yes but i sell wheels as a living..... the spigot ring takes the weight of the wheel off the nuts and places it on the hub..... this is very bad if you dont have them..... speak to anyone with a mini and spaced out rims. lots of wheel bearings and wheel nuts later.... bad idea,,
but you can get whats called hub-centric spacers that bolt to the hub like a wheel and have the correct spiggot size to fit on the wheel itself...
but never run a wheel without one... its not safe, (unles your wheel is the correct bore size for your hubs)