I'm regularly changing mine back and forth from solo to 2-up and don't remember the actual length. Take one to HomeDepot/Lowes and pick up a slightly longer match. BTW, they strip easily if not lined up just right (and juggling the fender, sissy bar and saddlebag brackets is a PITA), so I just keep a jar of them in different lengths. If you look around, you'll find them with a knurled hex keyed head that do make it easier.
