3 replies to this topic

[Teapot]

Pickup
1981

Just trying to get my head round a few suspension geometry details .... am I right in thinking
that wheels like Huey's Superlites, being offset inwards, are a Good Thing?

(Disregard the fact that they're 13" -- I'm going to have to work with that)

[mini13]

YES!

ok, looking from the front (or rear) of the car, draw an imaginary line through the top an bottom ball joints down to the floor, in an ideal world this will be near to the centre of the tyre.

however on mini's the tyre centre line generally ends up quite far outside of this point, and the furthur go go from this point the stronger the keick back you can get through the steering.

oh the distance between these points is known as the scrub radius.

as an idea of how big this can be, with 7x13's the point that the line through the ball joints meets the ground can be inside beyond the inside edge of the tyre. as nearly all 7x13's are offset -7(mm) (meaning they are further out from the car) if you put sports pack wheels on (offset+ 20ish) you have reduced the scrub radius by nearly an inch.

i belive most 10 wheels are offset +20 to +35, metro rims can be up to +45.

[Teapot]

Thanks! Just what I hoped. I've been swotting up on Calver again where he's explaining
kingpin inclination & offset and I wondered if I'd got the hang of it.




Actually the diagram is misleading because it's slightly skewed

Edited by Teapot, 23 November 2009 - 11:08 AM.

[mini13]

Yep, King pin off set and scrub radius are the same.