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RIP 9/10/2017
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I'm buying an Alfa from a friend and it has tubed tires with aluminum wheels. I want to convert them to tubeless so I can use modern tires. I found some valve stems at Jeggs that has rubber seals with nuts on the inside, will this work?
 

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MJ, not sure which model of wheel.. or Alfa, probably doesn't matter... but there might be a good reason for the tubes... seeping wheels, older mag's are notorious for losing air.
Or the currrent tires have the same problem... A good tire store can probably check the wheels/tires for leaks and recommend from there..
 

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A tube tire has a different bead design from a tubeless tire. Likewise, a tube style rim, generally, is a different design.
Racing rims, traditionally, are fitted with all metal valve stems, sealed through the rim, for use with tubeless racing tires. They look like those pictured below. As mentioned above, OLD racing tires (Goodyear Bluestreak Sports Car Specials) lost air easily, even through the sidewall!:eek:
Wire wheels, used on Ferrari's have the same problem with spoke ends poking through the inside of the rim. The best way to attempt to seal all 72 of those is with rim-rubbers that are like a giant rubber band over the inside of the rim. THEN you used a tube.
Real magnesium wheels might, or might not leak through the rim itself. If the rim was leaky, you could have a crack. Even without cracks, painting the inside of real magnesium wheels was intensive on sealing the pores of the soft magnesium.
I run real magnesium (not light alloy) wheels on both my Ausca spider, (Minilites) and Ferrari's on the street and track. I use tubes in tubeless tires. Good tubes of the correct size, dusted with powdered rubber talc in tubeless tires, will still generate greater than normal heat, but will not leak anymore than tube type tires that normally loose pressure over time.
The heat issue is addressed with a tire pyrometer, just as it was in racing for years. Tire pressure is adjusted by heat across the tread. If the temperature is uniform on the outside and inside edges, and the center, after high speed use, it's about right. You do NOT seal the bead on tubeless tires, used with tubes, on tube type vintage rims.
From my experience.
 

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