peddle to the nearest lightning safe shelter and hope that lightning doesnt start.
If lightning does get close, get off the bike. lay it down. walk about 50 feet away and assume the lightning position. preferably in a ditch.
http://www.ekshiksha.org.in/images_n...I/figure_6.JPG <------ lightning position
more info:
Lightning Safety - How Lightning Works
dont lie flat on the ground
dont use things like trees as shelter. As they will attract lightning.
dont stand in an open field
dont set up any tents or anything like that.
do try to find a dip, ravine, ditch, depression, sinkhole
do use the lightning position
do get into a car if you can
do get into a building if you can