Front Suspension A Arms

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After a bit of welding, it’s always good to have a mock-up.
– At least I didn’t sit in it and make ‘brum brum’ noises.

Ignoring the hours spent doing the CAD work, plus those making the brackets, the front A-Arm mounts took me 10 hours to get in the right place.

There were:

  • 8 steel rules clamped to the chassis table,
  • 2 laser spirit levels,
  • 1 digital spirit level,
  • 2 bubble levels,
  • 4 set squares,
  • 12 welding clamps,
  • 2 verniers,
  • 9 G cramps,
  • 2 x 1 metre lengths of M12 threaded bar
  • Molegrips everywhere
  • Handfuls of shims
  • Dummy urethanes and roller bearings
  • etc , the list goes on.

I barely dare breath in case I knocked something and had to start over. Eventually, they only took me 10 minutes to weld into place.

Haynes Roadster Locost Front A Arms

I had to use my own suspension geometry because the standard Haynes Roadster set-up would have clashed with the 4×4 front differential.

In addition there was :

  • The chassis is 4 inches wider than standard at the centre, although it is approximately standard width at the front.
  • I am using 19″x 8.5 inch wheels all around on this Locost. If I simply bolted them to a standard car, it would look jacked up like a off road 4×4. I therefore had to move to mounts up the frame to lower the car back down.
  • I was never a fan of the Transit drag link top joints and that sliding joint arrangement

– basically the whole A-Arm arrangement had to go.

Whilst I was re-designing everything, I built in 25% anti-dive geometry. I also made these a-arms highly adjustable. Sure there is adjustment in the standard ones, but with these I can achieve precise adjustment of all suspension characteristics. Inspiration for the bottom A-Arm came from a visit to a local motor museum where they had a early 80’s formula 1 racing car.

I confess the brackets aren’t completely welded 360°, but with the engine in place it’s hard to get my head to a place where I can actually see what I’m welding. The brackets are definitely not going to move, so I’ll weld them completely when I strip everything down for powder coating. I’ll flip it over and do it properly. Mainly parts of the chassis are still like this; they are strong enough not to budge or flex; but await final TIG welding.

I must also confess that once you see a the front top mount welded into play on the car, it does look a little lets say  ‘huge’. At least no-body could say it’s flimsy and I never claimed I was making a super lightweight racer. It would be much smaller if I had used the standard Haynes Roadster chassis shape at the front. I didn’t because I wanted to use an original 60’s shape nosecone and it didn’t fit inside, the protruding tube looked rather ugly. I wanted something more purposeful that I could mount the headlamps onto – that’s if I don’t go ahead with a custom body (new one under development).

Haynes Roadster Front A Arms
Haynes Roadster Front A Arms

If I keep the standard bodywork, I’ll make some custom fibreglass bodywork to cover this. It’ll keep those IVA inspectors a little happier.

What is a little disappointing, is that the front urethane tube on the offside top arm somehow must have twisted during final welding. I’ll heat it up and see if I can bend it back into shape. If I can’t, then I’ll be making a new arm.

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