Cruser meets Van

**Danae** · 17th August 2009, 23:52

It's a "ba dum dum tschhhhh"

**skidMark** · 17th August 2009, 23:58

Originally Posted by metalhead

so im riding dow Gt North rd in the bus lane, doing everything perfectly legal for a change and im just coming up to moa rd when heading in the opposate direction is a van that happens to decide to turn into the space i am about to occupy, all i can think as im breaking and swerving to try avoid it is "Oh no, not again".
i dont remember the actual impact, but the next thing i know im throwing myself off the ground befre i have stopped rolling down the road yelling my head off. fuck it was funny

anyway, this is the damage XD i was impressed

Ouch!

I used to assemble these bikes and others for lifan NZ, go talk to jason who imports them if ya not insured, say you know mark and he may do you a better deal, i can put all the bits on for ya, just cover the gas for the cage to get to your place or pick up the parts if need be.

www.lifanmc.co.nz

**skidMark** · 18th August 2009, 00:02

Originally Posted by motorbyclist

actually what with all teh shear, this does happen... more interesting is the triple clamp..... wonder if a jappa would have done that?

Seen MANY a japper do the same thing and worse dude, had a good crawl over "mynameis" 's zxr after hitting a car in a similar way, top of clamp was broken right off the fork etc, its a hell aof alot of force and i'm actually impressed with how well the lifan has handled this impact.

EDIT:

Found i couple of pics of afore mentioned zxr...
http://www.kiwibiker.co.nz/forums/at...0&d=1179706754

http://www.kiwibiker.co.nz/forums/at...2&d=1179706754

in the 2nd one you can see the top of the fork clutch side where the triple clamp is meant to be and severe fork twist lower down, standard stuff for a t bone really

**motorbyclist** · 18th August 2009, 02:28

Originally Posted by Real_Wolf

Its actually more torque and angular momentum, which works slightly differently.

The faster you ride, the more angular momentum you carry and the larger the torque thats required to cause you to change direction

worst explanation ever

Originally Posted by ital916

full fairings very rarely act like sails.

The reason faired bikes get blown around a little more is they have a larger cross sectional area on the side.

which makes them act exactly like a sail

3rd form physics is fairly easy to understand. aerodynamics isn't. thus we do basic explanations that are fundamentally correct instead of thoroughly confusing everyone.

**jono035** · 18th August 2009, 06:34

Originally Posted by motorbyclist

3rd form physics is fairly easy to understand. aerodynamics isn't. thus we do basic explanations that are fundamentally correct instead of thoroughly confusing everyone.

And there we have one of the principal abilities of an Engineer.

**ital916** · 18th August 2009, 09:23

Originally Posted by motorbyclist

worst explanation ever

which makes them act exactly like a sail

3rd form physics is fairly easy to understand. aerodynamics isn't. thus we do basic explanations that are fundamentally correct instead of thoroughly confusing everyone.

Sigh andrew, you are not right all the time and dont make fun of engineering. There is a point in time when your theory spouting nonsense must come to an end. Don't use equations to try confuse people.

And no sails do not operate as wind catchers..well they do but you wont go anywhere fast, when properly utilised they will operate as a airfoil or in laymans terms a wing.

I dont know what sort of engineer you hope to be buddy but i like to do in depth calculations before finalising anything. There comes a point where third form maths doesnt cut it anymore, we were taught basic physics equations to acquainted with the field of physics. Fundamental equations very rarely can be used by themselves to correctly explain a situation. Its why we dont go if we apply a 10 newton force to a 1 kilogram object it will travel at 10m/s for eternity. Fundamentals do not give an accurate picture.

You shame engineers....you will be banished from our secret society.

...who keeps the martians under wrap....WEEEE DOOOOOOOOOO!.....

**ital916** · 18th August 2009, 09:29

Originally Posted by jono035

And there we have one of the principal abilities of an Engineer.

No the principal ability of SOME engineers is to try and bullshit their way through projects by thinking they know it all.

I dont know everything as a mechanical engineer. If I need electrical theory ro work done I will come to you, an electrical engineer.

See the problem with andrew is he is mechatronics. Where they try to be both a mechanical and electrical engineer. Just teaming up a mechanical and electrical engineer specialized in their respective field would be far more productive.

**PirateJafa** · 18th August 2009, 09:31

Originally Posted by ital916

And no sails do not operate as wind catchers..well they do but you wont go anywhere fast, when properly utilised they will operate as a airfoil or in laymans terms a wing.

Err yes some of them do - and it's with them that your generally manage to attain your top speeds.

And for the record, I'm not a physicist, I'm not a engineer, but I am a sailor.

**Danae** · 18th August 2009, 09:58

A mathematician, a physicist and an engineer are trying to prove the hypothesis that all odd numbers are prime numbers.

Mathematician: "1 is a prime number, 3 is a prime number, 5 is a prime number, 7 is a prime number, 9 isn't a prime number. The hypothesis is false."

Physicist: "1 is a prime number, 3 is a prime number, 5 is a prime number, 7 is a prime number, 9 isn't a prime number, 11 is a prime number, 13 is a prime number...well let's see, that's 7:1 against, so the hypothesis is true."

Engineer: "1 is a prime number, 3 is a prime number, 5 is a prime number, 7 is a prime number, 9 is a prime number..."

Ta daa!

Bikes act as sails. Proof:

**skidMark** · 18th August 2009, 11:34

How did a

"i crashed my bike"

thread turn into a

"i am the better lecturers pet"

thread?

**StoneY** · 18th August 2009, 11:46

Originally Posted by bomma

van: 1, cruiser: 0..........when's the rematch??

Debateable- we aint seen how stoved the Van is!
When my mate hit a van on my old gsx 1100 es (83) he ripped the whole cab off the van

Was only at 80kmh too- was the older type C20's from the 80's- tin cans- bike won that round

I dont let mates borrow my bikes anymore

**Ixion** · 18th August 2009, 11:54

Originally Posted by ital916

full fairings very rarely act like sails.

The reason faired bikes get blown around a little more is they have a larger cross sectional area on the side.

But - von Klunken has about the largest , most slab sided fairing ever on a motorbike. Yet, it's the most wind stable bike I've ever owned. How come?

Whereas ffwabbitt with no fairing at all is quite bad . maybe not the worst I've ever ridden but up there.

It's more complex than just the area of the fairing.

Originally Posted by motorbyclist

worst explanation ever

which makes them act exactly like a sail

.

Not really. A sail relies on having higher pressure on one side than the other. Is there any evidence that a motorcycle fairing, side on , has a pressure differential.

**Real_Wolf** · 18th August 2009, 12:24

Well if it blocks the wind from going through then yes, it would, but at the same time so would a nekkid.

Anyways, the simplest way to think of it is as a lever, you have the wind acting as a force on the pivot, which is the ground-wheel connection, and the more force that is applied on the side, and the higher it is applied, the greater the torque applied.

Then you put in that angular acceleration (bike falling sideways) is relative to the torque, more torque, bike falls over faster.
However, the heavier the bike, in terms of angular mass (which is proportional to the height the center of mass is from the pivot) will change how this angular acceleration occurs.

Finally, a greater cross sectional area means that there is more space available for the wind to put pressure on, and as such it can have a greater effect.

This is all very simplified physics though, and as such the intracacies of the shape of the fairing, and just how it diverts the wind will have quite an effect.

For example, if its just a solid wall fairing, no curvature at all, ignoring the fringe effects of the 90 degree corners at the side, you will get the full force applied upon the fairing in the direction of the wind, assuming wind is at 90 degree's to the fairing surface.

However, if the fairing is curved, then the wind is merely diverted, and the force that it applied is proportional instead to the diversion of the wind, which will be less than the full force. The more the wind is diverted the more 'pushing over' force you will end up having.

Either way, due to the difficulty of dealing with turbulent air and its equations, one has to assume that the wind in question has a laminar flow which doesn't fit the actual model of what most people call "the wind pushing over my bike"