knucklehead inner tube stem sizes

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1950Panhead
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knucklehead inner tube stem sizes

#1

Post by 1950Panhead »

Knucklehead 18" wheels from the 30's have a stem hole of .525"
Palmer says 36,37,39 used Schrader valve stems while 38 used rubber stem.
Today I can get a metal TR6 stem with nuts, .314" diameter (small for .525" hole)
Or TR13 rubber stem (no nuts) .460" stem.
Cannot find any tubes with .500" metal stems like original.
Guessing owners are using rubber stems.

Any wisdom ?
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Re: knucklehead inner tube stem sizes

#2

Post by RUBONE »

Many guys are using the metal stem with the repop Schrader stems screwed on for the vintage look. I haven't checked to see the OD of the stem on the repop stems. There are some shown in the new AMCA mag in the Strange Bird ad.
1950Panhead
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Re: knucklehead inner tube stem sizes

#3

Post by 1950Panhead »

Thanks Robbie,
These nickel-plated vintage Schrader style valve caps are screwed directly onto the metal valve stems of modern inner tubes with small outer diameter, ...
https://www.wwag.com/cgi-bin/WebObjects ... =!WW000239
1950Panhead
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Re: knucklehead inner tube stem sizes

#4

Post by 1950Panhead »

The factory used 5/32 x 5/8 flat stock for the thin braces.
Hard to find unusual size, I was fortunate to find some.
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1950Panhead
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Re: knucklehead inner tube stem sizes

#5

Post by 1950Panhead »

The factory used 13/64 rivets for the thin braces.
I was fortunate to find some 13/64 rivets on ebay made by Whitaker mfg in the 40's or 50's.
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Re: knucklehead inner tube stem sizes

#6

Post by 1950Panhead »

I made the flip fender braces, fastened with 13/64 rivets.
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