Author Topic: 1940 forks  (Read 703 times)

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Online enfield49

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1940 forks
« on: November 27, 2021, 05:34:50 PM »
I really do not know enough to know if I have enough parts to assemble a set of forks for my civilian C11.I definitely need a handlebar clamp, were these fitted to bikes other than C's ? The wheel spindle hole seems too large did the 7" brake have a bigger wheel spindle? Can anyone recommend a book which could help ? Graham

Online Owen

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Re: 1940 forks
« Reply #1 on: November 27, 2021, 06:16:09 PM »
The reason the wheel spindle hole is larger is the wheel spindle nuts have a shoulder to locate the wheel. They had the 5 1/2" brake hub with a slot for the Speedo drive.
1940 C12 (350cc)
1945 C11
1953 C10 & C11

Online enfield49

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Re: 1940 forks
« Reply #2 on: November 27, 2021, 08:27:28 PM »
One problem solved thanks. Graham

Online timsdad

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Re: 1940 forks
« Reply #3 on: November 28, 2021, 08:26:04 AM »
The 1940 C forks are the same as fitted to the pre-1938 B range - B20, B21, B23 etc. I have no idea why BSA used different girders on the first C 10s in 1938/39. I suppose they designed new forks to go with the new frame and then discovered the earlier B forks were better.

Ray
Just a motorcyclist.

Online Owen

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Re: 1940 forks
« Reply #4 on: November 28, 2021, 08:30:54 AM »
The brake plate strap mount is in a different position on the earlier versions to the 39/40 C model forks
1940 C12 (350cc)
1945 C11
1953 C10 & C11

Online timsdad

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Re: 1940 forks
« Reply #5 on: November 28, 2021, 08:39:16 AM »
Yes, I know, Owen, but that's a very minor thing. Don't forget, I had both models too and actually fitted a pair of 1938 B20 forks into a 1940 C. It's because the front brake is different due to the later type of speedo drive on the C model.

Ray
Just a motorcyclist.

Online MilitaryRon

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Re: 1940 forks
« Reply #6 on: November 28, 2021, 09:12:46 AM »
Actually Ray, the forks fitted to the 1939 model C10 were the same forks as fitted to the 1934-36 B1's. Leon has confirmed via the parts lists. I've no idea why they went back to those earlier forks? Maybe they found an old stock pile? Ron

Online Owen

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Re: 1940 forks
« Reply #7 on: November 28, 2021, 10:41:29 AM »
I wonder why did they reduced the size of the friction discs for the 38 model and then go back to the earlier larger discs?
1940 C12 (350cc)
1945 C11
1953 C10 & C11

Online camman3

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Re: 1940 forks
« Reply #8 on: November 28, 2021, 11:14:42 AM »
As Ron says, probably old stock pile,they wasted nothing in those days.
Graham
1957 C12
In sunny (sometimes) Christchurch, Dorset, UK

Online timsdad

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Re: 1940 forks
« Reply #9 on: November 28, 2021, 02:53:35 PM »
BSA moved in mysterious ways!

Ray
Just a motorcyclist.

Online enfield49

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Re: 1940 forks
« Reply #10 on: November 29, 2021, 10:55:24 AM »
What size should the friction discs be in 1940 ? Graham

Online MilitaryRon

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Re: 1940 forks
« Reply #11 on: November 29, 2021, 11:23:17 AM »
These are the 1940 forks Graham. I make the discs about 2 1/4"- 2 3/8". Ron

Online Owen

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Re: 1940 forks
« Reply #12 on: November 29, 2021, 03:28:28 PM »
We are just in the process of adding the friction discs to the site shop. There are two type/sizes, 15-5050 small for the 1938 models and 15-5051 large for the 1939-46 girders. We will also be adding the (29-5225 & 65-5166) 1939-49 girder fork link bolt nut retaining ring set for BSA C10, C11 & C12 (350sv) shaft clips which are cheaper than on Ebay.
1940 C12 (350cc)
1945 C11
1953 C10 & C11

Online enfield49

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Re: 1940 forks
« Reply #13 on: November 29, 2021, 04:51:44 PM »
The diameter of the friction discs matches my forks . It appears I have bought the correct forks. by some fluke . Graham

Online Owen

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Re: 1940 forks
« Reply #14 on: November 29, 2021, 04:57:47 PM »
1 9/16" for the 1938
2 1/2" for the later discs
1940 C12 (350cc)
1945 C11
1953 C10 & C11