Hmmm, I guessed, I searched, I was wrong several times.Are we in the '70 or '60s? Smaller than 250cc ?
The shock? When I posted that photo I thought that was a big clue but only to you really specialised territory.The third pic was the biggest clue for me.
Feel free if you want to......or you can choose not to and let others less certain to throw out guesses and see how many people get there.Do I say it out loud?