Replying to I just wanted to sell my bike ...

So about one year ago a friend of mine came to me with some guy who wanted to test my old Downhillbike (old but I have drove it twice, so it is as good as new). So I gave it to him, that he can test it for a few days, and afterwards he will tell me, if he would buy it. He looked reliable and was a friend of my friend, so it was no real problem for me. Here now comes the problem. This dude has this bike now for one year. And every call I gave him, he was allways like ya shame on me, I will bring it to you on monday or whatever. 
NOW I am really pissed of, and I will send him a bill about like 1000 Euro, because if he has this bike still for one year, I would say its allready his own. And I dont think, that it got better in this time. And if he wont pay for it, the bill will defenately push him to bring the fucking bike back.