Chuck
A couple of questions first. What year is your Lambert Bicycle? What is the
size of the hex head of these bolt (if you even have a sample)? If it
doesn't fit your American or metric wrenches then it is a Whitworth Form
Thread. It sounds like this is a coarse thread which might make it BSW
(British Standard Whitworth). If it is a 3/8" bolt it will have 16 TPI just
like an American bolt however the angle of the threads will be 55 degrees
with rounded crests and roots (tops and bottoms) versus 60 degrees with flat
tops and bottoms of an American bolt, read NOT interchangeable.
To confuse the issue even more many British motorcycles used CEI (Cycle
Engineers Institue/British Standard Cycle) threads, but these were a fine
thread (all sizes I believe had 26 TPI but early cycle threads were 20 TPI)
and it sounds like your bolt has coarse threads.
The first place that I would call is British Toll & Fastener in Los Osos,
California. Phillip Brown is the owner and a wealth of knowledge all of the
British thread forms.
His number is (805) 528-0418. I know he has a web site but I don't have the
address.
I hope this helps.
Cheers
Curt Arndt
Carlsbad, CA
'55 BN1, '60 AN5
In a message dated 3/2/01 8:43:32 AM Pacific Standard Time,
chuckc@attglobal.net writes:
<< I'm appealing to the collective wisdom of the list to solve this
one. I need a bolt. Two would be nice. It's somewhere
between a 3/8 nc uUS thread and a M8 (8 mm diameter)
1.25 pitch metric. I believe it to be Whitworth, or something
similar. I'm restoring an old British Lambert racing bicycle
and these are (or would be) the crank bolts.
I would like to know a) what the correct size is likely to be, and
2) where I might find a pair.
Thanks in advance ... >>
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