ALL UNREAD TOPICS
Agree ... With "suitable" modifications on the Hayabusa (don't know about anything else), 250 - 270 mph is marginally safe. The aero fairings that allow current "stock" framed bikes to eclipse 270 have major issues with cross winds at any speed.
So many aspects to it…How pronounced is the “side lift” from a crosswind component?What are the effects of increased cross sectional area - both fairing and tail sections?Sustained acceleration rate and reduced contact patch on the front wheel - and the resulting change in steering? How dynamic is the change in handling if you ease up on the throttle and increase weight on the front in reaction to some handling issue? What if you chop the throttle quickly if something bad is happening “right now”?!If you do start generating a lot of “side lift” and something causes that crosswind component to exceed the “critical angle of lift” and it “stalls” - what happens to the handling of the bike?! What happens if this flow manages to stay attached (or re-attaches) to the tail section while the “side lift” is lost on the fairing with the “side stall”? How does all this change if you try adding a “flat bottom” to the fairing?I bet that is just the tip of the iceberg …
Quote from: fj1289 on November 29, 2021, 08:28:30 PMSo many aspects to it…How pronounced is the “side lift” from a crosswind component?What are the effects of increased cross sectional area - both fairing and tail sections?Sustained acceleration rate and reduced contact patch on the front wheel - and the resulting change in steering? How dynamic is the change in handling if you ease up on the throttle and increase weight on the front in reaction to some handling issue? What if you chop the throttle quickly if something bad is happening “right now”?!If you do start generating a lot of “side lift” and something causes that crosswind component to exceed the “critical angle of lift” and it “stalls” - what happens to the handling of the bike?! What happens if this flow manages to stay attached (or re-attaches) to the tail section while the “side lift” is lost on the fairing with the “side stall”? How does all this change if you try adding a “flat bottom” to the fairing?I bet that is just the tip of the iceberg …Tip of the iceberg indeed! All great questions!A couple of years ago I ran some simulations to calculate side lift using a simulator I found on a NASA site. Somewhere I have the notes but IIRC it wasn't very hard to generate a couple hundreds pounds side force using typical fairing size and a small cross-wind component. I'll look for those numbers and/or try to regenerate them. We typically think of wings as being asymmetrical but symmetrical wings will generate lift if the angle-of-attack isn't zero degrees.
Hayabusa, ZX14, etc, chassis with rider, see center of gravity average at, and just below steering head heights, this combined with 23* 24* rakes, serve to exacerbate high speed handleing