Radius arm drop plates

[Howard Wright]

Hi All

I’ve acquired a bowed axle and am now thinking about dropping the radius arms. Chris Gould shows a good diagram in his book on reproduction Ulster’s but the plate thickness (1/4”) seems a bit heavy to me.
Particularly as I intend incorporating shackle immobilising in the same plate.

Is 1/4” plate normally used and how do you prevent this plate and the radius arms from rotating about the axle. Is it down to friction alone?

Cheers

Howard

[Steve Jones]

Yes and yes. Mine have been tested to extreme (landing on one front wheel as the car exited a roll) and survived, in place, to tell the tale. Just ordered the metal to make another pair for another, long term, project.

Steve

[Alan]

It doesn’t have to be friction alone- mine has ties between the lower hole where the radius arm fits and the damper mounting. If they are going to move it tends to be outwards so a bit of 16SWG sheet in tension has worked for over 40 years. On the other hand, another car I have doesn’t have ties and that’s been ok for a similar length of time. Depends if you wear belts with your braces.

[Ruairidh Dunford]

Howard,

Tod writes:

"Howard
This is what I fitted to my special, I made them from 1/8" miles steel plate. They anchor between the damper mounting and the drop link.

Tod"

   

[Howard Wright]

Excellent help guys 

I’ll order up some plate.  I’ve decided to extend the plates up to the spring eye on the axle. On one side this will allow me to immobilise one end of the spring as well as positively locating the radius arm.

On the other I will need to make up longer shackle pins to fit the shackles outside the plates and spacing washers between the spring eye and shackle. Comments please!

Thanks again for the help

Cheers

Howard

[Zetomagneto]

Howard, on the fixed end you don't have the shackle plates, your plate which is fixed has the shackle
pins coming through it so no need of longer pins.

One way of doing it here http://www.da7c.co.uk/technical_torque_a...ations.htm

[Howard Wright]

Hi Zeto

Yes I realise that on the fixed end but on the other free end I had also intended to extend the drop plates up to the spring eye on the axle to locate the radius arm. It may be easier to use a strap to the shock mounting.

Cheers Howard

[Lowespeed]

Hi Howard,
Ithink Tony Leslie at Holmesdale Sevens still does the gun metal castings of the original ends for sports axles which you can hold on with high tensile bolts if you don't fancy hot riveting

[Dave Wortley]

It’s possible to reproduce the original rad arm ends by fabricating and welding up from mild steel plate. I made some for my Ulster rep 27 years ago. Still ok after a fair amount of miles. Road miles, not racing or trials. Shouldn’t take much longer to make than the 1/4” steel drop plates.
Dave.

[Zetomagneto]

Compound Curvatures used to do fabricated ones that looked good.
Are they still going?