Where in the sva manual does it show the position of the front arches over the wheel / tyres from the top view. i have set the camber on our book chassis inwards by about 4 deg with the tops inwards to assist with self centering for the sva test. Now I have adjusted the arches so that a vertical line can go from the outside of the arch straight to the floor without touching the wheel or the tyre. troubles is when viewed from above I can now see the wall on the inside edge of the tyre sticking out from the the arch.
The only way to stop this is to reduce the camber and reset the arch again, but then it will not self cnetre as well ? Without the chance to drive it much it is a bit of a worry as to how to set it.

Not sure about the manual, but I don't think you need to worry too much about it. As long as you can't see the tread from above I think you'll be ok.

Cheers

Mark

This is straight from the testers mouth when we took a friends car for SVA.
The SVA tester talked me through the test.
The front arches or cycle wings must cover the rim, so it must cover the rim side to side but the tyre sidewall can bulge out beyond this, if the tread of the tyre comes outside the width it could fail the radius test.

Viewed from the front and the rear you can see the tread and is not tested.
From above a line is drawn straight up from the rim, front and back, the arch should cover these points, you may see some tread from above, this is not tested.

If you can see some tread then use some Car Builder Solution trim on the edge of the arch for SVA.
I also have a set of old spare arches, they look sh1t but easily cover my .

Thanks guys I have also been told it is the castor that may need sorting as this is what affects the self steer. Should be okay as far as the remarks above about covering the tread. Will probably go as we are on Fridayand then at least i will have a fail sheet to work from at worse.