Very Cool...
Nothing like having a mountain top of your own to build a track on.
So my brains doing the math and I'm thinking you're gonna have to be fifth gear for enough momentum to sail 145ft.
All of the sudden I feel like a C-class squid again...
If there is a safe part about it... the landing is a table top that has about 35 to 40 feet of flat. landing anywhere on the flat is acceptable. Getting to the down side is the goal but getting to the flat and you will be fine, then you can thump it out from there.
Odd enough, I feel a little too high in the rpm in 4th and a little too low in the rpm in 5th. I do find myself jumping some days in 4th and other days in 5th. In 5th gear it is easy to over jump it if I get a little to high in the rpm.
At 330 on the good days, early in the morning when the dirt was rite and without acceleration bumps you could wring it's neck in 5th gear and still have plenty of landing room. As the day wore on, the the run up got nasty, 4th gear would still do it.
This jump is no fun to over jump by vary much, more than a few feet and I'm shaking the cob webs out of my head and blowing the turn after it!