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Old 5th July 2017, 15:39
Mike Mike is offline
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Originally Posted by Rickard View Post
Fig 1.
Fig 2.

Hi Peter - I adding this pictures, maybe it will explain the problem better... and No - spacers will just add more problem with this scrub radius.. I want it to be as the left picture (fig2) and now I have the middle scenario with Cortina hub and wrong ET at the rim. Green line is the middle of the tyre and the red line is the line in between centrum of upper and lower ball joint. The interesting point is where this lines crosses the level of the tyre, at the ground, see fig 1

So my solution will be like the right picture - find a rim with a ET that are greater than 50 mm to get the distance between red and green line so small as possible - SFRO can let my car pass if it is about 20-40 mm and the front geometri allows so big scrub radius without making the car instable when the suspension works up and down, because when you have too big scrub radius then the car will start turning by it self when you drive into a hole or over a bump - and that is something they(SFRO) wants to provide when you builds your own car. If it is not a good geometri I will need to go down to scrub radius at about 15-18 mm.

If you get it like the right picture the car could feel very dead in the steering - it is neutral and scrub radius is 0 and if you want a more active driving you need to have some scrub radius to tell you whats is happening with the car - so the best is the left picture.

So I am very interested to hear from other Marlin owners - how it looks like for your car...


Do these diagrams showing bump steer help?
Sorry about the size!

Out of interest I have calculated my Sierra hub has an SAIof 11 degrees.
I then calculated my scrub radius is 24mm with a -38mmET on a 16" wheel and 215/55/16 tyre using the dimensions shown on Super7thheaven

My Cabrio drives really well at speed - it does not move around - even at 90mph when it is getting very light due to the air getting under the wings!

I do have some self centering , but at full lock it is not too good.
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