Speedo drive thread

[Clive Taylor]

Hi folks, does anyone know the thread form and size on the tin hub speedo drive. That's the thread that mounts the drive in the brake plate with a lock nut. It measures about 0.712 inch which doesn't seem to fit any standard thread I know, even pipe threads.
Please enlighten me.
Thanks
Clive Taylor.

[garybam4711]

Hi it’s .718 26tpi or 23/32 26 tpi both the same
gary

[Clive Taylor]

Thanks Gary, strange size. Cycle thread I suppose. Wonder why they chose such a non preferred size.
Thanks for the info.

[garybam4711]

Shame you are so fair away as I have a die and a home made tap I could of cleaned up for you
gary

[Clive Taylor]

No problem Gary, I'm so far away from most people. Thread in brake plate is fine and drive is recoverable. I know someone with full set of Cycle dies so should be ok. I wonder why such a strange nominal size was chosen. Thanks anyway.