Dumb tire/wheel question

[Jon Tara <jtara@xxxxxxxxxxxxxx>]

OK, here are a bunch of stupid wheel and tire questions, JUST IN CASE
there haven't been any lately! Hopefully, this will foster much debate and
polarized opinion - something I'd much rather hear here over whweels and
tires than to hear out of the windbags in Washington. :)

Which weighs more? Tire or wheel?

OK, I realize this is relative - WHICH tire? WHICH wheel? But, er, OK, how
about in general?

Generally, when doing a "+n" upgrade, and assuming that the wheel and tire
widths are not changing (a bad assumption) will this generally increase or
decrease the overall weight of the tire/wheel combination?

I guess what it boils  down to is which is heavier per cubic inch - rubber
or aluminum alloy?

On a related topic, does anyone have a good comprehensive source of wheel
weight information? Has somebody published a handy-dandy chart? It's quite
frustrting trying to get what sould be common information. Generally,
manufacturers and distributers don't publish weights (except in a few
cases where they make it a marketing point), and I have gotten
inconsistent answers from distributers (for example, anywhere from 17 to
20 pounds for a 17x8 BBS RK) and sometimes-ambiguous answers from
manufacturers.

Can somebody comment on the practical conseqnences of wheel-weight
fanatacism? I know that less unsprung weight is a good thing.
But how much "less" does it take to be noticible? I was talking to one
wheel vendor, who has a variety of wheels ranging from 17 to 20 pounds for
the size that I want. They stated that I "wouldn't notice the difference"
between the 17 and 20 pound wheels. (I liked the appearance of the heavier
wheel better.)

I know that 16-17 pounds is about the best that one can expect at a
reasonable cost for 17x8 wheels. (right?) Does anyone know what the weight
of the "factory" alloy wheels is? (I have the 15" 20-spoke for the 95
E36).

I've narrowed my choices to just a few (widely disparate) wheels: 

BBS RK - seems the practical, low-cost choice. Light-weight and
inexpensive. (Discount Tire mis-quoted them at $300 each, and I can
probably hold them to that. If not, they are around $350). They have an
asthetic disadvantage in that they are a very "open" design, and, well,
I've got ugly rusted brake rotor centers and calipers...

Breyton - Inspiration or Softline. Look real pretty in pictures, but
haven't seen them in person. Also inexpensive. 24 pounds, though. Will I
notice the difference between these and the RKs?  They also have the "open
design" rust problem. (I'm told "barbeque black" spray pain is the cure,
but I'm lazy...)

Kinesis - Totally overpriced, impractical 3-piece wheels, ranging from
17-20 pounds.  Have seen in person, since I work 1/2 mile from their
Carlsbad, Ca. headquarters. But, man, are these some sexy-looking wheels,
(check em' out in Roundel) and they'll anodize them any fool color I
want. :)

HRE - ditto. Haven't driven to Vista yet, about a 10-mile drive, but will.  
Have seen on a car (an M5, an indication of how silly it is to put
these on a 325...) at my mechanic.

OTOH, both Kinesis and HRE are cheaper than Schnitzers, anyway... (but
what isn't?)

Finally, comes the preputual question of size. A few months ago when I was
subscribed to the old  list, there seemed to be a lot of concern about bent
rims with 17" wheels, and it seemed a lot of people were opting for 16"
on E36s. The Kinesis folk were urging me toward 18", though. It's been 
suggested that bent rims are either an M3 factory-wheel problem, or an 
east coast, running-into-the-curb-on-the-ice problem. Would 3-piece wheels 
have less or more tendency toward bent rims? (Of course, with the 3-piece
wheels, I do have the option of replacing just the rim, at apx. the cost
of a 1-piece wheel...)

I do realize that the wheel size will affect ride comfort, but I don't
think that will be a problem. I opted for a Bilstein Sport/Eibach
spring/Eibach roll bar combo that some people have commented that they
find too stiff for the street, but I judge it to be a "luxury ride" on my
daily commute up I-5 and back. I honestly can't notice the difference,
except for the improved handling, and, yes, I can certainly feel the speed
bumps in the parking lot a work now. (Which I now do slolums around, and
SWEAR the reason I do that is because of the jolt I would get if I drove
over them. :) )

Thanks.

Jon Tara
BMWCCA #149631
1995 325is - shark/bilstein/eibach/eibach/wheels?

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