What is Urban Assault/Trials riding? I have a general idea what it is.
Trials riding is negotiating a set course of "impossable to ride" obsticles without puting your feet down (dab). Fewest dabs wins. Trials bikes generaly have smaller frames, tighter geometry, and super-beefy 24 or 26 inch rims and hydro brakes. The saddle is a tiny afterthought (your never sitting). This
http://pe.biketrials.com/Brisab26/brisab26.html is a trials bike.
Trials is probably one of the most amazing things I've seen done on a bike. GT's Hans Rey is the undisputed God of trials. Theres a collection of photos, mpegs, etc on his site
www.hansrey.com
Check out
http://www.natrials.com/2001/24snowshoe.html for some great observed trials pics.
Urban assult is you an unoffical trials ride at your local parking complex/loading dock/university commons area. Put some fatter tires on your mtb, drop your seatpost all the way, and go have some fun. Just be sure to have "911" on speed dial on the cell-phone.
This:
http://roger.ecn.purdue.edu/~aeromik...urdueride.html Is a serious session!
Trials rocks. I just wish I had that kind of balance.