I grew up out in flat Kansas. Those days there was a lot of flat tracking around at the different fairgrounds. So when I was a pretty little kid I'd always see bikes being pulled with the rear tire on the road behind cars. Pull the drive chain and the front tire, hook her up and go. But I never knew just how they did it. Something at the bumper to clamp the axle to? They didn't have those tire cradle deals like you see sometimes now. Trivial, but I've often wondered, and don't think I ever saw it again when older. Anybody else see that back then?
When I was a kid, my older brother was going to college in Phoenix. He got a 250cc Wards bike when home for the summer. My grandparents, who lived in Tucson, also visited that summer. Rather than have my brother try to ride that bike all the way to Phoenix, my dad and grandpa had a bracket made to tow it just like you describe. The bracket just clamped to the bumper like a lot of trailer hitches back then. As far as I remember, everything went OK. Gary
I think some were a loop the front wheel sat down in and the wheel was tied into it. I’ve tried google for an image but no luck
I built one in the '60's to tow my Suzuki trail bike behind my Ford Fairlane. I built a clamp-on bracket with an arrangement to accept the front axle and clamp the forks over the hub-like bracket. Removed the chain and drove away. It worked quite well. Al Hook
My friend Ernie Barkman's knucklehead drag motorcycle. Being towed by his 39 standard and homemade trailer with model a axle. Ernie built the trailer and draw bar. I Googled vintage motorcycle towing and these came up