Sounds like a cop that maybe had too much time on his hands that day. Or, he had been hassled by a superior for not having enough "contacts" on his activity sheet. I once over heard a CHP officer tell another officer that he got called into the supervisor's office for that one.
Did he run a warrant check on you? A close relative is a Deputy Sheriff and he says that their main job is finding people with outstanding warrants and the main way of finding them is to do traffic stops of everybody that fits within a general profile.
Driving a Volvo station wagon that is in good condition and waxed and polished and not weaving or doing anything obvious will never get stopped. Driving a beat-up car that is dirty and a few other little things that most don't think of, like being really thin (meth users are usually thin), having messed up, dirty appearing hair (I guess druggies tend not to take care of themselves), and you are a likely candidate for a traffic stop just to check for warrants or drugs. And they can come up with anything they want as "probable cause" if they really feel that you are somebody that might have a warrant or drugs.
Don't get me wrong, I'm not being critical of police or their tactics, since I have a lot of them in the family and even more as friends.
But, sometimes cops are stopping drivers for a completely different reason than they say. I'm not suggesting that you fit any of the above, since it is probably hard to make any judgement about a person on a motorcycle that is wearing a helmet but maybe he needed some activity to right down on his sheet or he just wanted to talk to you to keep awake or maybe he just wanted to see your COOL BIKE!