The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Russ on 28.08. 2018 13:34
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Attached is a photo of the front forks which came with my project 51 - A10 Plunger.
They are not a set as the lugs to attached the centre mudguard bracket are different.
Can some-one please enlighten me as to what I have.
Thanks Russ
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Just back from the shed & I'm sure their the same as mine on the swing arm..
they suit the 1956-7 Ariel type brake ;D
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yep look like my '56 s/a too....
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G'day Russ.
Having a closer look the distance back to the shoulder in the right one looks deeper. I'll measure my spare tonight.
Cheers
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They do not look like a pair the mudguard stay brackets are different.
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G'day Russ.
Sorry for the delay, dug'em out with the plunger frame today. Jeezz I need to sort out that shed.
The 56-57 forks I have the smaller bore is 13/16", the 1" recess is only 9/32" deep. The other side is 1" bore.
So the one on the left may be a 56-57 but the right is different in that the recess doesn't look the same size as the bore of the left one and the recess is deeper.
So after all that I have no idea what the right one fits and most likely not a pair as Julian and yourself suspect.
Cheers
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Hello guys, thanks for your thoughts sorry for my delay in replying. Just got back to the forum. I now have a correct pair.
Cheers Russ
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Gidday all. Have just bought a complete front end that have the same type of fork legs as in the above photo. As with most people I think, it was a bit difficult to identify exactly what I had going by the photo's on the web site. So anyway, have a nice front end with what is apparently an Ariel hub set up. Problem is, I also bought a rather nice full width 8" front wheel. So I guess my million dollar question is.....can I change out the fork legs for ones that'll suit the wheel? According to Draganfly I need 67-5057 for the left, and 65-5420 for the right. Cheers
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Quick answer is yes. The fork bushes are the same across the range, so the correct slider to suit the wheel hub and mudguard mount can be sourced. Problem is that many sellers don't know what they have, and mis-describe.
Bit awkward to end up with Ariel sliders, they were only offered for a short time compared to the rest.
Julian S is the fella with the facts when it comes to the finer differences in sliders and their applications.
Swarfy
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Those part numbers are for the forks with 8 inch half width hubs with screw in spindle, the 8 inch full width hubs take a different part with clamp up spindle.
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Hi Julian,
So have had another look at the Draganfly parts list, which quite frankly is leaving me somewhat cross eyed and none the wiser...
So possible sliders include - 42-5051 and 42-5050...or...… 42-5078 and 42-5076. Are you able to advise? Cheers, Tony
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Right, so I may have answered my own question. Just had a look at the Draganfly web site and searched 42-5076 and 5078. Going by the photo's, they should be the right ones for the full width 8" hub. Bit of a pity they say they can no longer supply these.... *sad2* Neither does Mikes Classics by the look of it..... *conf*, and nothing on fleabay. So I suppose next option is to look for an Arial front wheel to fit the forks.
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Tony. The real problem with these parts lists is that the sliders don't have any identifying marks related to the part number. The only thing constant is the bore of the tube. So while Drags print chapter and verse, identifying the actual part you have or want is difficult.
The mudguard mounts differ over time, flat brazed on mounts to start with, varying heights up the slider depending on model, then later two stud fixing with Y bracket to the front guard.
Lower stays can be front and back, or back only, so the lower stay lug design changes.
Brake backplates differ. Some have no anchor to the slider, using a torque arm to the mudguard mount eg half width 8." Some types use a cast in slot which engages on a tab on the leg. Yet others use more complex arrangement.
Add to that the design and requirements of the front spindle, then add at least two styles of lower clamp and you can see the possible chance of error. Finally whatever you get may have its own set of faults..dents, pulled or poor threads to name a few.
So, a bit of a minefield for sliders. Correctly identifying the yokes is another test. Some look physically identical but have different part numbers, but the same forging number. Usually down to one forging being ground or drilled and tapped to suit different model variants.
One thing for sure, it ain't gonna be easy.
Have a look at A65 sliders. Spindle and brake arrangement are the important things to go for. Ariel wheels were superseded fairly quickly, not really a good brake by experience.
Cheers
Swarfy.
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Dont forget all the A7 A10 parts books are available on this forum;
https://www.a7a10.net/forum/index.php?topic=12471.0
42 5076 and 42 5078 are from the 1958/59 twins and the B31/33 and take the full width iron hubs.
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Julian. Thanks for posting.
Tony, you can see the sliders have the spindle clamp, fit the hub, but not the later front mudguard as they do not have the later two stud fixing for the Y support under the mudguard bridge. Choice depends on the year you want and whatever parts you already have sourced.
Swarfy.
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These are the final version of the forks for the full width hub A7 and A10 Swarfy refers to.
Used from 1960 until 1965 including the A50 A65 full width hub models.
The fork bottoms used on the 1968 only A65 lightning and Spitfire Mark 4 are similar in appearance to the 1958/59 parts but need different internals to take the damper rod. They also have stronger clamps and mudguard stay brackets.
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Given BSA's full width hub brake would be in breach of today's trade description act, I'd go for fitting the Ariel wheel.
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RD Agree with that. The Ariel has its charm, but for my money a well set up half width hub type is the best of the standard options. Simple, lots of adjustment, and ability to reverse the lever as debated in earlier posts.
Swarfy
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Well I've managed to sort it out. The guy I bought the forks and front wheel from has in fact got the correct wheel in stock, so we'll do a swap. It's not as bright and sparkly as the one I got, but at least now I know what I'm dealing with. Will have to replace the rim and spokes, but again, but that's all good simply due to knowing what I have/need. In conclusion, todays lesson is - all that glitters is not gold. ;)