how do you get a motorcycle tire back on the bead while its still on the motorcycle?
I think you are going to need a new tire there ace because it should not have come off in the first place.
Try using a tie-down strap wrapped all the way around the center your tire and cinched pretty tight. That works if your rim is still mounted or off the bike. (lawn mower, trailer, truck, unicycle .) Removing the core of the air stem helps a lot.
If you mean get the sidewall of the tire back onto the wheel, you need to get one side of the bead down into the drop center of the wheel, the smallest diameter part. First lube the bead with dishwashing detergent or the silicone spray wax you can use on dashboards. Get one bead down into the drop center and then working away from that spot, carefully pry the bead back on maybe an inch at a time, going both directions. Don't use a screwdriver because they are too narrow, use something wider. If you mean get the beads to seat on the rim, do as guardrailjim said, if that doesn't work use the ratcheting hold down strap around the center of the tire and if that doesn't work, use the starting fluid trick.
They are big hairy spiders
