2006 Hayabusa pics!!

In crosswinds or beside 53' semi's, the Busa I have, as well as other's I have driven will not track as straight as my R1 or my 10R and they are the ones in fact that require more user input to track straight, not the 1000's

This is understandable. The Busa was designed to ride in headwinds...not crosswinds. Look at the side profile - HUGE!!

Even the multi-million dollar F1 cars are CRAP when you have cross-winds. Read the race weekend reports from the "British GP at Silverstone" and look for the part where they talk about the section of track just before and into the entry of the "Bridge" curve.

Image:
silverstone03_map.gif


Crosswinds are a HUGE problem here and the cars are twitchy on entry.


I cannot believe "educated" people have been arguing about "Aerodynamics" without understand the following points:

* What was the design focus for the Hayabusa aerodynamicist?
* What happens when you have cross winds and a large profile with no through-holes (Busa) ?
* What happens when you have crosswinds and a small profile with more through-holes (liter bikes)

Now I dont know about performance figures etc. but here is a little education about bike stability under different conditions:

Weight and CG:

CG : Center of Gravity.

If the weight is placed higher on the bike then you have a "top-heavy" bike. Fine in a straight line but once you start to "lean" the bike then you will be at a disadvantage. Think of it like this:

Take a 20 lb dumbell and tie a stick to it's handle so that the dumbell is like the handle of a sword and the stick is the blade of the swird. Now hold the "sword" by the handle and swish it around...feel ok? Good.

Take the same "sword" and hold it by the blade (the stick). Now keep it vertical and move it up and down...(so that the dumbell is moving ONLY in the vertical axis. Feels fine? Good...

Now try to swish it around like you did when it was reversed. Feels fine?

Again...does it feel ok? easy?

I hope that explains what I am trying to say about the weight distribution in the vertical axis...and the center of gravity.

Center of gravity of these bikes is affected by:

* rider weight
* fuel tank : fuel levels and tank positioning
* weight distribution of the bike without the rider

It is considered ideal to keep the CG as LOW as possible on the vertical axis. How you position the CG in the horizontal axis (along the bike's length) will affect handling without impairing stability too much.


Harsh bumps are transmitted to the rider more so on the lightweights but have noticeably less effect on the overall stability and shake.[/QUOTE]

This is just a measure of the performance of the suspension. I think you are wrong with this one - if the suspension is transmitting the bumps to the rider then it is CLEARLY not doing it's job. A harsh bump could mean a foot slipping off the pegs, jab on the front brakes by accident, roll throttle abruptly...

None of which are "pleasant" scenarios. A heavier bike with a well set-up suspension will absorb these bumps in a straight line. Cornering wont be as acute as the literbikes but that is clearly not the design focus of the Busa so it is a moot point. I know for a fact that modern liter bikes will run rings around the Busa on twisties.


If you have ever come close to dragging your knee around a corner on a Busa, you know that the bike has a tendency to wobble and in some cases, quite violently -- enough to scare the living crap outta you[/QUOTE]

Read the "dumbell stick sword" analogy.


Shifting hard at 10K under full throttle on the Busa, I get some rather interesting TQ steer and again on the 1000's, much less so...[/QUOTE]

Time to get your wheel alignment checked and your wheel/tyres balanced. These are the only conditions under which you will experience throttle steer on a motorcycle. This is dangerous sh!t...especially if you do track days. Get it checked before you take a spill...


Unless there's a fantastic concept of torque steer on bikes that's different than the one that does and can only apply to front wheel driven (and to a lesser extent, all wheel driven) cars, I'm done listening to you.[/QUOTE]


Torque Steer is a physical phenomenon. What he is experiencing is just a mechanical maladjustment. Thankfully MSF teaches riders to apply front brakes AND rear brakes at the same time. Applying rear brakes ONLY on a bike with an alignment issue is a recipe for disaster...

I know...I own a 1962 Royal Enfield Bullet 350cc bike with rear wheel alignment sprockets. That bike had no front brakes (it had the hardware but the bike was waaaay too heavy to stop with those measly drum brakes) and I used ONLY the rear brakes on it for several years...never crashed - came close on several occasions...had 10 foot skids because of bad alignment and tyre balancing...

But I never crashed.

Bring on the wobbly busa
guns.gif




<!--EDIT|gsferrari
Reason for Edit: "spelling :("|1125413589 -->
 
wow...this has become a lot of reading for me. Still trying to figgure out what I learned.
tounge.gif
 
Its a fairly believable picture. Shame that all manufacturers these days always seem to try and make each bike look like another. I personally don't like it, its got none of the character of the original.:(
 
P.S. The 06 GSX-R1000 sits WAAAAAY nicer with the seat just a TAAAAAAAD lower than where it was before which, to me, helped me feel a little bit more stable (CG thing there gsferrari?)
 
([pD said:
CerealKiller @ Sep. 17 2005,12:43)]P.S. The 06 GSX-R1000 sits WAAAAAY nicer with the seat just a TAAAAAAAD lower than where it was before which, to me, helped me feel a little bit more stable (CG thing there gsferrari?)
You will always have more stability if you sit lower. But lowering the seat is different from lowering the suspension. Handling will be severely affected (it can go both ways depending on the bike) if you lower / raise the suspension.

CG comes into play with bikes because the rider is a HUGE portion of the equation when you are calculating moments, forces etc. The rider's weight is not "negligible" as far as cornering physics are concerned. Not the same case for 4 wheel vehicles...

Sometimes I dont think it is really an advantage to be a featherweight either. Remember - a motorcycle does NOT like to be on it's side. The gyroscope behavior will force it vertical...it is the rider's mass and countersteering that brings about the lean that makes it possible to negotiate corners at speed.

I think there is an ideal rider position that changes with the weight. A lighter rider benefits from sitting up higher because that gives him more "moment" to use his mass and lean the bike into the corner. If he was sitting too low - the bike wouldnt lean very easily.

A heavier rider sitting too high has the opposite effect - the bike wants to fall in - you are forced to try to corner faster so that your "centrifugal" force keeps the bike from keeping over - often you will end up overcoming the grip from the tire and end up in a low/high side crash.

Heavier riders - go low
Lighter riders - go high

If anyone has a different take on this - please share - I love physics but i could very well be wrong about this.

gs
 
Back
Top