I purchased a vintage crank a while back only to find out that it may have been more antique than merely vintage. It had the diamond (or some call bayonet) shaped crank arms, and I found that a modern RHS cone could not get past the left-handed LHS threads (also oversize). Headset washers (1") fit over the cranks. I have since acquired another oversize, by happenstance.
[Sorry, no pictures yet - they might not show the slight difference between 15/16" and 1" anyway].
What bicycle maker used oversize 1" diameter ID sprockets and cranks (vintage motobikes)?
So, the most standard OPC and sprocket is 15/16" and 24 threads per inch (at the sprocket side).
I have found an old skip-tooth chain ring that does fit the 1” crank, but it is a rusty Ivan Johnson like style snowflake decoration with a rectangular slot instead of a round drive pin hole.
[Sorry, no pictures yet - they might not show the slight difference between 15/16" and 1" anyway].
What bicycle maker used oversize 1" diameter ID sprockets and cranks (vintage motobikes)?
So, the most standard OPC and sprocket is 15/16" and 24 threads per inch (at the sprocket side).
I have found an old skip-tooth chain ring that does fit the 1” crank, but it is a rusty Ivan Johnson like style snowflake decoration with a rectangular slot instead of a round drive pin hole.
