What brand and viscosity oil are you using that does this short duration performance?
I've been using Castrol 4-stroke motorcycle oil (10/40) even though the bike specs calls for 10/30 (I believe). I've also used the OEM Honda oil, with seemingly better results (but still much the same with respect to duration). I've yet to try synthetic, but have more/less decided to buy the OEM Honda synthetic on Tuesday to see if that makes a difference in longevity.
It's very odd, but the bike does see 'severe' service. At 120 KPH it's typically doing 11,500 RPM and I try to keep it there all the time if possible (on the freeway). Basically, in order to pass vehicles you need to continually wring it's little neck. Around town, it's perfect, on the highway, it's a blast, but again, only if you drive the livin' snot out of it at all times. If you don't keep your momentum up (usually by passing everyone) you get bogged down on hills/inclines etc.
The engine/transmission only holds one liter of oil, the bike runs at proper temp all the time (no matter how you drive it - 1/4 up the gage) and the oil always looks new (seemingly zero blow-by). The oil does have a sharp acrid smell to it though when you take it out. It's not a nice smell.
The magnetic drain plug has almost no material on it, the internal oil screen never has anything on it other then a slight bit of 'fuzz'. So, internally and functionally, the engine is pretty much perfect. It's also fuel injected. It's been like this since I got it with 700k on it.
That's why I can never seem to figure out just what the bike does to the oil to make it 'wear out' so quickly. As God is my witness, you change it and the bike's performance will be smoother, faster, and rev higher considerably faster - even when the old oil is relatively 'new' and crystal clear.
I'd give my let nut to understand what is happening to the oil....
BTW, just got back from a long ride on the freeway and the front brake worked unbelievably well - again, I can tell that the 4 month olf fluid was changed out. It's also night & day different so it's not me or my imagination!