We have the Pinhead system on our RW4 and my partners mountain bike. However we use chains and locks for security while parking our bikes. The Pinhead system helps to keep our wheels, seat and handlebars on our bikes while parked. I haven't been able to purchase the Ulock Pinhead uses. The Lockpicking lawyer says it is very difficult to pick but, of course, it would fall prey to an angle grinder in a few seconds.