superclarkey, munkul and ade b are talking facts
Honestly, peeps need to go grab a couple books, this is fairly simple stuff too grasp. This forum is making it complex. Google and youtube have some usefull info
BTW if you have low offset wheels or big spacers, you get increased tramlining, less stability during braking ect ect. Cars with diagonal split braking systems utilise negative scrub incase of brake failure and some cars like mk1 and mk2 fiestas have negative scrub and can brake in a straight line safely with a blown out front tyre.
zero offset wheels are really not optimum. maybe mitto means zero scrub, aka centre point steering
To most people this stuff isn't relevant... does my wheels turn.. yes, mint lets do a skid
Sorry, i was under the impression this was a drift forum... and no, thats not what i mean. I'll make some diagrams
Tomorrow, right now I feel like shit with some kind of flu.
You can have it if you like... It feels like my nose is about to cave in.
Have you got a version in Japanese Anime for mitto to watch, unless it has Japanese roots he will not except it to be fact :P haha
(only playing mitto)
Don't mistake contact patch and scrub radius; they're not the same thing. The rear wheels have a contact patch but no scrub radius.
Scrub Radius is established by SAI and Camber but what it does and how it behaves is also related to Castor, Ackermann and Wheel offset (either spacer'd or just a different wheel).
Scrub radius can be measured, though TBH I'm never really sure what the number tells us as there's never any OEM info to compaire against.
Wierdest thread ever.
Glad its resolved though as I was doubting myself bigtime then.
Last edited by Stavros; 27-06-2012 at 22:02.
Its also worth remembering that changing wheel and or tyre size will also alter the scrub radius
OK so to make the point...
Your examples are all "static" and do not take into account the dynamic factors involved.
So without moving the centerline of the wheel and only adjusting the postition of the wheel hub closer or futher away from the cars hub, you are adjusting the load axis point of the hub / wheel and also adjusting the amount of wieght involved.
by using a higher offset wheel you are moving the wieght, or "lever" further away from the axis point. Like trying to use a jack handle from the top or the bottom, the bottom is super difficult, but the top of the handle is easy. The same occours when you move the mass of the wheel further away from the hub / axis point.
Because the axis of load has been moved away from the hub, the effect on the suspension and the force put into the tyre changes, because the movements are dynamic. You've created a longer levering system and will cause geometry changes, the most obvious from this example being camber.
Camber change = scrub radius change.
Thats how I see it anyway.
edit - I'm assuming you can see the images...
Last edited by mitto; 28-06-2012 at 14:09.
physics care where the spokes are mounted! So what you are saying is that if you shift a point of leverage it has no effect in the slightest? Or that if you shift wieght around relative to an axis it does nothing?
For the principal of this explination the centreline is constant, however, the centerline and balance point of a wheel are different things.
This is my point about it being complicated... It's not a case of "fits the same, must be the same" - you are fucking with a huge number of dynamic factors.
Lol. I give up.
And RE the rest of your argument (spoke position change), the physical load placement on the wheel would be effected, but after a 10sec ponder I don't even think it would effect any other geometry changes.
That would make your complete argument invalid, not just its foundations.