You want to ensure you get the right Stacked Weight Pin for your selectorized cable machine or functional trainer. The holes can be deceiving at first glance as there isn't much difference between 8mm and 10mm. Here are some ways you can ensure you order the right pin the first time for your machine.
Use a digital caliper. A digital caliper can precisely measure the diameter of the pin hole size for the accurate selection of your Stacked Weight Pin. If you do not own one, they can be found on Amazon for about $10.
Measure your selector pin. Measure the diameter of your selector pin to determine the mm size needed.
Use a #2 Pencil. A standard #2 pencil is fairly common in most homes, and one that can be used as a quick test for sizing and fit. A Standard hexagonal #2 pencil is approximately 7-8mm in diameter. For a quick test, insert the pencil in your weight stack pin hole and use the following as a guide to select your Stacked Weight Pin.
Purchase an 8mm Stacked Weight Pin if...
• The #2 pencil has minimal wiggle room or fits snugly
Purchase a 10mm Stacked Weight Pin/Short Stack Weight Pin...
• The #2 pencil has a gap or a lot of wiggle room in the pin hole compared to the machine pin
➜ Buy the 10mm Stacked Weight Pin Here
➜ Buy the Short Stack Weight Pin Here
Shown above*, a #2 pencil measured in an Inspire FTX Trainer. This machine takes a 10mm Stacked Weight Pin.
*photo courtesy of Brian Pham @phambri.