[Healeys] Speedo Drive Thread Size?

[Curtis Arndt]

Correction...

*Cycle engineers Institute (CEI)* - Older cycle thread superseded by BSC.
The angle of the threads is 60°. Not used on Austin Healeys.

On Mon, Aug 9, 2021 at 9:35 AM Curtis Arndt <cnaarndt at gmail.com> wrote:

> Listers,
>
> The most common BSC tread used on AHs was the steering wheel shaft thread
> and nut.
>
> Also BSC is the early version of, and was superseded by CEI - Cycle
> Engineers Institute.
>
> Both BSC and CEI are NOT Whitworth thread forms since they have a 60
> degree thread pitch versus the 55 degree pitch of a Whitworth thread form.
> The confusion arises in that fact that the hex heads on either BSC or CEI (
> I can't recall off the top of my head) can be BS/W requiring the
> appropriate spanner.
>
> See the attached pdf draft of my article on the subject. Any suggestions
> for this article would be greatly appreciated.
>
> Cheers,
>
> Curt Arndt
>
> On Sun, Aug 8, 2021 at 9:27 AM Harold Manifold via Healeys <
> healeys at autox.team.net> wrote:
>
>> Just when I thought I had a handle Whitworth, BSPP, BSPT, SAE, UNF, etc.
>> along comes BSC (British Standard Cycle). The threads on the transmission
>> speedo drive and the angle drive are not the best and could use a
>> refreshed. The pitch is 26 TPI and the diameter is ¾” as best I can
>> measure. After searching Google the closest match I could find is 3/4" X 26
>> TPI BSC.
>>
>>
>>
>> I have never heard of British Standard Cycle before. Can anyone confirm
>> if this is the tread size?
>>
>>
>>
>> Harold
>>
>
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