There are a few things to consider when purchasing a kickstand for your bike. First, you need to know the diameter of your bike's tubing. Most adult bikes have either 1-1/8" or 1-1/4" tubing. You will also need to know the length of your chainstay. The chainstay is the horizontal tube that runs from the bottom bracket (where the pedals attach) to the rear axle.
Kickstands are typically measured in two ways: overall length and leg length. The overall length is the distance from the tip of the stand to where it mounts on the frame. The leg length is simply the distance from the tip of the stand to the ground when it is extended. It is important to choose a stand with an adequate leg length for your bicycle; otherwise, it will be difficult or impossible to prop up your bike without tipping it over.
Generally speaking, you will want a kickstand that extends between 10-12 inches fromthe point where it mounts on your frame. As for leg length, a good rule of thumb isto choose a stand with a leg that is roughly half as long as your bicycle's wheelbase (the distance between front and rear axles). Use these guidelines to select a suitable kickstand for your bike, and be sure to double check that all measurements are compatible before making your purchase!