bigger wheels/spacers affect handling?

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nomorebmws

bigger wheels/spacers affect handling?

Post by nomorebmws »

So from 16X8 wheels to a 17X9 wheels that need it a 1/2" spacer in the front. now car still shakes/bounces? steady around 75mph, struts inserts, shocks, mounts, links have been replaced, tires are a bit big for these 17" @ 235/45R17
wheels are BMW not aftermarket.
has anyone notice a difference on handling after going from a smaller size wheels to a bigger size? I also cannot longer burn rubber at take off.
like I use to do before. what could be the problem?
Jon Ackermann

Post by Jon Ackermann »

Are the middle and r/l tie rods new ?

Are the control arms/thrust arms new ?

If not, bigger tires/wheels will make a big difference and make the worn out ball joints show up more with the added width of the tires.

Thanks.

Jon
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Brucey
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Post by Brucey »

if you compare the centreline of the tyre now vs where it was before with stock wheels and tyres you may find that it is offset now. This loads up the suspension and makes for bad steering and extra wear.

Spacers if used need to be

1) hubcentric

2) of very good quality


if 1 from 2 above then shakes are very likely
if neither above shakes are guaranteed

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
nomorebmws

Post by nomorebmws »

so that's what it is, cheap spacers, not hubcentric, it only vibrates at high speeds, 75 mph or higher. I'm gonna go for the smaller tires 225/35R17 maybe that way I don't have to use spacers. instead of the 235/45R17 I have now.
Chris Wright

Post by Chris Wright »

What is the offset of the rims? Are they off of a 7 series?

Do they have the usual 72.56mm center bore for the hub or are they the larger bore from the e39?


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Here is a cut and paste of some general info:

The size of the original rims and tires that came from the factory:

..................................... Rim Width x Diameter - Offset or "ET" (mm) - Tire Size
Stock wheels ('76 to '81) ............ 6" or 6.5" x 14" - ET22 with a 195/70 -14" tire that has a diameter of 24.74"
Stock wheels ('82 on) ................ 6" or 6.5" x 14" - ET22 with a 205/70 -14" tire that has a diameter of 25.30"
TRX (165mm x 390mm) ............... 6.5" x 15-3/8" - ET22 with a 220/55-390 tire that has a diameter of 24.88"
TRX (195mm x 415mm) ............... 7.6" x 16-3/8" - ET19 with a 240/45-415 tire that has a diameter of 24.84"

The typical replacement rim is

7" or 7.5" x 16" - ET20 or less with a 225/50-16 tire that has a diameter of 24.85"
7.5" or 8" x 17" - ET20 or less with a 235/45-17 tire that has a diameter of 25.32"

The Tire diameters range from 24.8" to 25.4" .

The rears have plenty of space and can take an 8", 9" or even a 10" wide rim with the proper offset and tires of 255 or 265 unless you have the SLS accumulators, in which case the 255 and up can hit them in hard cornering. It is the front that is the most critical and an 8" wide rim is generally the largest without a spacer or a smaller ET.

The larger the rim and tire the more stress that is put on the front suspension and the more likely to inroduce a shimmy into the front unless the front suspension is tight.

All BMW's (except the e30) use a 5 x 120mm bolt pattern and are "hub centric", i.e. they are centered by a lip on the hub, not the bolts. They all have the same size hub hole (72.56mm) with the single exception of the larger hole in the e39 which will still fit fine, but they will need hub centering rings (not spacers), $15 from Discount tire. Most after-market rims have hub rings also. The 3-series rims generally won't fit because the offset is too high, running around ET40/48 and the 7-series with an ET of 23 will generally need a hub centric spacer of 5-10mm depending on the width of the rim. Sometimes a narrower tire (215/205) can be fitted to the 7-Series rim without a spacer and not rub also (but I think is depends on the rim width).
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Here is a good Rim/Wheel Size Calculator:
http://www.wheelsmaster.com/rt_specs.jsp

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Here is a site that lists all of the wheels that BMW made, with pictures and specs and the cars they came on:

http://felgenkatalog.auto-treff.com/
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