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Wishbone Design
Mix - 4/11/04 at 10:39 AM

My lower rear wishbones will probably end up looking like one of these designs. Is one more suitable than the other and if so why?

Cheers Mick

And if anybody could tell me how to get the drawing itself into the topic I'd be very grateful

[Edited on 4/11/04 by Mix]


JonBowden - 4/11/04 at 11:30 AM

If you can convert the picture to a .jpg or .gif file, it should be easy.
To attach, click the eigth button from the left on the posting form


Mix - 4/11/04 at 03:16 PM

Son to the rescue, (I hope)

Like this

Mick

[Edited on 4/11/04 by Mix] Rescued attachment wishbones.JPG
Rescued attachment wishbones.JPG


Peteff - 4/11/04 at 04:25 PM

They just look like the same one turned over.


locoboy - 4/11/04 at 04:31 PM

in my unqualified engineer status i would say the one on the left.

Why......... because i think the rear bones will have most of the load applied from the front pushing to the back, and the one on the left has the bracing in the right place for that...............



come on punks..................shoot me down in flames


JoelP - 4/11/04 at 10:00 PM

ok col! surely the one on the right is better, as the biggest force on the bone is the wheel pushing the car forwards?! braking force will be less on the back wheels, i wold guess...


pbura - 5/11/04 at 12:34 AM

Looks like Joel's right! Here's a pic from a Leitch:


Mix - 5/11/04 at 09:32 AM

Pete
They are similar but not the same. My question related to the position of the brace in regard to the direction of travel as Col and Joel picked up. A bit more searching on here and I've found that Luego bones are as the desgn on the left and MK ones as per the right so at the end of the day it may not be that important. I'd still be interested if anybody can offer reasons to prefer one design over the other.

Cheers Mick


Bob C - 5/11/04 at 10:13 AM

your biggest force will be hitting a kerb or pothole (think 1/2 ton hammer travelling at 70mph.....) Do you want the diagonal brace in compression or tension when this happens. My gut feel is compression as this is less reliant on the welds quality but I think it's pretty academic.
cheers
Bob C


Spyderman - 5/11/04 at 11:45 AM

First of all it will depend on your uprights!
Secondly will the applied impact force being resisted be in the line of travel or in a sideways motion?
If the force is in line of travel then the triangular brace needs to be at the front, as in left image, but either way will be good.
However the impact forces applied to the tyre will try to rotate the upright (unless there is sufficient wheel backspace to make the pivots central) and apply compression to rear arm and tension to front arm. In this case you would want to put triangular brace to the rear arm.
Hope this isn't as confusing as it seems to be trying to explain it!

Either way should be good and as said above will mostly depend on upright and available space!

Terry


[Edited on 5/11/04 by Spyderman]


Bob C - 5/11/04 at 01:01 PM

Couple of points:
first I can't help feeling that if you clobber something while going sideways, you'd expect something to break! You hit potholes while going forward all the time.
Second, while going forwards no torque is transmitted to the upright, only brakes can do this, motoring torque is reacted to the differential. Leaving you, I guess, with both wishbones sharing the fore/aft impact depending on distance from axle centre to that wishbone pivot.
cheers
Bob c


JoelP - 5/11/04 at 10:35 PM

quote:
Originally posted by Bob C
Second, while going forwards no torque is transmitted to the upright, only brakes can do this, motoring torque is reacted to the differential. Leaving you, I guess, with both wishbones sharing the fore/aft impact depending on distance from axle centre to that wishbone pivot.
cheers
Bob c


the force of acceleration is felt by the wishbones too. not as toque but as a simple push.