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Front suspension brackets positionning on a Locost
voucht - 2/1/24 at 05:47 PM

Hello Everyone and happy new year!

For the Locost, on Ron Champion’s book, there are all dimensions for positioning the front suspension brackets vertically. But I can’t find anywhere how to place them longitudinally (view from the side of the chassis), especially the top ones according to the lower ones, which will set-up caster.

Am I missing something? Should I position them so the top drag link and the lower ball joint axis are aligned vertically? Is there just no caster on this car?

Thank you.

Slimy38 - 2/1/24 at 08:45 PM

Caster is dealt with by the unequal arms on the top wishbone. You can add or subtract additional caster by moving the brackets but priority should be good positioning for strength. The top rear and bottom front brackets appear to be central on the RHS, with the other pair controlled by wishbone width.

jps - 3/1/24 at 07:57 PM

Are you building another one??!!

voucht - 5/1/24 at 09:35 AM

quote:
Originally posted by Slimy38
Caster is dealt with by the unequal arms on the top wishbone. You can add or subtract additional caster by moving the brackets but priority should be good positioning for strength. The top rear and bottom front brackets appear to be central on the RHS, with the other pair controlled by wishbone width.


Thank you for your answer.
By positioning the top rear and bottom front brackets as you say, which makes sense btw, thanks, I get a 5.6° caster angle. Seems about right, no?

voucht - 5/1/24 at 09:42 AM

quote:
Originally posted by jps
Are you building another one??!!


Hi John,

After years and years trying to get my Swedish-road-legal Haynes Roadster, French-road-legal, without any success, I gave up and sold it last month. The buyer will use it on track days, so at least it will have a second life. But it broke my heart, really.

So for now, I'm "building" a new one, yes, but just virtually on Solidworks And for a change I try the Ron Champion Locost.

But who knows, it might become real one day!

Slimy38 - 5/1/24 at 03:40 PM

quote:
Originally posted by voucht

Thank you for your answer.
By positioning the top rear and bottom front brackets as you say, which makes sense btw, thanks, I get a 5.6° caster angle. Seems about right, no?


Yep that's pretty much spot on, page 118 of the book says 5.3° +/- 0.3°.

voucht - 5/1/24 at 10:04 PM

quote:
Originally posted by Slimy38
quote:
Originally posted by voucht

Thank you for your answer.
By positioning the top rear and bottom front brackets as you say, which makes sense btw, thanks, I get a 5.6° caster angle. Seems about right, no?


Yep that's pretty much spot on, page 118 of the book says 5.3° +/- 0.3°.


Perfect! Thank you very much for the help

Myke 2463 - 9/1/24 at 04:45 PM

I built my locost which is a bit bigger than the std size with 6 deg caster after seeing many had centring problems, and have centring with no problems. The SVA tester was very impressed as many just scrape through. Build another one, you know you want to.