DDK - Die Deutschen Klassiker

Grateful for some advice about how to determine and measure offsets. On my recently bought 911T I have (I believe) one Fuchs 6J x 15 with a shallow depth from the rim to thedeepest part of the front of the wheel, and three which I suspect are repro and are deeper, simply labelled 6 x 15 (no fox emblem). However my friend has two sets of wheels from 1970 and 1972 'S's which are genuine and have a very deep distance from rim to inner. This is hard to explain, but bewteen us we have three different depths of wheel. Now as far as I know, Brian Anderson claims that there is only one offset depth on the 6J x 15 used by Porsche on the early 911's. Any one shed any light, particularly on where the measurement of offset is taken?
Thanks, Paul A de V

What you probably have is one late 6" and 3 early "deep dish" 6" rims. The late rim has a 911 part number, the early has a 901 part number on the back of one of the petals.

I have both early and late for sale to complete your set

Having re-read Paul's post, I reckon they may be Maxwheel copies. The easiest way to tell is to prise off the cap amd look at the casting, it will have a sandcast finish. The genuine Fuchs was forged and has a smooth finish. The Maxheel has a heavy 6 x 15 in the casting

Max wheels also look like copies, the outter edges of the petals seem more square. Off set for all 6s were the same. Many people preffer the look of the deep early 6s, combined with the limited numbers made in comparison to the late flatter 6 they are more expensive. I also have sets of both if you need pics or info Paul.

Cheers

Alan

The off-set is the difference between the centreline of a wheel and the face that fits flush to your hubs .
If the centre line is outside the line of the hub face it is termed negative off-set ( common ) if the centre line is inside the line of the hub face this is positive off-set ( unusual )
To check your off-set :
A) Measure width of wheel rim to rim , and divide by two to get centreline.
B )Measure from the face that fits flush to the hubs to the inside edge of your wheel , (straight edge across rim helps ) .
B minus A will give you your off-set .

Confused ? ....You will be !

This may help to explain:

Andy,
Thanks for that comprehensive explanatory diagram - now I know exactly where I should have been measuring to get the quoted figures - but offset is not an easy thing to measure, given that it is to an imaginary point on the centreline. For the purposes of comparing Fuchs wheels, repro or original, would it not be preferable to measure to tangible places on the wheel, say from rim to deepest point of the outer surface.

Alan, I am still waiting for my repos to be measured so I can conform whether or not they are the same as yours. Were there more than one make of Fuchs repros available?
Regards,
Paul

Hi Paul

Yes more than one manufacturer alone has made up replica 6 inch wheels. Finding a part number is probably the easiest way for you to deterimine if the wheel are original or not. This is ok for 6 inch rims but I have seen 4.5 inch rims and 7R rims with no part numbers yet did have fox marks.

If I can find out the weight of the forged porsche rim you could then just weight them and compare.

The part number on an early 6 look like this.

I hope this helps. If you can send a pic Paul I may be able to tell you by looking at it ?

Alan

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There is a great thread on PPabout rim offsets and how to measure them

To measure the offset place as traight edge across the back of the rim, measure the distance to the mounting face, this is the "backspace", then subtract half the measurement between straight edges placed across the front and rear faces

Just out of interest -are there lots of manufacturers who make replicas and what is the cost relative to the originals?


F

I would guess that a set of copies might be worth £200 - £250. I have 4 Maxwheel 6" x 15 Fuchs copies, I will post a picture later today

cheers Nick.

F

Alan , Re your picture, is the fox sometimes in a triangle without any part number, and what would be the difference if there is no Porsche part number,
Paul

The little triangle (top left in this picture) is the Porsche logo

Hi Paul,

Are we still talking about 6 x15 rims. I have seen what you describe on 4.5 x 15 inch rims, 5.5 x 15 rims and also 7R rims with not on a 6 inch rim. Unless illegally done by someone I would think that the fox sign should make them original, but without seeing them it makes it very hard. Sometimes the part number is actually there but under the 30 years of brakes dust and grime.

Alan.UK