the travel allows you to set up the suspension for certain types of terrain. Once the measurement is taken, you can adjust the shock dampers for less travel and a stiffer ride or more travel and shock absorption. Ask an assistant to help when you measure the travel on mountain bike forks.
Ask an assistant to balance the bike upright. Identify the circular rubber wiper where a shock rod enters the top of one of the fork tubes.
Attach a small nylon tie around the shock rod and push it down against the top of the wiper.
Ask the assistant to take a position on one side of the bike and grip the top of the handlebars near the steering headset. Take a position on the opposite side of the bike and grip the top of the bars near the headset.
Press down on the handlebars with your combined body weight and compress the forks until they bottom out. You will notice the wiper pushes the nylon tie up the shock rod as you compress the forks.
Allow the bike to return to its normal position. Allow the nylon tie to remain at the new position on the rod.
Ask the assistant to lift the front wheel off the ground so the forks extend fully. Measure the distance from the nylon tie to the top of the rubber wiper to determine the travel of the forks.