Well that what had me baffled as I could have sworn he was going to go 19 rear 20 front but have discovered he laced up a 19 for the front thanks for the input mate.
French metric = 60 deg. and BA = 47-1/2 deg., so it seems these threads were made by a machinist who couldn't make up his mind and decided to split the difference: [60 + 47.5]/2 = 53-3/4 deg.one thread angle was 53 degrees, the other 55 1/2 degrees
I remember having to use one of those terrible 20 in.front tyres on the front of my twin in the early 70's while waiting for a decent one to arrive from Conways.I think it was an Olympic "Universal" It lasted an incredibly long time without showing any noticeable wear. I reckon they used the same compound to make their battery cases!Those last may not have worked as I would have liked so I downsized them to suit.
The barefoot young mans name is Danny he seems pretty chuffed to be sitting on the bike
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