Lightning travels thousands of feet through air...a damned poor conductor. Why would it have problems with traveling through an inch or so of rubber...another poor conductor?

Lightning can't hurt you if you are in a car or a house or in a metal cage but those are Faraday cages which direct the discharge away from the inside of the cage to the ground. On a bike you have only one side of the Faraday cages. You probably need all sides to protect you. You could surround yourself with a cube of bicycles - one on each side - and that might give you protection or you could surround yourself with some kind of 'enclosure' like a body of sheet metal. But you'd need more power to carry it so an internal combustion engine would be the best way to do that. Wait a minute...that's a car

Honestly, the best way to deal with lightning is to take shelter. Trees aren't good, building are. A bridge will do. I know I made fun of mjw16 for it...sorry However do be very careful if you are under a bridge in a rain storm. We had a child swept away and killed here in Colorado a year or so ago because he got caught in a flash flood.