Hello,
I'm making haynes roadster front lower wishbones, with a narrower track. I believe these wishbone tubes are normally made from 25mm o/d tube with 2mm wall thickness in CDS tube. But I have seen plenty of people using ERW tubing to do the same job on various builds over the years

As I have a load of 25mm, 2mm ERW should I just use that or buy some CDS tube

Cheers
David

You need to consider the design, if you make the extended bones but leave the shock landing point the same distance from the chassis then you will be loading the arms as increasing leverage which may lead to buckling.

If you point the end of the shock at the lower ball joint as below this takes a considerable load off the bones but may need to consider the open length of the shock, ERW will be fine.



Either way expect to need stronger springs.

For mine I used landrover panard rod tube, very tough with much cheapness.

[Edited on 1/6/12 by mark chandler]

Thanks Mark,
I've narrowed the track so the wishbones are shorter not longer, the front suspension is basically a narrowed Haynes Roadster setup. The lower wishbone coilover mount is now closer to the chassis (because of the shorter wishbones) and therefore the coilover is much more upright which I think is good for the coilovers as in the standard Haynes design they are very steeply angled.

But the lower coilover mount is in the same position as standard ie in distance from the maxi ball joint, I can't move this outwards because of the design of the lower wishbone plates, they have a lightening hole just where it would be ideal to move the wishbone mount to

Some people may wonder why I have spent my time modifying a Haynes setup into a locost escort width suspension setup, why not use the Ron Champion locost setup as is. After looking round the various forums, the locost was slated for bump steer but although plenty of people had there opinions on it being wrong, not a single person could actually say why it was wrong and perhaps offer a solution.

I have measured the haynes and I was really struggling to see a millimetre over 125mm of suspension travel, I also measured the cutdown side and was struggling to tell any difference. I also for comparision measured a classic mini suspension over 75mm travel and it was nearly 5mm!

Cheers
David

When I built mine I had to take 3" out of the rack housing and 4" out of the rack itself to eradicate bump steer.
It occurs because the rack inner ball joints are not in line with the centreline of the chassis bone brackets, by moving the rack up higher you can lessen the impact, the front of the car is simply not as wide as an escort, mines early width BTW.