Spindle thread

[Morleydog]

So, hope you are all well.
Could anybody tell me the thread size of the swinging arm spindle on the C15.
I have measured the bolt at around 11mm (so 7/16)
I asumed UNF, but my thread book says 20 TPI and this appears to be 24.

[chaz]

if they are the same as the B40 with the grease nipples on the ends then Drags and Wassels sell as 26tpi so 7/16 BSC

[Morleydog]

Could be 26, just my rough counting. Thanks

[Bess]

Hi,
    This may help:

https://bsaunitsingles.com/item.wws?sku=40-4216

This is used after 1960, I think the bolt 40-4070 without the grease nipple tapping was used up to 1960.

Best wishes...

[chaz]

https://www.draganfly.co.uk/index.php/component/hikashop/product/7399-
used on B40's 1965 along with
https://www.draganfly.co.uk/index.php/component/hikashop/product/7398-

[Morleydog]

Thanks everyone. The plot thickens, but I have decided to acquire a tap and die set to free up the bolt into the spindle.