guest[b][user=64][size=1]castrolrob[/size][/user][size=1] wrote: [/size][/b][quote][size=1]regarding front roll bars most of them operate on a twist system or, as can be termed,torsion.roll bar is its function-not its name.if in any doubt about this,corsas for example,you order the front rollbar brackets/bushes etc(you know,the ones that fracture)and you will receive from the manufacturer TORSION bar mounts/brackets.
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[size=1]I quite agree with most of what you have said:), but when you said “Roll Bar is its function – not its name, on this point we seem to differ, may I explain this another way;
The Ford Maverick 4 x 4 has independent front suspension, on each side at the front is a Torsion bar secured to the vehicle body and secured to the front lower suspension arms. The Torsion Bars are loaded such that when the wheel is hanging freely, the load (torque) through the Torsion bar forces the lower suspension arm downwards towards the road surface, the road surface creates a normal reaction force which pushes up against the road wheel. The Torsion Bar therefore is constantly loaded in use even when not being driven.
The Antiroll Bar.
These are fitted across the axle of any vehicle they are fitted to, the Vauxhall Corsa rear axle does not incorporate a antiroll bar, that is a torsion bar welded in. The antiroll bar reacts in use from the road surface imperfections, each time the road wheel has an upwards thrust force, the antiroll bar is placed into a torsional moment.
I will try to explain it as follows;
[font=”Century Gothic”]The Anti-roll bar fitted across the front is not in torsion when the vehicle is not in use. My understanding of the operation is that when the vehicle is in use cornering, the centrifugal force acting through the centre of gravity of the sprung body produces an overturning moment created by its offset to the body’s roll centre which will therefore tend to make the body roll. The body rolling will tilt the transverse span of the roll bar with it so that the cranked arms on the outside wheel to turn will be depressed downwards, whereas the cranked arm on the opposite end near the inside wheel to the turn will tend to rise.[/font]
[font=”Century Gothic”]The consequence of the misalignment of the antiroll bar arms is that the two cranked arms will rotate in opposite directions to each other and so transmit a torque from the inside wheel which is subjected to less load to the outside wheel which is now more heavily loaded. The effect of the torsional wind up in the bar is that it tries to rotate the outside wheel cranked arm and since the arm is attached to the axle or indirectly to the wishbone arm it cannot move. [/font]
[/size][font=”Century Gothic”][size=1]Now although the forces acting on each type of bar are the same, there must be a difference in name, otherwise when purchasing a bar for a vehicle, the parts department must be able to distinguish between a Torsion Bar, and a Antiroll Bar. [/size][size=3] [/size][/font]
