I know this isnt clothing but what if they had some form of small, portable winch system that takes a minute or two to set up (so that it's not to easy to escape while being chased). The winch could have a thin yet extremely long, flexible and durable rope that can be attached to belts or harnesses. It could be remote controlled allowing the user to lower or elevate themselves at diffrent speeds at will. One of the short comings could be that while the rope is long enough to reach down most buildings, it's not long enough for ALL of them, so the characters might sometimes be forced to take the stairs. Once all the characters are at street level a button or somthing can be used to release the winch at the top of the building, letting it fall back down to be used again.