Spoke wrench

A spoke wrench is a small wrench used to loosen or tighten the tension in a spoke. Each spoke has a nipple where it pierces the wheel rim. The end of the nipple is square shaped. The spoke wrench attaches here. Care must be taken when changing spole tension because it is very easy to turn the nipple in the wrong direction and put the wheel hopelessly out of true; that is, the wheel will spin crooked.

See bicycle repair.