I got a whole new car for < US$ 5 000

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Sep 26, 2005 | 11:40 PM

#41

BMW#7

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From: USA

Quote:

Originally Posted by das' date='Sep 27 2005, 03:15 AM

[quote name='BMW#5' date='Sep 26 2005, 03:02 PM']Ok so Style 135
18 x 8: 8" wide, ET 20mm (0.79" offset) = 4" (wheel centerline) + 0.79" offset = 4.79" distance from hub,

and

172 wheel, 19 x 9.5: 9.5" wide, ET 32mm (1.26" offset) = 4.75" (wheel centerline) + 1.26" offset = 6.01" distance from hub

Which gives:
6.01" - 4.79" = 1.22" or 30mm more offset from hub on 172 rear wheels vs 135 rear wheels.

I could beleive a 15mm difference, but 30mm is just not possible. Could we be neglecting a factor of 2 somewhere in the calculation?

[snapback]175308[/snapback]

Ok, I think I finally figured out what I am doing wrong. Width does come into play, but the offset isn't "added" to the inside "half" of the wheel from its centerline; it's subtracted from the outside half!

Let's take a look at this diagram again:

I have been adding A + C to get B, the rim's "backspace", and those calculations are indeed correct. But what we are looking for is the distance from the wheel's bolt face to out outer edge of the rim, in other words, not A + C, but A - C (or, 2A -

. So let's try this again:

Style 135
18 x 8: 8" wide, ET 20mm (0.79" offset) = 4" (wheel centerline) - 0.79" offset = 3.21" distance from hub

Style 172
19 x 9.5: 9.5" wide, ET 32mm (1.26" offset) = 4.75" (wheel centerline) - 1.26" offset = 3.49" distance from hub

Which gives:
3.49" - 3.21" = 0.28", or 7mm more offset from hub on 172 rear wheels vs 135 rear wheels.

Now let's do the fronts:

Style 135
18 x 8: 8" wide, ET 20mm (0.79" offset) = 4" (wheel centerline) - 0.79" offset = 3.21" distance from hub

Style 172
19 x 8.5": 8.5" wide, ET 18mm (0.71" offset) = 4.25" (wheel centerline) - 0.71" offset = 3.54" distance from hub

Which gives:
3.54" - 3.21" = 0.33", or 8.4mm more offset from hub on 172 front wheels vs 135 front wheels.

Does that look better?

------

Soooo...width still comes into play, but I was just figuring the wrong dimension!

For what it's worth, this also means that the Style 172 wheel is inset an additional 4mm than the Style 166 wheel on the rear, and 6mm on the front. And that answers my worries about the Style 166 sticking out too much on the xi; the Style 172 seems like it will work just fine:

Style 123 (for reference)

4" - 0.787" offset = 3.213"

Style 172

Front: 4.25" - 0.709" offset = 3.541" - 3.213" = 0.328" (+8.33mm)
Rear: 4.75" - 1.260" offset = 3.490" - 3.213" = 0.277" (+7.04mm)

Style 166

Front: 4.25" - 0.472" offset = 3.778" - 3.213" = 0.565" (+14.35mm)
Rear: 4.75" - 1.102" offset = 3.648" - 3.213" = 0.435" (+11.05mm)

Based on that information, I feel comfortable ordering the Style 172 for my own car.

[snapback]175450[/snapback]

[/quote]

That's spot on Dave.

Sorry but I only saw your diagram above this morning. Was reading on my phone yesterday, and kept image download off

Now anyone interested in trading some 10mm spacers for my 15mm spacers??

I think that the 172's + 15mm are just slightly too much. The set up on my 135's + 15mm was perfect, so I really need to add an 8mm spacer, but I don't think that size is available.

Sep 26, 2005 | 11:42 PM

#42

BMW#7

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From: USA

Quote:

Originally Posted by shiny' date='Sep 27 2005, 09:33 AM

Man, I love those wheels. They are now on my wishlist, they look absolutely brilliant, better even than the M5 wheels.

However, Mrs Shiny hates you, as she's not getting a new kitchen now?

[snapback]175604[/snapback]

Show Mrs Shiny what beautiful wheels will be taking her to the restaurant, and all will be forgiven.

Sep 27, 2005 | 10:28 AM

#43

BMW#7

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From: USA

Quote:

Originally Posted by stu' date='Sep 26 2005, 06:33 PM

Thanks for the update on the Michelins. My 124's (current Dunlop DSST run flats) need new tyres, COSTCO only stock Michelin and I was unsure about buying them.
The rears are over 260GBP each, it's a big expense. I want to make the right choice.

[snapback]175195[/snapback]

Stu,

I say get the PS2's.
They are MUCH more comfortable than the Dunlops.

Check out www.tirerack.com, which is where I got mine. They have some useful comparison tools and reviews & tests.
.

Sep 28, 2005 | 12:49 PM

#44

Grafiker

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Joined: Sep 2005

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My Ride: E60 2005 535d Sport, Carbon Black, 19" M-light Double Spoke 172 8J Alloys, Media Package, Bi-Xenons, Heated seats, Black Dakota leather, Sun protection glass.

I have the same wheels on my 535d Sport which incidentally, is the same colour as yours, picked it up last week. Your pics look great. Enjoy.

regards
Grafiker

Sep 28, 2005 | 01:01 PM

#45

Serge007

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Joined: Sep 2004

Posts: 251

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From: Austin, Texas

My Ride: 2004 525i, Jet Black, Black Dakota Leather, Poplar Wood, Steptronic Transmission, Premium Package, Xenon Lights.

I like the car color selection

Oct 2, 2006 | 06:39 PM

#46

ferri

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Joined: Aug 2006

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From: Taipei, Taiwan

My Ride: 2006 523i M Sport Package white 2002 996 C2 silver 1997 993 C2s red

Quote:

Originally Posted by BMW#5' post='175023' date='Sep 26 2005, 01:48 AM

Well I am finally free from my Runflats

I got my Style M 172 BMW wheels mounted on Friday with Michelin Pilot Sport 2 tyres, and the difference is amazing

It is like driving a brand new and different car all together

Despite being an even lower profile than I had before with the M 135 Rims, the ride is much smoother. I no longer feel all those tiny road imperfections and bumps to the same degree. Obviously you still feel them to a degree, but at least it is now like a damped or gentle feeling, rather than a harsh jolt.

Here are some pics (please excuse the poor lighting):

Note: I still have the same 15mm H&R Spacers on the rear.

Hello

You car sure looks awesome!!!
I am about to get rid of the 135 on my 523iM and replace it with 172...may I ask what is the use of the 15mm H&R Spacers?
Thank you for the feedback