Date:         Wed, 10 Feb 1999 11:05:51 -0000
Reply-To:     Malcolm White <Malcolm.White@SIEMENS.CO.UK>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Malcolm White <Malcolm.White@SIEMENS.CO.UK>
Subject:      Home made Syncro 16" trailing arms???
Content-Type: text/plain; charset="iso-8859-1"

I can't help with recommendations on fitting spacers behind the hubs but I
reckon that I've found some wheels that would allow the fitting of 16" tires
without fouling the trailing arms.  Euro Car Parts in the UK sell ERW alloy
wheels and they have a number of classy alloy wheels (Mercedes fitting) that
are 7.5x16 ET18 (unfortunately, they don't do a 15" rim in this offset!), so
the problem is rather whether you foul the wheel arch or not! They have a
wheel called the Alpina, which is a 10 spoke with centre cap (split pin
type), the multispoke, a 15 spoke alloy, and a twinspoke which is a 5 spoke
with each spoke being a pair of spokes (IYSWIM) . The benefit of a Mercedes
fitting is that the centre does not require machining whereas the Audi
fitting does.

As I understand it, the Audi wheels are typically ET45 and most Mercedes
wheels are ET35-45. Therefore, if you apply the following 3 tire sizes, 205,
225 and 235 here's the additional inner and outer tire widths for the
different offsets;

                        Additional Inner Dist (mm)      Additional Outer
Dist (mm)
ET30 (185, standard)            0                               0
ET45 (185)                      15                              -15 (less
track!)
ET45 (205)                      25                              -5 (less
track!)
ET45 (225)                      35                              5
ET45 (235)                      40                              10
ET35 (205)                      15                              5
ET35 (225)                      25                              15
ET35 (235)                      30                              20
ET18 (205)                      -2                              22
ET18 (225)                      8                               32
ET18 (235)                      13                              37

Following private discussions with Tim Smith, he is using 6 x 15 ET45 Audi
rims with 235/75x15 BFG MTs and these just about rub on the back trailing
arms and clear the front upper A-arm by about 3/8 inch. The main danger with
using the larger offsets is the overall reduced track, particularly with the
narrower tires (<225). On the other hand, using an ET18 rim might put undue
load on the wheel bearings and would probably require wheel arch work /
extensions (would look purposeful though :-))

I got fed up working these out so knocked up a simple Excel file that
calculates all the dimensions, including inner and outer rim and tire
widths, overall rolling diameter and percentage difference over stock by
inputting the tire and rim size. I'll gladly email it to anyone who is
interested.

Regards, Malcolm