A Perth man who was knocked off his motorcycle by a rope that was strung across a main road in Perth's CBD said he wants the teenagers allegedly responsible to clean-up their act.

Lawson Mills, 19, was travelling to his Guildford home from his job as a waiter in a Perth restaurant about 11.30pm on Thursday when the incident happened.

Mr Mills told ABC 720 he was furious the group, which he believes included children as young as 13 or 14, thought the stunt was appropriate.

He said he had slowed down after noticing the group loitering ahead, but did not see the rope until it was too late.

"One of the ends of the rope hadn't quite been tied down properly so I managed to ride through it," he said.

"But the rope wrapped around my neck and slowed me down, pulling me off to the side of the road."

Hit from behind with glass bottle

Mr Mills said he then went to confront the group, but they were unresponsive.

He said he then went across the road to the Perth train station to talk to the transit guards.

"I asked if they were going to do anything, but they said they couldn't leave their post," Mr Mills said.

Mr Mills said he then went back to the group, but he was hit from behind by a glass bottle.

"The rest of it is a bit of a blur. I fell to the ground and curled up," he said.

"I think there were a couple of guys that had been watching that picked me up and took me back to the train station."

Mr Mills said two other transit guards then arrived at the scene, calling emergency services and making sure he was alright.

But he said the response from the first two guards was disappointing.

"It was somewhere between apathetic and indifferent," he said.

"I'm not a particularly imposing guy so a bit of physical presence would have gone down well.

"Who knows if the situation might have turned out differently."

Mr Mills was treated overnight for whiplash, abrasions, rope burn and for a gash to the back of his head, which required around five staples.

He said while he knows the situation could have been much worse, he is furious at those he believes are responsible.

"If I had anything to say to them I'd say to 'pull your head in. What are you doing?'," he said.

"Your actions have consequences and if you have a bit of decency go and speak to someone about this. Sort yourself out."