I don't use a cane for walking, just getting up, so my cane hand (right hand) is free if I am standing up.
He was straddling a bicycle because he tried to ride away until I bumped the bike into the black metal trolley safety railing
https://www.google.com/maps/@32.708...4!1s3iKhJ8ISijVXZ7iKp-pppQ!2e0!7i16384!8i8192
He ended up with one leg over the bike frame and the other on the ground holding up his weight, with his body leaning against the railing. I wasn't going to let the bicycle forward, and he wasn't in a good position to go backward so he was trying to get me out of the way.
His left hand was busy holding a pack or bag under his left armpit. He was punching at me with his right. His first blow to my left ear I didn't see coming, and it knocked off my hat. After I bent down to pick up the hat, as I rose up I came up with the cane in a one-handed baseball swing and caught him in the left temple or ear as hard as I could. He swung again and I blocked it with my left arm (scrapes and bruises today). I was poking him in the chest with my cane to keep him away and trying to push things out of his bag or get the cords around his neck. The third swing (the third I was aware of anyway) I ducked and he just caught my glasses and the bill of my cap. When I bent down to pick them up, I brought the cane up the same way as before and hit him in the same place.
By then he was ready to give up the bike, so he vaulted over the front wheel with both his bags, running faster than I could hope to chase.