Just because your inclinometer gets a certain reading while going around corners does not mean this is the angle you are tilting your vehicle to. When you go around corners, there is a "centrifical force" that acts on things and pushes them to the outside of the circle
Exactly. Except the body is not "tiping" when going around the corner, but the total effect is essentially the same as a static tilt. I've also had it right around 30 off road but I don't have time to check it as easily as a smooth, paved corner. I just have a better feel for how fast I can negotiate a corner and the inclinometer reading is fairly stable so I can get an idea of how far I dare to take it.
This is one of my personal favourite "tilting" pics!.....It's was taken by a professional photographer (Michael Ellem of Offroad Images), whilst he was getting some pics of my Pinny for a Australian 4WD magazine article.
I never realised it was on such an angle till I saw the pics at the bottom of the hill.
I also rolled my Pinz, - just one more time over that little bitty hill -, too far on the left and gone...
Can't say I've ever rolled a Pinny..... I guess 30 years of driving Haflingers has honed my skill to try and keep the shiney side up!
I have rolled Haffy's plenty of times though!
Just because your inclinometer gets a certain reading while going around corners does not mean this is the angle you are tilting your vehicle to. When you go around corners, there is a "centrifical force" that acts on things and pushes them to the outside of the circle
Exactly. Except the body is not "tiping" when going around the corner, but the total effect is essentially the same as a static tilt. I've also had it right around 30 off road but I don't have time to check it as easily as a smooth, paved corner. I just have a better feel for how fast I can negotiate a corner and the inclinometer reading is fairly stable so I can get an idea of how far I dare to take it.
Jim M.
i am a bit skeptical about this. I am going to find my old physics teacher to confirm. Can you explain this phenomenon via vectors or math. I have been thinking about this for a while.
AZ_Dave wrote:i am a bit skeptical about this. ....... Can you explain this phenomenon via vectors or math. I have been thinking about this for a while.
hehe... my thoughts exactly. somehow i can get a grip on the answer to this.
the force on the ball in the guage is always exactly its weight. there is no other force on the ball in a static tip of the pinz. tip the pinz at any angle and that force is the same - the ball's weight.
uh oh... i need some breakfast.
1973 710m
"it is not in the best interest of the shepherd to breed smarter sheep." ~ author unknown
press any key to continue or any other key to quit. ~author confidential
Won't try to explain the centrifugal force effect on the gauge.
What is a very real factor is your effective CG outwards as the body leans. The more you tip, the less stable the vehicle dynamics. It's more than just CG, it's the triangle made by the CG's downward force & centrifugal force acting and the outside wheel. (Hard to explain in text)
Static, or going straight, the CG is one vertex, the road to cg the right angle of the triangle, and the wheel the other vertex. It's a right triangle, and the base is half the track and parallel to the road. You'll hear this sometimes called a stability triangle.
In a curve, the triangle is no longer right, as the CG vector shift toward the outside wheel. As the vehicle starts to tip, the CG moves even closer to the outside wheel, and the "base" component narrows, and it becomes even less stable. Higher CG, narrower base=less stable. And vice versa.
All that said, there is a nice diagram in the duece & a half drivers manual that shows this. Maybe prof pinz can get us a nice diagram?
And regarding pinz flips..... most have nothing to do with static tip angle. The rear end get's light going down a hill, the driver panics, slams on the brakes. CG shifts forward due to inertia, it tips more, they brake more. With the rear up/light, the slightest side camber starts to bring the vehicle over.
Fix? If you start to feel the rear get light, hit the gas. It shifts the CG back, the rear comes back down, and you are (temporarily) back in control. Geesen put me onto this, and he's right. It's saved me many times. Counterintuitive, but it works.
Better yet, never brake hard on a steep hill, never put the clutch in on a down hill, and don't let speed build up that would force you to brake quickly.
I'm not sure I've ever seen a case where a pinz flipped going up a hill. Sean or Vince one flipped one at speed in a turn in a rally, that was a different case for sure.
thanks for the answer Alan. I understand this all really doesn't matter in the grand scheme of things, (it is going to tip when it is going to tip), but I find the why questions about things the most interesting. Didn't think about them tipping forward. maybe we should do a poll to see how people tend to roll and in what conditions. It would be interesting to know which conditions are the main culprits.
