Every string we put into a tennis racquet is “pre-stretched”…not just sometimes but every time!  This is an old post but worth seeing again I believe.

Why?

Pre-Stretching slows down the “creep” process that reduces string bed stiffness, (tension loss) and to feel what the string is doing while being stretched, and making some strings easier to handle during the stringing process. Some strings stretch a lot and some strings don’t. We can tell a lot about how the string should be handled (and the application) based on pre-stretching. 

How?

Most stringing machines have a pre-stretch feature, including ours, however, we prefer the entire length method. All forty (40) feet of it!  If you have a room, that is forty feet long, or a perfect outdoor spot use it!

The proper tools and proper technique make pre-stretching an easy and performance-enhancing procedure.

Parallel Plier

The object is to pull the string straight.  The plier needs to grab the string as shown.

The arm and wrist should be in the neutral position as shown so the stress is on the string, not your body.

The other end of the string can be secured through a hole with a “starting clamp” as you will see below.  These clamps are rated to hold 90 pounds so it is not in danger of letting loose!  

Tree Hole

We probably hold the string at tension for 30 to 40 seconds after applying four or five quick short stretches.

For many years we used a high-tech device to measure how much force we apply during the stretching procedure.  The force we apply is between 35 and 40 pounds using this rig…

This scale is rated to 100 pounds.  The string is inserted through a hole in the bracket and secured by a starting clamp, then using two hands grab the handle and begin to stretch the string while reading the force on the scale.  After using this device for a while it will become a matter of “feeling” not measuring the force.

Stretch Scale