Hollow Spoke Metal Valve Assembly?
 

Hi all,

I'm in the process of getting my 993's solid spokes replaced with hollow spokes off a 996TT. I ordered a new set of valve stems since I had the wheels refinished and want to make sure the tire place installs the valve stems correctly.

I searched through previous threads and found some posts but not definitive pictures on how these should be assembled. In particular, is the washer (which has a "dish" type of design) and the stem nut can each be assembled in one of two orientations. The washer is the hardest to describe, so I've taken two pictures of the possible orientations.

One datapoint from a thread four years ago: "On mine, the concave shallow part of the washer faces the wheel, and the convex dome part faces out. This seems intuitive, as you would want as much force as possible spread over a larger area of the washer. I would include a pic, but you can barely tell the difference looking at it on the mounted stem." This seems to indicate that it's the first pic below, but can someone verify?

Three questions, then:
1) Is the order of assembly (o-ring, washer, stem nut) shown in the pictue correct?
2) Which picture shows the correct washer orientation?
3) Should the nut portion of the stem nut be closer to the wheel or the Shrader valve?

Thanks for your help!

first picture all as is 100% correct, regards

Thanks, geolab! Hollow spokes went on the car yesterday with the valve stems as noted, and it all went without a hitch. Much appreciated!

Thanks for the post. Sent my wheels out for re-finish last week and was able to send them these pictures when they called with questions. Disaster avoided :thumbup:

So the washer is shown correct in the first picture but is backwards in the second? How tight on the nut? Thanks

And the interesting thing I read about the hollow spokes, if correct.
If a crack develops in the spokes, an air loss will happen to clue you in of the crack.
Supposedly a main part of the design design?

That's a very interesting point. I was reminded by a friend recently about the 917 (?) strategy of pressurizing the chassis tubes to do just that - if a loss of pressure occurred it was a clue there was a crack in the chassis tubes somewhere. Brilliant.