"Helmet Hook"

[Lee]

We use the plastic ones. Size 2 is 2 inches long. A 1 inch would be pretty tiny.
I remove the little plastic cover on the rear rack and make a loop with thin double sided Velcro.
When I put the plastic cover back on it traps the Velcro.

Good tip about the size ... I guess #2 mean 2" overall length? I think I will get a 2-pack of #2. Have to investigate the attachment first since neither bike has the RS rack.

Yes, two inch overall length.
These S hooks are handy, I probably have a dozen of them.
Besides Amazon and Ebay you can find them at camping or hardware stores.

Depending on your racks you could use a large size and only hook it on the rack or other spot when you use it.
We leave our S hooks in place all the time but could remove it in a second if I wanted.

Our main reason to use the hook is to keep the helmet from falling off the bike, not lock it.
When we need to lock the helmets we use a cable.