Yeah I wouldn't let anyone touch my bike (if was for sale) without cash in hand. I bought my bike without riding it. The original owner tested it in front of me, and a good visual inspection of all the important areas.
I guess it's kind of a judgement thing. First ask what sort of bikes he has ridden before. If he comes with full gear and his own helmet and shows you that he has a full M license and looks to be a serious buyer I would take him to the nearest parking lot. Than I would allow him to ride the bike around the parking lot with the car motor still running.
For me every bike I've bought all the owners offered me to ride it without asking for it but it's probably because I show up on my own bike as someone said earlier.
you can't "force" someone to pay. You can try and take them to small claims court if you have their info.
I know it's risky. But when they here what I do for a living, they let me ride it.
As long as your bike's insured, I don't see what the big deal is. No tire-kickers though - just serious buyers. I wouldn't buy anything "as is" without taking a test drive. No one's going to hand you full asking price to take a test ride.
I had one guy show up in a pickup. He took my bike for a test ride, handed me cash, then loaded it up in the back of the truck. I let him take my new bike for a spin too.
NEVER LET SOMEONE TEST RIDE YOUR BIKE. If you are selling your bike you never let someone test ride it. You can see it very easily if a bike has been abused, and the only thing that someone can tell on a bike is the gearing. If the shift forks are bent, then riding it is an easy way of telling, BUT the fact that if they drop your bike..... Well that outways everything. No sensible dealer would let someone test ride a bike, neither should a private sale.
There are too many test riders out there.
Ride Safe.