If you don’t want to order rims and spokes from Holmes Hobbies to build your own wheel, the next best option is to add stainless steel washers to Holmes Moped 6mm nipples. This allows you to fit the affordable Sapim stainless steel 12ga spokes that are recommended into the 8mm holes found on common 1.6-inch wide moped rims.
You will need to dish these washers into a shallow bowl shape, which is easily done with a cheap 3/8-inch hydraulic tubing flare tool. Standard 12ga bicycle nipples will require washers when used on any moped rims. Common 12ga nipples have a 4.6mm body, and a 5mm washer works well. For Holmes moped nipples (6mm 10ga body with a 12ga hole), an SAE #12 washer has a 6.4mm ID.