Why Are Torsion Bars Handed?

[allanallen 528 2 Cars]

why do peugeot have different part no.s for left and right torsion bars? is there a difference?

 

I know they're originally marked differently to each other (2 lines for left, 1 line for right) but surely theres no actual difference.....is there

[RossD 44]

No difference as such as far as I can tell, apart from the paint rings on the bars determining left and right sides. Unless there is a difference in the actual make up of the metal, who knows!

[Powers 13]

Its the direction of the coil running in the bar.

You want the load from the suspension to push against the spring not to pull it.

[engine killer 6]

Its the direction of the coil running in the bar.

You want the load from the suspension to push against the spring not to pull it.

 

 

Sorry i am a little dumb here, from my understanding the torsion bar is a solid bar which when it is under pressure (the arm twist it in a circular direction), the load twist the bar. Does it matter which direction?

[skeggyrik 3]

Its the direction of the coil running in the bar.

 

???

[Tom Fenton 1,541]

The coil running in the bar? I have not heard of this.

[Jrod 7]

I've always seen it as if you twist something one way, then if you put it in the other way and twist it the other way it can't be good for it. Maybe its just so they always twist the same way?

[Veero 1]

The coil running in the bar? I have not heard of this.

 

Eh? Coil? It's just a solid steel bar.

[dirtdog 4]

i dont have a clue about this so no laughing, pointing, or ridiculing, but..how else would you get a spring rate from the rear without springs?

[engine killer 6]

Sorry for hijacking the thread, what about the behaviour about coil spring? what is the energy needed to compress a coil by 1 inch and stretch it by 1 inch? will there be any difference? a coil spring is actually coiled from a piece of long and thin steel bar, in order to deform it either way, should the energy be the same?

[Pugnut 9 1 Cars]

i dont have a clue about this so no laughing, pointing, or ridiculing, but..how else would you get a spring rate from the rear without springs?

the trailing arm is used as leverage on the torsion bar to twist it. obviously the spring steel wants to return to its natural position

[Veero 1]

Yes the entire "spring" if you like, is all in the torsional twist of the bars. There are no actual "spring" springs on the rear suspension on the 205.

[engine killer 6]

i dont have a clue about this so no laughing, pointing, or ridiculing, but..how else would you get a spring rate from the rear without springs?

 

 

i guess the arm also play a very major role here, leverage? the longer the arm (away from the tb), the weaker the spring rate? to twist a bar, the bar will deform but it will reprocess to its original shape when the force no more applied to it. by measuring the force needed to move/pull the end of the arm by a certain distance, can we compare it to coil spring when a spring required the same effort to expend for same distance?

[jackherer 543]

There are no actual "spring" springs on the rear suspension on the 205.

 

Yes there are, torsion bars ARE springs, just not COIL springs

 

A coil spring is just a torsion bar in a coil shape, when you compress a coil spring the entire coiled up bar is twisting along its full length, just like a torsion bar does.

[pug_ham 244 3 Cars]

I've always seen it as if you twist something one way, then if you put it in the other way and twist it the other way it can't be good for it. Maybe its just so they always twist the same way?

This is the reason behind why I think they are handed also.

 

If you swap them from left to right or viceversa you are 'winding' them in the opposite direction which won't be a good thing.

 

Maybe that explains what happened to the car in this topic.

 

Graham.

[Pugnut 9 1 Cars]

This is the reason behind why I think they are handed also.

 

If you swap them from left to right or viceversa you are 'winding' them in the opposite direction which won't be a good thing.

 

Maybe that explains what happened to the car in this topic.

 

Graham.

 

so your saying that a poorly adjusted air bleed screw caused torsion bars to snap?

[Powers 13]

Yes there are, torsion bars ARE springs, just not COIL springs

 

A coil spring is just a torsion bar in a coil shape, when you compress a coil spring the entire coiled up bar is twisting along its full length, just like a torsion bar does.

 

Thanks for clearing that up for them. Maybe I should have added that to my original post!

[pug_ham 244 3 Cars]

so your saying that a poorly adjusted air bleed screw caused torsion bars to snap?

Well they are french but even that'd surprise me.

 

Link edited.

 

Graham.

[Veero 1]

Yes there are, torsion bars ARE springs, just not COIL springs

 

That's what I meant

[allanallen 528 2 Cars]

I've always seen it as if you twist something one way, then if you put it in the other way and twist it the other way it can't be good for it. Maybe its just so they always twist the same way?

 

good answer

 

theres no difference in the bars as such then? must just be peugeot giving things different part no.s for no reason

[maxi 36 1 Cars]

good answer

 

theres no difference in the bars as such then? must just be peugeot giving things different part no.s for no reason

 

 

Yes, there is a difference in the bars. Im pretty sure the torsional strength and spring rate in them only works twisting one direction. What you have to bear in mind is the splines are pitched differently at either end, so a right hand side bar wont fit a left, are you with me???? (Thats the way I understand it anyway)

 

Maxi

[allanallen 528 2 Cars]

What you have to bear in mind is the splines are pitched differently at either end, so a right hand side bar wont fit a left

Maxi

 

surely this just means you can't spin the bars through 180degrees, you can still swap the bars round or in fact use 2 left hand bars in a beam?? (sorry if ive got the wrong end of the stick maxi)

 

and i cant how the torsional strength and spring rate in them only works twisting in one direction, surely they would need to be made of some magical material for this to happen? now i'm confused

Edited September 5, 2008 by allanallen

[maxi 36 1 Cars]

One one to try it, get a rear beam, turn the bars around (or attempt to) and then take it for a drive. I think it will be quite an experience!!

 

Or im completely wrong and I should get my coat.

 

Maxi

[Rob Thomson 6]

From what I know about spring steel (which isn't all that much) it's just like most other materials in that it will have exactly the same properties if twisted either way when new. But I think its properties can change with use.

 

As an example, my mates with Mk2 Escorts keep their spare half-shafts labelled with 'left' or 'right' because - they reckon - they're much stronger in the direction they've been used in before. I guess the same could be true with the Pug's torsion bars.

 

I can't see why the TBs would be given different part numbers when new, though.

Edited September 5, 2008 by Rob Thomson

[allanallen 528 2 Cars]

One one to try it, get a rear beam, turn the bars around (or attempt to) and then take it for a drive. I think it will be quite an experience!!

 

Or im completely wrong and I should get my coat.

 

Maxi

 

i've got a feeling i have done several times. i've fitted a few bars to beams which either have no marks or have been painted so they could of been fitted the opposite way to what they were originally. never noticed anything serious though. christ knows, i'll just try to fit them back on the same sides i took them off in future.

 

i'm sure theres no difference in the bars when they're new though