I picked up a mismatched set of plastic Peter Lynn buggy wheels a while back. I'm now trying to get the final Nanco Bigfoot lite on. The first two seated ok. The third tire would not hold air. At first it was because of how the tire was shipped (smashed down) and the two beads of the tires were not concentric. When I would get one side lined up the other would have a 3/8" air gap on the other bead. I eventually used a hair drier to get the tire into shape enough that both beads should seat. Still no pressure build up. I then remembered that one of the holes for the valve stem on one wheel was square where the others were round. Air is leaking around the valve stem at the square hole.

Why are square valve holes made and are special valve stems or adaptors made to fit them?

Maybe D shaped is a better description. It's leaking at the square corners.

It just sucks that I have had the tire on and off 5+ times before I remembered that one wheel was different.

Older model wheel? I'd like to see a pic of the valve stem hole.

I only took a picture from inside the rim.



I had a metal/rubber sealing washers that were larger diameter. I fillet cut the rubber off and put them on both sides of the seals already on the valve stem. It finally took air and appears to be holding.

Almost looks like that particular wheel was set up for use with a tube. All mine have a flat area to facilitate the valve stem.

That's crazy. I have various vintages of PL wheels - never seen that. Agree w' RTZ, could it be an enviably precise DIY mod to facilitate tube usage?