I don't think they are. Can't see why they would be.

 

As I stated in #20, the only thing that changed when I changed wheels was the off-set from 48 to 40. I'm starting to believe this upset the alignment, probably toe in. Heading to a good shop tomorrow to find out. Any alignment specialists out there that can help on this?

 

No, with only changing the track width of the contact patch, you're only moving in one-dimension: outwards.
That shouldn't affect toe at all since you're not changing the plan-view angle from centerline of the vehicle.

Something else is going on that you haven't stumbled upon to yet... keep digging.

- Erik

 

without changing wheel width, you change what's called the scrub radius, and this will couple to steering feel and how much a change at one wheel will pull the steering and make the car darty. how much, I have no clue...

Anyway, work with a good suspension alignment shop and they'll be able to help you via alignment to get the handling you want.

FWIW, one of the reasons I really liked the Goodyear F1 GS3Ds was because of their tread pattern, they had some of the least tramlining I've ever experienced in a street tire.

And like Ryan said, the stock front control arm bushings suck, and the toe changes that they allow really degrade good handling. In all my time around Minis, I've only found two people who like them!

Matt

 

ALIGNMENT IT WAS!! Camber and toe-in was off on the left side and the heavier (6.5lb) OEM wheels were masking the problem. Balance was off, too. High speed straight line stability is now rock solid and the steering seems better, too. I be happy camper!

 

Motor On!

 

Duh..... Gumballs will have better GRIP, so they will follow the road surface, overpowering the almost total lack of front caster.
Want it to track straight? Buy garbage $25 tires with no grip.

As you have now learned, suspension engineering is a tad complicated. Might start reading books from Fred Punn or Carol Smith and learn a bit about the subject before you second guess the manufacturer. We may disagree with BMW's choices, but they are not stupid. Understand the choice first.

Might consider the ALTA bushing as it increases caster. No experience with it, but that is a claim. Increased castor provides better directional stability. BUT, it causes it to be harder to turn. And, it increases dynamic load transfer by lifting the front at turn in, increasing grip. It also changes the contact patch. See? Complicated.

 

Just to throw in to this way old thread, I'm paired on 17x7 Konig Feathers and Nitto Neo Gens. I swapped wheel and tire together, from my stock JCW R105's and Dunlop DSST 18" wheels. I do not feel a straight line instability, but when having steering inputs at highway speeds. The tail just feels like its fishtailing when jerking the wheel back and forth. Since then (10k miles ago), I have changed the struts to bilsteins, tried rear control arms for alignment (as im lowered), upgraded to a 19mm rsb, all to no avil. I played with tire pressure, and had alignments to stock specs, and even with the added front - camber. I felt maybe it was the new tire with taller tread and a a taller sidewall than my runflats, but its been 10k miles, and still the same feeling. Also, swapping to my winter set 16x7 wheels with 52mm offset (stock i believe), the problem is gone and the car feels tighter and I actually believe may handle better than my summers (lol).

It seems there is a trend with these konigs (with 40mm offset, as mine is), playing a factor on people's handling changes, regardless of tire choices. I know there are many other factors, but i figured i'd just add mine to the list for others searching.

Granted, if I'm on a onramp holding the wheel at an angle turning at a quick rate of speed, it holds well and doesn't roll, but if I let the wheel up a bit to sweep around a pothole while on the turn and turn back in, the car just feels like its about going to fish tail, but won't. Its just a very wavy feeling in the rear of the car. Again, this feeling is gone with my winter set, and the upgraded suspension did make the problem a little less apparent, but its simply masking it imo.