Hi all,

Looking at making up my lower wishbones shortly for my midi locost, couple of questions on rose joints if I may;

1. M12 or 1/2.... Any preference or advantages
2. Left and right handed threads, would I use left hand thread on left hand bone and right on right hand side? Does it matter??
3. What typical load ratings should I be looking for? Assuming I havnt calculated in any detail the forces involved, is there any rules of thumb I could use?

Regards, Rob

I used 1/2", these are larger than the ones on the rear of Westfield IRS suspension, my choice was based upon price from McGills, also my brackets were already drilled to 1/2".

Right hand/left hand if you want to make a simple adjusting rod like a Panhard rod the use a mixture at either end, otherwise just standard right hand for ease of replacement.

The weak spot will probably be where you butt pre drilled and tapped plugs into wishbone tubes, fish mouth the end to increase the size of the weld.

Regards Mark

[Edited on 2/1/13 by mark chandler]

I was told to have one left n one right on each side not sure why but that's way I did.

[Edited on 2/1/13 by jossey]

For an adjustable tie bar you would have this, just knock off the lock nuts and twiddle the bar

If a joint at only one end then just use RHS threads.

As above,

Use Right hand threads unless its for rear lower, which sometimes may put in an adjustable bar to adjust toe? then obviously LHT and RHT on each end.

The norm on club racing cars like RGB is 7/16 thread, we tend to use 7/16 bore as well and then top hat down to 8mm.

Thanks guys, that helps me a lot.

I have looked at the McGills stuff, so I presume that's a recommended source of bits?

My lower arms are going to be of two piece, the A arm it's self and a tie bar, so the rose joints are for that part of it. Will go for Right hand thread on the A arm and a combo on the tie bar. Also running inboard suspension at the front so that will be the same set up.

Thanks for the advice.

Regards, Rob

One thing I feel is worth a mention is the pitch of the thread.

The finer the thread the more precise the adjustment of track and camber,
particularly for rear bones as there's usually no track rod ends.

Front bones with inner rod ends will also adjust castor, as screwing one in and
the other out will move the outer joint backwards or forwards.
IMHO a much neater solution than rows of washers.


Just a thought.
Paul G

Make sure you list all the bits in the plans mate

Mine are all 5/8 thread, 1/2 bore,
Not saying mines right or wrong (designed by SHP) but something to consider maybe

[Edited on 3/1/13 by blakep82]

And all the shock mounts and rose joints on my MNR were 1/2" bore as well.

Hi Chaps,

I have a chest infection at the moment which is going to stop me going in the garage at the weekend.

But I am going to draw up the arms over the weekend, taken some measurements, i will check out load ratings of 5/8" and see what the difference in cost will be, I'm using 25mm CDS Tube so which fits that best probably is the way to go.

Cheers, Rob

Ordered my rose joints today, went for the Teflon coated versions in a 1/2" size, basically the 5/8" would be to big for my tube.

The guys at McGill Motorsport are very helpful.

Rob

Ordered my parts yesterday from McGill Motorsport.

Arrived today! Very pleased with the bits, very pleased. Now back to the design work. 😛

Rob