The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Lightningpower on 29.07. 2010 06:30
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I found a pair of yokes that are supposed to be A10/A7, but they are narrower than other a10 ones I have seen. The casting number on the underside of the top yoke is: 65-5365. I'm looking for a set of 1953 plunger yokes. Will these work? What are they from?
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I cannot see a 65-5365 but 65- 5355 is BSA B models. If they are more narrow then this will be what they are for. They are not suitable for an A 10 because they are narrower the front wheel hub and mudguard will not fit.
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360272216645 item listed on Ebay as
A pair of original BSA steering yokes.Top yoke part number 65-5365 used but in good condition Top yoke measurement at widest point approx 8 1/4 inches,measurement centre to centre of fork leg holes approx 7 inches.Bottom yoke measurement at widest point approx 8 1/2 inches,measurement centre to centre of fork leg holes approx 7 inches.Suitable for BSA Single and Twin Plunger (Spring) models etc.
Seller could be wrong though, item ended BTW
I'm sure someone here will have a definitive answer
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The "3" in the number is a difficult one to read up close, it looks at once like a 3 a 5 and an 8! So, if you say it's a five, it probably is. The photo definately makes it appear more like a 5. A B model hey? I wondered if it was for a C model. B model would be good. There are more of them around here.
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What should the casting number be on a plunger A7? I found a whole slug of yokes but none were anywhere close to the number in the parts book. I assumed they were A65.
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According to Draganfly parts book for 1953 both A and B models use part No 65-5430.
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That's helpful. Could they be C15 or C11? If BSA used the same yokes for A and B plungers, then can I use the same wheel as a Goldstar? Or the same forks?
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Casting no.s & part nos are usually 1 digit different.
If you search the Draganfly site, 65-5364 takes you here:
"65-5364
Top yoke (66-5088U)
THIS PART SUPERSEDES TO 66-5088 PLEASE SEARCH AGAIN USING THIS NUMBER
GBP 0.00"
Which leads to A/B 49-52 & M 49-57.
Of course they could be wrong!
Nothing close in a 49 A7 parts book!
In general if the centres are correct (ie 7") you can use but you will have to pay attention to steering stop layout (there are at least 3 varieties) vs the stops on your headstock.
Also steering damper bottom bracket may have issues.
There are also issues with shrouds as the length between top & pinch bolt cut outs are not all the same.
Safe to say I have some experience in these departments *ex*
Cheers
Rusty
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BTW I am chasing fork yokes for 1948 longstroke A7 that are 225mm across the top. The others for BSA A10 etc measure 215mm. Anyone have a set I would be grateful. cheers Terry
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Hey there. Goldy,
What are the casting numbers?
The yokes pictured above measure 215mm accross. Are they then suitable for use on a 53 A7?
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Hi all,
I've resurrected this thread as it is the one and only reference I can find anywhere to the top yoke number 65-5365. I picked up a random BSA front end for a reasonable price with the usual side note - "suit rebuild", and of course no other hint as to what model it might be off. I've stripped the whole lot down and started removing the old paint and rust etc. So as you can imagine, I've come across this part number, and out of curiosity decided to have a look at both the Draganfly and BSA Parts Lists to see just what I had. Nothing...nada...nought and nout. So, I wonder if one of you fine gentlemen would care to take a calliper out and measure a few dimensions and report back? What I have is - overall width of the top yoke is a smidge over 8 and three quarter inches wide. Centre to centre of tube holes looks to be around 6 and half inches wide.
The fork tubes are about 32mm in diameter. If these dimensions match what you'd find on a std rigid/plunger, then I will carry on doing them up. If not, then I guess they'll be going on eBay.
Incidentally, I'm using a 7" half width front wheel which is in good condition. The bushes are also in excellent condition with zero side play. So it would be a pity not to use them, but if they're wrong, then they're wrong and I'll just have to go back to the drawing board. Regards, Tony
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I think the photographed yokes are for the 1946-1946 B31 33 33 and 34 models.
Not the same as A10 because the column in the bottom yoke is 1 inch diameter, A10 slightly larger. shaft centres are 6 1/2 inches, A10 is 6 3/4 inches and the steering bearings used different cups and cones to take 3/6 balls on the B ad 1/4 on the A10.
Cups smaller than A10 (same as C10/11) and dont fit the A10 frame.
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Sound like C10/11 ones. My c11 seem identical to the A/B type except that they are narrower (6" headlight). I'll go to the shed later and see if the numbers are visible if not I'll have a measure.
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Thanks guys. Have done a proper measure up and got the following dimensions. Shaft on bottom yoke is 1.126 inches. Centre to center of the top yoke is 6.78 inches. So based on your comments it sounds like I do in fact have the A10 set up? Cheers Tony
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Had a measure up A10 and M21 top yoke 8 1/4" overall, 7" between centres. C11 top yoke 7 3/4" overall and 6 1/4" between centres. Couldn't get to numbers. I know the C11 stem nut looks the same as A10 but is in fact 1/8" smaller. I wouldn't have thought it was worth making the two types when they are so close in dimensions.