Gary H and I just completed installing a lockable Tundra Lite tailwheel on his Carboncub. The Tundra Lite (http://www.tundratailwheel.com/) is a beautifully machined unit, unlike all other ones, read more about it on his website. The use of the locking mechanism is optional. Its a fully castering non steering tailwheel, however, it is not free castering because it uses adjustable tension to eliminate shimmy along with its flat profile tire and trailing fork design. I've been flying this tailwheel in my previous Highlanders and current Carboncub and I can tell you it works better then any other design out there if you want to eliminate shimmy. Yes, you will need to use some braking during slow taxi, however, I'll take that anytime over shimmy. I haven't used the lockable option yet, however, I've heard from numerous instructors who have used the locking option to trained new tailwheel pilots in Highlanders and had nothing but good things to say about it. I would think it would remove some of the stress and things to think about while learning the Tailwheel Dance. I've also talked to pilots who use the lock during crosswind takeoffs and lands and really like it. Here are some pictures of the install: