not that i know a darned thing, but i prefer to ride (at least a couple miles) on any work i do before a race. how many times have you had to stop on a ride and make another subtle adjustment after working on your bike?
don't let it wait until the last minute, unless you're a factory mechanic and make no mistakes. if all is well, the night before a race i pack my bike in the truck, and double check all my gear, and relax.
(off-road adventure for the sentient being)
That reminds me of the time at Top Gun when we were in staging and Gomer asked me to hold his bike and he ran to the tree line about 20 feet away to take a whiz. It seems that no matter how much he drinks he rarely has to go to the bathroom unless the start of a race is near :)