TA torque reaction-not!

[yoshi]

well i'm glad I haven't told that to anyone, lol. I saw how street bikes worked, and since the back end lifted up on the first rail I built, I put 2 and 2 together and forgot that the bearing isolate the wheel from the trailing arm, different than a streetbike setup, I never mentioned it to have anyone correct me, so i've thought that was the reason for years now, lol..

Realizing there are bearings separating them, I can't believe I ever thought that, but I guess I didn't know hardly anything when I started.....

[masterfabr]

Yoshi,I gotta pat you on the back. It takes a big man to admit you've had the wrong understanding for a long time.Just shows that WE ALL can learn something every day.BRAVO!

[nutz4sand]

I understand that its the arm trying to push up the chassis that is seen as torque reaction by some. But its just a jacking effect. If you had HUGE 44 inch tires with the arms going downward to the chassis it would want to shove it downward. In some wierd kinda build.

The longer the arm the less jacking thus Trophy trucks seem to do it less. The arm angle plays more part than the length though.

Even watching two seperate buggies by the same builder the buggies that sit higher do it worse due to more angle in the rear trailing arms. (easy to see this on Funco as the air suspension height can be tailored from the drivers seat and some ride it as tall as they can for "show" while others run it in the midrange to allow for a better droop feeling in the rough.

I would wager that the shocks also play a huge part in thier valving in if they allow it to lift a little or a lot. Some machines transfer their weight backwards so quickly they can make it seem like they have little to no lift.


To chains drives:
Polaris chain drive quads have a skinny tranny that fits inbetween a wide swingarm (Scramblers do anyways) The trannies output sprocket is then RIGHT on the swing arm pivot. This is supposed to help eliminate the jacking effect the chain causes and also make it so the adjustment stays truer thru the swingarms arc. Even with that If I sit over the bars on good traction (the street) it trys to jack up and push the machine upwards. If I sit on the back (I wiegh 280 pounds. Give or take 5 depending on dinner) Its swingarms is not at much of an angle and it does not seem to try to lift the machine but with my butt on it it will wheely pretty easy... Go fig.

I still wonder if you could put the power to the front of the swingarm right above the pivot (and still allow for free movement) if the torque effect would not be near as bad (minimilized) then ran the power via a chain to a sprocket on the rear tires spindle. Bill

[masterfabr]

Originally Posted by nutz4sand

I understand that its the arm trying to push up the chassis that is seen as torque reaction by some. But its just a jacking effect. If you had HUGE 44 inch tires with the arms going downward to the chassis it would want to shove it downward. In some wierd kinda build.

The longer the arm the less jacking thus Trophy trucks seem to do it less. The arm angle plays more part than the length though.

Even watching two seperate buggies by the same builder the buggies that sit higher do it worse due to more angle in the rear trailing arms. (easy to see this on Funco as the air suspension height can be tailored from the drivers seat and some ride it as tall as they can for "show" while others run it in the midrange to allow for a better droop feeling in the rough.

I would wager that the shocks also play a huge part in thier valving in if they allow it to lift a little or a lot. Some machines transfer their weight backwards so quickly they can make it seem like they have little to no lift.


To chains drives:
Polaris chain drive quads have a skinny tranny that fits inbetween a wide swingarm (Scramblers do anyways) The trannies output sprocket is then RIGHT on the swing arm pivot. This is supposed to help eliminate the jacking effect the chain causes and also make it so the adjustment stays truer thru the swingarms arc. Even with that If I sit over the bars on good traction (the street) it trys to jack up and push the machine upwards. If I sit on the back (I wiegh 280 pounds. Give or take 5 depending on dinner) Its swingarms is not at much of an angle and it does not seem to try to lift the machine but with my butt on it it will wheely pretty easy... Go fig.

I still wonder if you could put the power to the front of the swingarm right above the pivot (and still allow for free movement) if the torque effect would not be near as bad (minimilized) then ran the power via a chain to a sprocket on the rear tires spindle. Bill

Absolutely correct.

[dunerocket]

This is torque reaction on a TA, and there is no realistic way to eliminate it. It should be exteremly extremely small assuming you keep your bearings in good working order. Perhaps an electomagnetic bearing operating in a vacuum, but as I said no realistic way.

[masterfabr]

Originally Posted by dunerocket

This is torque reaction on a TA, and there is no realistic way to eliminate it. It should be exteremly extremely small assuming you keep your bearings in good working order. Perhaps an electomagnetic bearing operating in a vacuum, but as I said no realistic way.

There is not.Unless your talking bearing drag. C'mon think this through.

[K-fab]

Don't forget the parasitic drag from the seals. They'll induce torque into the trailing arms also.

But, the real world of it is that there is not enough drag via either the bearings or the seals to induce any sort of torque reaction into the arms.

[dunerocket]

I do think things through, it's what I get paid to do. People use terms that are extremely limiting without realizing the implication of their statement. To say that there is no (zero) torque reaction in a trailing arm is incorrect. Draw a free body diagram and you will see your error.

[masterfabr]

Originally Posted by K-fab

Don't forget the parasitic drag from the seals. They'll induce torque into the trailing arms also.

But, the real world of it is that there is not enough drag via either the bearings or the seals to induce any sort of torque reaction into the arms.

Ditto.I'll admit not zero but you gotta be kidding if anyone ,dunerocket,thinks it of ANY consequence.

[nutz4sand]

Originally Posted by K-fab

Don't forget the parasitic drag from the seals. They'll induce torque into the trailing arms also.

But, the real world of it is that there is not enough drag via either the bearings or the seals to induce any sort of torque reaction into the arms.

Would double sealed bearings be twice as bad?? J/K... But seriously

Dunerocket could you draw an example as you speak of to demonstrate what you are refferring too? Thanx Bill