Does anyone know why one spoke is plain and the others are ribbed?
sewer drain.jpg

I got a new (to me ) set of sewer drains with excellent rubber today.
I began cleaning the 25 years of brake dust off and I noticed the missing ribs...

 

Cut to the scene where 500 owners are sticking their fingers in the slots of their wheels..........

 

Classic!

 

Heading out to the garage...

 

Wasn't ribbed for "extra pleasure" ???

 

Is valve stem located there?

 

Less material, to counter the valve stem imbalance? So they'll take the least weight possible to balance up?

 

Sewer drains???

They are referred to as 'manhole covers'.

 

So, I wasn't kidding. I ran out to my garage to look at the spare wheel I have (NOS that I picked up from a Porsche dealer cheap), expecting to see ribs...but it looks quite different. So, I pulled one of OE wheels off of my 84 Euro, and it looks like the one in the OP, with ribs (and yes, the flat spoke is right next to the valve stem.

The first 4 pictures show my NOS wheel, which has no ribs, and indentations indicating where more material would be removed to make a Club Sport wheel. The last 4 photos show the OE wheels from my 84, with ribs and no indentations.

I suspect that the "ribbed" design is older, and the one with the indentations demarking where the CS cutouts would be is newer, and supercedes the old style, likely so a single forging could be used for both manholes and Club Sports (with some additional milling)....

Interesting.

 

Brian,
If your theory is correct, then when they milled the wheel to make it a CS wheel all the markings would be on the discarded piece. Is that the case, that the CS wheels do not have any numbers stamped on them.

 

Hey!
You guys are really awesome.
I am working on a thread that will require even more tedium.

Mat I especially like the valve stem counter balance.

 

For comparison and comment and generally just fun.

[ATTACH]Man hole cover.jpg[/ATTACH]

 

More likely the tooling was modified to be able to run either wheel with minor setup changes.

 

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