Author Topic: A10swing arm identification  (Read 1444 times)

Offline Plammimam

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Re: A10swing arm identification
« Reply #30 on: 26.10. 2018 19:08 »
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Offline Plammimam

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Re: A10swing arm identification
« Reply #31 on: 26.10. 2018 19:09 »
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Offline Plammimam

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Re: A10swing arm identification
« Reply #32 on: 26.10. 2018 19:37 »
One more dimension. When I fit the back plate in the hub with out the spacer and measure the stub axle, then refit the spacer between the hub and back plate. It lifts the back plate 0.059, which seems a reasonabl clearance

Offline duTch

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Re: A10swing arm identification
« Reply #33 on: 26.10. 2018 20:02 »

 Dunno 'bout the measurements, but for what it's worth that looks to be a Plunger type hub- S/A hubs don't have the R/H screw in bearing retainer....probably doesn't matter much though, I had what I think is a S/A hub/wheel in my Plunger and it 'worked'.....
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
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Offline Swarfcut

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Re: A10swing arm identification
« Reply #34 on: 26.10. 2018 21:03 »
 Looks like I was wrong. Brake drum is not a plunger type, it  has  the small centre hole and has finned drum, so are we looking at Gold Star/A65 Type?  As duTch says, likely to be a plunger wheel with two screw in bearing locking rings. Best option is custom made spacers and bushes to get it to work. Non standard engineering is fine if you do it, but sorting someone else's dream is a  nightmare.

  Swarfy.

Online BSA_54A10

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Re: A10swing arm identification
« Reply #35 on: 26.10. 2018 21:22 »
Wow nothing like home work guys, no pain no gain as they say here are the answers to the various questions. I will post the pictures with a couple of replies in a moment

Stub axle length, this is an approximation with out removing 3 1/4, diameter 7/8
Left swing arm slot 0.681
Sprocket teeth 46
Back plate hole 0.878
Bearing in hub OD 2 inch ID 7/8
Total hub width from outside edge of spline to outer edge of right side hub 4 1/8
Stepped spacer hub bearings sit on is 3.450 length

You will find things a lot easier if you keep to fraction of an inch and forget decimal measurements.
0.681 ~ 11/16" ( 0.6875" )
0.878 ~ 7/8" ( 0.875 ")
BSA used fractions and all parts are measured in fractions.
Now I am no metrologist but when it comes to these type of measurements it is micrometers in multiple places then averaging because we are talking about parts that are 50 years old and subjected to all sorts of bodgery.
Get some fuse wire or hair wire and measure the axle slots diagonally .
Good chance is you will find the two sides are not parallel.
Next of course doubt every part. No reason to suspect any part on the bike is what was there when it left the factory.
In the USA where they were toys there is a good chance the owners made the effort to get the right parts for their bike.
Down here or in the UK where the bike was daily transport then whatever wheel the owner could get from a wrecker ( because BSA riders were too cheap to buy new parts ) that would go in the hole & work or be made to work was better than the No 52 bus + 3 minute walk to the No 106 and the chance of making the boss angry by being 3 minutes late..

Then you get collision damage where the swing arm is bent back to put the wheel into alignment. I had a bike done & it was fantastic   , never tracked that good before, but when it came time to do the swing arm bearings the shaft would not come out. Carefull measurements confirmed that the pivot was in fact bent & it has to be cut like devon to get it out.
Finally to help you & us identify your wheel & swing arm & wheel, lay the entire axle out parts book style.
Usually if done like that you can compare it to the diagrams in the parts book.

Bike Beesa
Trevor

Offline morris

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Re: A10swing arm identification
« Reply #36 on: 26.10. 2018 21:22 »
Right. Here's some more plunger data;
Shaft diameter 7/8", length 10 1/4"
Wheel bearings RLS7
Bearing distance inside hub from outer to outer edge 3 3/8"
Drum bearing RLS8
Stub axle length 3 9/32"
Outer distance piece 1 9/16
Frame lug 15/16"
'58 BSA A 10 SA
'52 BSA A 10 Plunger
'55 MORRIS ISIS
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Offline duTch

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Re: A10swing arm identification
« Reply #37 on: 26.10. 2018 22:16 »

 May be irrelevant, but what year frame is it ?
 
 
Quote
....Finally to help you & us identify your wheel & swing arm & wheel, lay the entire axle out parts book style....

 After you've done that, I think you need to start by setting the sprocket  in alignment with the drive sprocket....you may find you need a spacer between the swingarm and brake plate, then go from there  ( I don't think chainwheel is A65- looks same, but fairly sure they all -after '65?- had bolt-on band )     

Quote
..You will find things a lot easier if you keep to fraction of an inch and forget decimal measurements......BSA used fractions and all parts are measured in fractions........

 I hear you Trev, but my digital caliper is in decimals, as was the vernier one before it went bush, even a micrometer is in decimals- a ruler in fractions is just a stick with scratches on it, good enough for ball-park guesswork *smile* I'm happy with metric also, but missed out on the cubit system- maybe my sisters did it  *conf2*
 
 I'm about to head out for the day and running late.....

Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline Plammimam

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Re: A10swing arm identification
« Reply #38 on: 26.10. 2018 22:37 »
Frame is 1961
We seem to have very similar dimensions for the axle and bearing bits. How about a question on the swing arm lug to lug dimension. I have seen drawings on the site giving
7 1/32 an 7 15/32. My one measures 7inches so could be the 7 1/32. If it was 7 15/32 it would probable all fit with standard parts. Is there a confirmed lug to lug dimension?
Have to say machining up good spacers is the best option as long as this lot is put together correctly. I think I will pull the whole thing apart and check the assembly. When sure it is good manufacture an appropriate spacer.
Thanks all
Phil

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Re: A10swing arm identification
« Reply #39 on: 27.10. 2018 17:49 »
plam I will measure part number 17 and also if I can find it the one for an A 65. also number 17 is a different part number in a plunger hub, it looks like you have the same set up as mine apart from the bigger slot in the swing arm?? as the other slot looks same as mine where the stub axel sits --- swarfy the spindle goes through the hub spindle sleeve which carries the bearings part number 30 which is also different in a plungy--- I will report back tomorrow  edit my swing arm is 7 inches but I could measure it better when I take the brake drum out

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Re: A10swing arm identification
« Reply #40 on: 27.10. 2018 18:26 »
there is some stuff on this forum from2010 about swing arms and but I don't know how to put it here, but I have noticed an A65 swing arm fits but is longer , and the spindle for a quick detachable rear wheel has what looks like a bigger diameter that fits in the frame where your swing arm has the larger slot is it possible it is an A65 arm *dunno*

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Re: A10swing arm identification
« Reply #41 on: 27.10. 2018 19:12 »
there is some stuff on this forum from2010 about swing arms and but I don't know how to put it here, but I have noticed an A65 swing arm fits but is longer , and the spindle for a quick detachable rear wheel has what looks like a bigger diameter that fits in the frame where your swing arm has the larger slot is it possible it is an A65 arm *dunno*
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Offline duTch

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Re: A10swing arm identification
« Reply #42 on: 27.10. 2018 22:34 »

 It occurred to me that if it is A65 S/A and or hub, then there should've a speedo drive in there somewhere, but the '65 list doesn't show that...but it does show a chainwheel like yours with 42 teeth for a couple of models, and detachable one for a couple others

'70 List shows the speedo drive...
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline duTch

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Re: A10swing arm identification
« Reply #43 on: 27.10. 2018 22:38 »

 I think  Hub with speedo drive has a external thread on the RHS...

 More hub pics which should be from  '70 list......
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline Plammimam

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Re: A10swing arm identification
« Reply #44 on: 27.10. 2018 23:38 »
Spacer 67-6028 and sleeve 67-6027 appear common on all the crinkle hubs. Looking at the BSA owners club library parts books you can run down all the bike types to get a feel for the set up. I think it appears a bit easier to look at specific bikes as opposed to some of the net information that covers a couple of models in one list. This set up has a tendency to look like a Goldstar rear wheel which appeared on the earlier 50’s models and then came back in the 60’s. This might be part of the idea from who ever built this up originally as the bike is like a Spitfire scrambler or Catalina