Does anyone know the thread form and size for the speedo gear mount inside the brake drum? It's a long shot... it seems to be either 26tpi or 1mm pitch. Since the chronometrics had metric threads I imagine either is possible. I can't tell the difference using my thread gauge. Then will it have 55 or 60 degree angle? It looks like I might have to make an adaptor to fit a 54mm gear onto a 52mm boss. No idea why...
As both Metric and BSC …
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Thanks Michael. I'll try 60…
Thanks Michael. I'll try 60. It's not heavily loaded.
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That would be a very useful…
That would be a very useful table to have if you own a Norton, covers the common threads but some are 'form' threads that use and different tpi, watch out for these. Don't assume the thread conforms to a table, Norton used many that didn't.
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Interesting...
... what sort of areas would these non conforming combinations be Ashley? just so I'm aware.
I like my prewar machines as they all seem to have a set of fasteners that conform albeit to various Whit, BSF, BCycl and Bbrass; the later machines always catch me out and I'm never sure what I have, especially when a PO has slipped a metric equivalent in.
Good info,
Thanks..
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As both Metric and BSC (cycle) threads have 60 degrees angle, I think 55 degrees is unlikely.