Newer rear suspension wishbones

[JohnD]

It must be ten years ago that the Binman made me some new, light weight rear wishbones, to go with my new rear axle.    They have given stalwart service, been repaired several times ,but just recently both broke again, in the same places, and I realised too that the stress of the dmaopers had twisted them!      So I copied Jon's design, but in heavier metal.  Just fitted them to the car, and it's back on its wheels - with a rear camber, even after rolling the car to and fro, of more than -3 degrees!    I'll adjust them tomorrow, but very pleased with them.

As well as being heavier duty, they now include a cross tube.  It's difficult to see, in the pics, as it's above the main Wb, carries the damper bolt housing and the forces from that right across  to the opposite side on the radius arm joint tube.  I've left the damoper loose for now while I set up the suspension.

NB - MGF upright and disc brake.

Edited October 4, 2017 by JohnD

[rustbuckit2011]

Lookin good John!

Im impressed with those mgf links and the wishbone arrangement. Thinking about something similar with nissan pulsar gtir rear links as they are a bit easier to get your hands on in my country. 

Do your handbrake cables run from roto brackets or chassis guides?

[JohnD]

Can't remember!  Not without looking.   Would it help you to know?

John

[rustbuckit2011]

Im just curious to know whether its worth me bothering trying to find and fit the roto bracket handbrake guides to my rotoflex and discs conversion on a herald chassis.

I know that the effects of camber change on the h.b cable when used with the chassis mounted brackets wreaks havoc with the standard roto drums - Im wondering if mgf calipers (both the calipers themselves and their orientation on the link) are a little more forgiving 

Someone out there must have tried it- perhaps it deserves it's own thread

[Nick Jones]

I had this issue on my Vitesse as it is a Mk1 tub on a Mk2 chassis and thus had no handbrake guides at all when first built.

Not knowing any better at the time I welded swing axle chassis brackets in the usual place.  I also had to extend the levers on the backplates to bring the cable run out far enough to miss the doughnuts themselves.   This actually gave a very effective handbrake when everything was in narrow zone of adjustment and ride height.

However, small changes in suspension position had a big effect on cable tension so in order to prevent the brakes coming on  on every little bump it had to be set rather slack and even then you could feel the brakes coming on intermittently on bumpy roads.  Also, adding passengers or payload would affect things.....  Not acceptable.

My solution was to add a cable outer and not use the guides at all.  This took a bracket on the floor near the relay arm and brackets on the vertical links for the cable outer to act against, and these have to be strong and rigid.  There there is the cable...  Mine was based on a Fiat 127 one IIRC but had to be shortened, which was hard to do in an MoT acceptable way.  It's not perfect, it's is still affected by suspension position to a small extent (Cables possibly not quite long enough loops - working the length out is a right sod) but it's been working acceptably for best part of 30 years.  I am tempted to convert to discs from time to time (usually just after a track day or pass-storming session) but this would mean re-doing the cables, and so far I have not beyond having a lie down until the feeling goes away.....

 

Nick

[zetecspit]

I used "bowden" type cables. Actually the mgf ones with the MGF handbrake (which has exactly the same pivot points in terms of dimensions as the Triumph one)

On my spit, I drilled the double skinned/box of the heelboard and popped a plate on there, very simple. Once all callipers etc on, chopped the end off the inner cable at the handbrake end, then cut the outer cables to fit the car, then the inner ones. Then popped down to a local "wire rope" specialist who crimped threaded ends on for me (£10 the pair, bargain)

Onedownside with the spit is I discovered the cables fouled the very front on the inner wheel arch, and had to make alterations to the metalwork. And in hindsight, I should have used a lighter calliper (golf/polo/saxo or whatever)as lighter, and probably would have got one with a better cable location. Still, not swapping them now.

[Spit131]

You can make up simple adjusters to bring the cable arms clear of the bodywork .

[rustbuckit2011]

Hells teeth, that is great info- thanks guys much appreciated.  I'll let you know how I get on.

Spit131- those adjusters look well made, but Im afraid for the life of me I just cant work out where you fit them-

Do they fit on the pull lever, or between the outer cable arm and its respective mounting point changing the angle at which the cables lead from? If its on the pull lever then I guess having the pivot point further out makes your handbrake pretty effective to boot

I think I'll need to have a play with the parts and see about clearances on the herald body- I dont think it's quite as tight as on the spit which should make life easier!

[Spit131]

Sorry Rustbucket here is a picture of the adapter fitted under the arm . Matt

[rustbuckit2011]

Ah aha! Clever wee device that Matt- easier than bodywork- Cheers!