Being an X-messenger from NYC I can certainly answer some of your questions about locks, but I will first respond to your follow up question to Ian about lockable quick-release skewers. Yes, a set would replace the quick-release skewers on the front wheel, and I think you might also be able to get lockable quick-release skewers for the rear wheel as well.
There is something you should know about lockable quick-release skewers though. My good friend and next door neighbor back in New York, who was also a messenger at the same time I was, tried using them. He liked them for a while, but eventually he ran into some problems. The “key” wrench, which is I believe almost unique for each lockable skewer set can wear down, which could prevent you from easily removing your wheel. I am quite positive the company, who makes them, makes it as convenient as possible to replace a worn key-wrench, but it still means you may have delays if the wrench ever does wear down to the point where it can not tighten or loosen the skewer. Also, you would never want to try a rear lockable skewer on a fixed-wheel bike!
Keep in mind my friend was a working messenger, so he most likely used his bike, and thus the lockable skewers, more than any average cyclist. Also I imagine Ian, who says he has been using the lockable skewers in Berkley, CA and has appreciated them, may not be encountering as extreme cold weather as my friend and you would be experiencing in NY. I would think harsher variants in temperature might contribute to the wear/brittleness of the key-wrench and skewer heads, etc.
I terms of locking up your bike and the FreeRadical in general, you might want to check out a thread called “Locking it up in NYC...“ on the Xtracycle forums, which I posted a few detailed comments on:
One warning, as you might notice someone mention in that thread the “Street Cuff” handcuff style bicycle locks made by Master Lock are NOT advised!
There is also another thread I posted a response to with useful lock information on the Xtracycle forums, which is called “park and lock it”:
It has some of the details in the first thread I just mentioned, but might explain things a bit differently. Once again disregard my comments about the Street Cuff. I still have a street cuff, but I no longer use it for bicycle locking.
By the way, you might be interested in knowing apart from constantly locking up my bike while working as a courier in NYC I also have a pair of Aerospoke carbon fiber 5-spoke wheels on my bike, which cost around $700 for a set. Obviously with that kind of equipment on my ride I do NOT take any chances when it comes to security.
As a side note never use a standard U-lock as a security measure on a bike, unless perhaps it is only securing a wheel to the frame. U-locks can be super-easily broken apart within seconds by wrenching a 2x4 or similar object inside the “U”. I witnessed this first hand done by a bike thief in Manhattan, but unfortunately for that bicycle’s owner I did not recognize the bike as anyone’s I knew. I was not about to risk my own butt and bike over an anonymous bike by confronting a 6’ tall big man, who I had just watched rip a 6’ long 2x4 with nails from a construction sign.
Regarding the possibility of securing possessions on the back of an Xtracycle, well I suppose there are a number of things you can do. I do not believe Xtracycle of any other company has produced anything specifically to address this concern. However, it may very well be possible to purchase a third party locking weather-proof metal tool box or something similar and mount it somehow onto one side of the FreeRadical. I would imagine this might require bolting or hose-clamping through the metal box itself to secure it properly to the FreeRadical. Obviously using some kind of metal container would pump up your bike’s weight quite a bit. It might be possible to purchase a much lighter, though not as theft resistant, lockable plastic bin. Specifically I was thinking of some kind of portable and lockable beach//outdoor cooler. Naturally you would still have to figure out some method to secure the cooler to the Xtracycle.
Personally, I have never used anything of the sort on my bike. I generally load up one side with an oversized messenger bag and take that with me if I am going to be away from my bike for more than a minute or two. However, I have also used another tactic to leave possessions on my bike for extended periods of time, which involves a “disguise.” I actually started using two contractor-grade black garbage bags to slip my messenger bag into, so they would keep my messenger bag dry and more respectable/professional looking when I would go into the offices of my clients. Doing this also kept my messenger bag from dripping all over the place when I brought it in my own home. Eventually after doing this for a while I realized having my messenger bag inside two garbage bags disguised it enough to cause any would-be thief of opportunity enough disinterest to leave my stuff alone. Who would really want to start opening a big garbage bag on the back of a long weird looking bike anyway?