Tandem Bottom Brackets T&C and earlier

[PCHiggin]

Hi,Are the threads BSC 1-3/8" X 26 TPI or English? ( I think thats the term) 1.370" X 24 TPI Thanks. I searched and found nothing.

 

[TR6SC]

Not exactly sure of your question. BSC (British Standard Cycle) is a different name for CEI (Cycle Engineers Inst.)
They are not the Whitworth threads, but they are British. W. is a coarse thread with 55 degree angles, whilst the B.S. Is the fine thread with the same 55 degree profile. CEI used 60 degrees like the Americans. Most, but not all CEI pitches were 26 tpi. The 1-3/8 shows up in the charts as 26. There is also reference to a 1.375-24. This might be an American pitch. If you haven't already got one, it might be time to get a thread pitch gauge. Am I addressing the question?

 

[PCHiggin]

I know they are not Whitworth,my question is, Is it a British Standard Cycle thread 1-3/8” X 26 TPI? Or, is it 1.370” X 24 TPI? Do you know the answer?.... I have plenty of Pitch Gauges, I’m trying to help somebody on the other side of the country, OK? Please don’t respond unless you know the answer. Thank you

 

[fattyre]

I doubt Schwinn used a bottom bracket made for Raleigh's. Either I just answered you question or added fuel to the fire....


https://www.sheldonbrown.com/bbsize.html

 

[PCHiggin]

Thanks I've seen that too but it doesnt answer anything. My thread starter asks about a specific bike. They used cottered cranks on these bikes. Its either BSC or English. I dont know which standard was used by Raleigh,dont care. Maybe someone will chime in yet

 

[PCHiggin]

Found the answer,Thanks metacortex.