1961 B40 screw threads

[Cargers]

Hello,
I have just bought my first old british bike. I have had dozens of jap machines and also hinkley triumphs, all metric threads. What screw threads are used on my B40. I presume they will be BSF.
Thanks Ian.

[JulianS]

You will need BS spanners.

Many of the threads are British Standard Cycle, 26tpi for smaller bolts, 20tpi for 7/16 and larger. Threads into aluminium alloy cases usually BSW. Small threads in Lucas electrical items usually BA.

[Cargers]

Thank you Julian,
I will get some spanners and look out for some taps and dies.
Ian

[Pete C]

Get a thread gauge. An invaluable tool for checking what you are dealing with, particularly on an old bike where someone may have introduced wierd (metric) repairs.

[Spaceman]

I have 3 x sets of spanners on the wall in my workshop for use on the bikes I work on: BS, Unified (AF) and metric and 5 x sets of taps and dies: BA, BS, BSC, Unified (UNF and UNC) and metric. With so many types of thread around, I definitely need a thread gauge and, for convenience, I've got the thread data for all the thread types typed out and also hanging on the wall. 

That said, for working on a B40, BSC is normally all you need but you never know what someone might have used as a replacement since new. I, for one, am guilty of mixing BSF and BSC.

[Cargers]

I had an ojd socket set box full of old taps and dies that my father had from his motorcycling days.
unfortunately at the time I was riding Hinkley Triumphs and Yamaha RD 2 strokes so did not need the taps. I sold them to a friend who had Velocettes a long while ago. I will have to keep an eye out for taps, dies and spanners.
Cheers Ian.

[Mike40M]

Though my unit singles are a bit more modern, BSA was fond of Phillips #3 screws. The usual PH2 screwdriver slips.