.. practice your Bunny Hop .. if you can do it well, you can beat all your competitors around the course in cyclocross races .
as opposed to getting off, jumping over the barrier , and geting back on ..
you can also raise the whole bike and yourself up to the height of the sidewalk
and then you land, with a light impact, on the sidewalk height.
You jump up and bring your bike up underneath you , as once your body mass is in motion ,
it is larger than the weight of the bicycle..
unless your bike weighs like a T36 Tank.
http://www.wikihow.com/Bunny-Hop-on-a-Bike
also used in Observed Trials, bounce hops with the brakes locked .. works on Unicycles too.