Low profile wider tires noisier?

"bimbim" > wrote in message
ps.com...
>
> Mike G wrote:
>> "bimbim" > wrote in message
>> oups.com...
>> >
>> > Mike G wrote:
>> >> "bimbim" > wrote in message
>> >> oups.com...
>> >> > Holy ****! I think I got X5 wheels!??
>> >> >
>> >> > To give you all a few more facts to base your responses from, the
>> >> > wheels and tires were off of my brother's 98 Z3 who went for 18"s.
>> >> >
>> >> > These Z3 wheels are staggered 17X8" and 17X81/2" with these tires:
>> >> > Front Continental ContiSportContact 225/45R17, Rear Toyo Proxes-T7-S
>> >> > 245/40ZR17.

>> > If I go to tirerack.com they recommend 17X8" +40 on front and 17X9" +45
>> > on rear with same tire sizes I have now.
>>
>> I think you've got that the wrong way. I'm sure the profile should be 45
>> on
>> the 8" rims, and 40 on the 9" rims.
>>
>> My rear wheels is +41, I can't
>> > remember the front.
>>
>> If you don't know you should certainly check. Incorrect offsets can
>> really
>> compromise the handling of a car. Especially with front wheels. It could
>> be
>> the cause of the change in the steering feel.
>> Mike.
>
> I have checked the front offset and it's +41 too. Thanks.

AFAIK, all E36's have a 35mm positive offset front and rear. On the Z3 the
offset is 41mm, so although the wheels from a Z3 will physically fit on an
E36, they are bound to affect the steering.
Ideally the wheel offset should be the same on front wheels as the offset of
the wheel mounting face on the hub, so the steering geometry stays the same.
Mike.

Mike G wrote:

>
> AFAIK, all E36's have a 35mm positive offset front and rear. On the Z3 the
> offset is 41mm, so although the wheels from a Z3 will physically fit on an
> E36, they are bound to affect the steering.
> Ideally the wheel offset should be the same on front wheels as the offset of
> the wheel mounting face on the hub, so the steering geometry stays the same.
> Mike.

I thought they were more like 44 or thereabouts depending on the width.

E28 Guy© wrote:
> Fred W wrote:
>
>>JRE wrote:
>>
>>>E28 Guy© wrote:
>>>
>>>
>>>>Why the hell would you have
>>>>two entirely different *brands* of tires on your car?
>>>
>>>Actually, I did that quite on purpose on a Civic as a cheap way to bring
>>>massive understeer under control...
>>>
>>
>>Really? So how would one induce oversteer on a front wheel drive car?
>>This one I want to see...
>
>
> He didn't say *overcome*. He said "bring ... under control". You
> could definitely influence the extent of the understeer tendency in a
> FWD car by doing this. You could conceivably achieve some slight
> oversteer. I know that a race-prepared GTi I drove some years ago
> exhibited slight oversteer - or at least a lot more than I got out of
> my 'street' Toyota FX-16.

Good point, he did say that. When I think of getting understeer "under
control" I think of getting the car to oversteer, but I suppose getting
it close to neutral would qualify.

>
> In fact, oversteer is rather easy to induce on a FWD with a good rear
> wheel handbrake. I used to be able to do 180° 'bootlegger turns' with
> mine. =8^D


Hah!! I knew someone would bring up the ole' handbrake move.

--
-Fred W

> wrote in message
ups.com...
>
> Mike G wrote:
>
>>
>> AFAIK, all E36's have a 35mm positive offset front and rear. On the Z3
>> the
>> offset is 41mm, so although the wheels from a Z3 will physically fit on
>> an
>> E36, they are bound to affect the steering.
>> Ideally the wheel offset should be the same on front wheels as the offset
>> of
>> the wheel mounting face on the hub, so the steering geometry stays the
>> same.
>> Mike.
>
> I thought they were more like 44 or thereabouts depending on the width.

AFAIK the offset of a wheel allows the centreline of the wheels to be in the
correct position relative to the offset of the hub wheel mounting face.
IOW, no matter how wide the rims are, providing the offset is the same as
that of the hubs, their c/line stays the same. With rear wheels it's not so
important, but a different offset on front wheels must affect the steering,
as in effect you are altering the steering geometry. Whether the alteration
is acceptable, is something else.
Mike.

Mike G wrote:

>
> AFAIK, all E36's have a 35mm positive offset front and rear. On the Z3
> the offset is 41mm, so although the wheels from a Z3 will physically fit
> on an E36, they are bound to affect the steering.
> Ideally the wheel offset should be the same on front wheels as the
> offset of the wheel mounting face on the hub, so the steering geometry
> stays the same.
> Mike.
>

I would think that the offset should increase with the wheel width...

--
-Fred W

"Fred W" > wrote in message
...
> Mike G wrote:
>
>>
>> AFAIK, all E36's have a 35mm positive offset front and rear. On the Z3
>> the offset is 41mm, so although the wheels from a Z3 will physically fit
>> on an E36, they are bound to affect the steering.
>> Ideally the wheel offset should be the same on front wheels as the offset
>> of the wheel mounting face on the hub, so the steering geometry stays the
>> same.
>> Mike.
>>
>
> I would think that the offset should increase with the wheel width.

The offset has nothing to do with wheel width.
The offset of a wheel is the dimension between the mounting face and the
c/line of the wheel rims.
Mike.

Mike G wrote:
>
> > wrote in message
> ups.com...
>
>>
>> Mike G wrote:
>>
>>>
>>> AFAIK, all E36's have a 35mm positive offset front and rear. On the
>>> Z3 the
>>> offset is 41mm, so although the wheels from a Z3 will physically fit
>>> on an
>>> E36, they are bound to affect the steering.
>>> Ideally the wheel offset should be the same on front wheels as the
>>> offset of
>>> the wheel mounting face on the hub, so the steering geometry stays
>>> the same.
>>> Mike.
>>
>>
>> I thought they were more like 44 or thereabouts depending on the width.
>
>
> AFAIK the offset of a wheel allows the centreline of the wheels to be in
> the correct position relative to the offset of the hub wheel mounting face.
> IOW, no matter how wide the rims are, providing the offset is the same
> as that of the hubs, their c/line stays the same. With rear wheels it's
> not so important, but a different offset on front wheels must affect the
> steering, as in effect you are altering the steering geometry. Whether
> the alteration is acceptable, is something else.
> Mike.

You are probably right as that makes a lot of sense.

--
-Fred W

Mike G wrote:

> >
> > I would think that the offset should increase with the wheel width.
>
> The offset has nothing to do with wheel width.
> The offset of a wheel is the dimension between the mounting face and the
> c/line of the wheel rims.
> Mike.

As the wheel gets wider one starts to run out of room one side or the
other so there is usually some adjustment to the offset.
For an E36 the following are listed as original fitment...
6X15 offset of 42
7X15 offset of 47
7X16 offset of 46
7.5x17 offset of 41

"bimbim" > wrote in message
oups.com...
> Holy ****! I think I got X5 wheels!??
>
> To give you all a few more facts to base your responses from, the
> wheels and tires were off of my brother's 98 Z3 who went for 18"s.
>

If you got them from a Z3, they are not X5 wheels.

The Z3 tires and rims should be interchangeable with the other 3 Series
cars. The stagger, in and of itself, is not necessarily a problem, and the
stagger numbers you cite are normal stagger for the 3 Series cars.

Jeff Strickland wrote:
> "bimbim" > wrote in message
> oups.com...
> > Holy ****! I think I got X5 wheels!??
> >
> > To give you all a few more facts to base your responses from, the
> > wheels and tires were off of my brother's 98 Z3 who went for 18"s.
> >
>
> If you got them from a Z3, they are not X5 wheels.
>
> The Z3 tires and rims should be interchangeable with the other 3 Series
> cars. The stagger, in and of itself, is not necessarily a problem, and the
> stagger numbers you cite are normal stagger for the 3 Series cars.


Thanks all to your wonderful insights, they are all valid. Yeah, I
think the new offset should be acceptable, also it should have a little
effect on steering.

I think I'm getting used to the noise. I seem to hear it more when my
windows are closed as there is no outside noise to mask it.

I also looked closely on the stretch of asphalt road I take, and it's
unbelievably wobbled. The lanes have raised bumps on the sides perhaps
either it was pushed up or the usual tire track deepened. These are at
minimum an inch high. I think the switch to wider tires has made these
bumps more apparent. I needed to be more alert on steering when
changing lanes.