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Re: rear stand

Bryon Currington
Just received a rear stand for the 1941 WM20 from India. Looks like it will fit ok. Not sure on the threads yet but that can be sorted.
The 3/8 hole on the left side for the holding bolt looks ok. The hole on the right side just above the ex pipe as had the metal broken away at the bottom of the hole making it now a slot or as it always bean a slot! It would be good to know before trying to attach it Bryon
Right the first time.
It started life as a nice round hole so some time with the Oxy torch look to be in your future.

email (option): bsansw1@tpg.com.au

Re: rear stand

The holes can wear badly and if you where thinking of welding in new bosses? This picture that Henk sent me might be useful. Ron
BSA_frame

email (option): ronpier@talk21.com

Re: rear stand

Are we talking about the frame or the stand?...

The stand bolts have a 5/16" Cycle thread, not 3/8"...

The shank of the bolts are 7/16", so that should be the size of the hole in the frame. One side of the stand leg is tapped to accept the threaded part of the bolt and the other takes the shank...

I've seen Indian stands before that have the wrong thread and hole size for the shank of the bolt...I think they might have copied a pre war stand or one from another model...That should be born in mind as if you have one like that you will need to modify the frame and make non standard bolts (and locking nuts)....

Also take care when welding the stand at the lugged end...If the material has broken away that may well indicate that they have used cast iron for the lugs...Entirely the wrong material for the application ...

I still have some UK made replicas (from a batch I commissioned) if you get stuck...Ian

email (option): ian@wright52.plus.com

Re: rear stand

Good point about the hole sizes Ian. I have some spare stand bolts (Drags) but didn't bother to dig them out to measure. But when he said "The bottom of the hole above the exhaust" had broken out, I just assumed it was the frame? Ron
c572af28a204e65cd9ccf746f390e046

email (option): ronpier@talk21.com

Re: rear stand

Great Photos Ron explains it all. I have not reached the stage on how to post photos yet but working on it. I am in Alberta so hard to find a bike to copy from. Yes the hole in the frame has broken away I did guess at a 3/8 size they will be as Ian stated no doubt. I could not find an email address for Enfield County where the stand came from to get the thread size I think it could be metric. I will have to get the step bolts made locally I think that's what they are called. Thanks every one Bryon

Re: rear stand

Drags have the bolt/washer/nut
https://www.draganfly.co.uk/index.php/bsa/bsa/a710--b3133--c101112--m202133/category/949-engine-plates-and-tie-studs

Ron

email (option): ronpier@talk21.com

Re: rear stand

Byron, here is the matching RH photo of that NOS frame.



Pay attention to the flat 'stop' area for the stand below the pivot hole - that wears away and is probably not 100%.
Compare this NOS one with one in grey primer above and you can see how it is starting to round at the bottom.

Re: rear stand

unable to order bolt kit from stock the Indian stands have 3/8 fine threads and a 1/2 hole opposite so will have to adapt Bryon

Re: rear stand

Bryon, based on the fact that your stand is wrongly made and might, as Ian said, be made from the wrong material which is liable to snap, also that you have to remove the rear wheel to remove and replace! I would ditch it and buy one of Ian's. "The cost is forgotten, long after the quality is felt" Ron

email (option): ronpier@talk21.com

Re: rear stand

What is the preferred method of repairing the stand holes in the frame. To weld them up and re drill or cut out the worn boss and weld in new ones?
Mine are pretty flogged out, especially the right side.

email (option): meck04@bigpond.com

Re: rear stand

I have just gone through this myself or rather my son as he being a mechanic and dab hand with a mig welder. The bottom of the hole on the right side was broken away but the mig welder made it look easy building a bridge and using a die grinder carbide bit to clean it up.
The stand it self was very poor the welding on it was pitiful I could live with that on an army bike it doesn't need to look pretty but the threads on the stand wrong size and not in line. The stand was taken away to put it in a press to bend one leg to match the other. The
eyes on the stand spring were to small to go over the shaft of the stand so I broke the eye open with a punch and welded a piece into it with no guarantee on the results. I have had decent parts from India but the M20 stand from there makes them look very bad. Merry Christmas to all

Re: rear stand

Stand legs are different one is straight the other is kinked, I thought of buying a Injun made stand but made my own instead, quite easy in fact..

Re: rear stand

Mark Farnay
What is the preferred method of repairing the stand holes in the frame. To weld them up and re drill or cut out the worn boss and weld in new ones?
Mine are pretty flogged out, especially the right side.
I like to drill them out, then run an end mill through them to get a better size ( yes I know a reamer would be better but they are forgings and rip the blades ) the make up a bush out of slightly softer material, like phos bronze.
As it has to be turned up to size I make about 4" of bush then part them off to width so I will have some spares to replace them latter on ( which of course can never find when needed ).

email (option): bsansw1@tpg.com.au

Re: rear stand

Dave T
Stand legs are different one is straight the other is kinked, I thought of buying a Injun made stand but made my own instead, quite easy in fact..
Yep the legs are just bent tube , not all that hard to make.
If you have a welding shop that can do furnace braizing then all the better.
I am about to weld some new feet to my stand.
I am looking at using the feet off some old swing arm stands to get a nice curve to make putting the bike on the stand that little bit easier.

email (option): bsansw1@tpg.com.au

Re: rear stand

Ron,

I will need to sort out a frame and back stand for a friend soon in the new year. His stand is at the wrong angle now and well under the bike, i have not had a good look at it yet but it will be a combination of pivot wear and the frame stand stops. What i need to know is are the main frame rear fork castings and the stand top pivot castings steel, or as someone has suggested they could malleable iron
castings. Any idea of the material before i start would be a help.

Tim W

email (option): t.j.walker@btinternet.com

Re: rear stand

Tim to my knowledge the original parts are all forged or cast steel and easily weldable. This can be the problem with Indian made parts which might well be sand cast iron and liable to snap under shock loads......I'm no metallurgist though! Ron

email (option): ronpier@talk21.com

Re: rear stand

I haven't been able to turn up any original BSA documentary evidence to determine whether frame lugs etc. were forged or cast, or manufactured from steel or malleable cast iron...

From a cost point of view castings would have been vastly cheaper than forgings...Additionally, the forging process is not well suited to producing the thin wall sections of many of the lugs...However, BSA had the facilities and sometimes didn't make the logical choice...But they also had an extensive capacity to produce 'standard' and 'special' castings via their many subsidiary companies....

The industry standard seems to have been based around heat treated iron castings and assuming that were the case, heating beyond about 850C would not be desirable...So welding and/or brazing temperatures should be considered and rapid quenching avoided.. Brazing is carried out below 850C, I don't know about the various welding techniques....I have to say I'm not an expert in this area..

Opinions vary regarding what materials were used and it is difficult to know who is right, so if anyone can come up with proof (rather than hearsay) I'd be interested to see it to answer this question...Ian

email (option): ian@wright52.plus.com

Re: rear stand

Thanks Ron and Ian for your info,

I know i will end up having to weld the rear frame casting's / forgings i am quite capable of welding or brazing the damaged parts but its better to know what material you are welding first.
My first thoughts were that they would be malleable iron castings as i am sure that larger castings like the headstock would me malleable iron. But this back frame casting what ever material it is takes a lot of stress and would have been better made from steel. This frame i am going to work on has never been repaired before so deserves a proper repair. Lets see what Trevor comes up with as he will have done this before.
Ron, I have only ever tried to fit an Indian casting once. My mate wanted me to fit a centre stand to his 47 plunger Norton he had brought this cast stand on eBay from India. Looking at it, it was the biggest pile of scrap ever. It was cast in brittle iron using a bent damaged stand as a pattern, the pattern was minus its little lug to hook the return spring over. So the new stand came out bent slighty smaller and no spring lug. Machining it was awkward as it was full of pot hard bits of iron that blunted your tools. It went on but i would never fit one again and told him how bad it was, i should never have fitted it.

Tim W

email (option): t.j.walker@btinternet.com

Re: rear stand

It is possible a mixture of materials/processes were used to produce the various frame lugs...

However, malleable iron castings have very similar properties to a mild steel after heat treatment and do not have the weakness in smaller cross sections associated with grey cast iron...

My experience in production engineering tends to make me think malleable castings would be the most likely choice...Forgings would have been very expensive in comparison and wouldn't really be necessary for the application...

BSA published technical material would answer the question definitively...General advertising literature was printed before the days of the 'Trade description Act' so even that cannot be fully relied on...Manufacturers frequently 'tweaked' the truth to make the product sound better....

A good example of that is the quoted ground clearance figures for a trials Gold Star..and the photos taken with the suspension at maximum travel!

Personally. in some cases I am wary of opinion that isn't backed up with documentation as discerning the material type and method used is more or less impossible visually....It's like trying to guess surface hardness on a heat treated component...Ian

email (option): ian@wright52.plus.com

Re: rear stand

Ian Wright
I haven't been able to turn up any original BSA documentary evidence to determine whether frame lugs etc. were forged or cast, or manufactured from steel or malleable cast iron...

From a cost point of view castings would have been vastly cheaper than forgings...Additionally, the forging process is not well suited to producing the thin wall sections of many of the lugs...However, BSA had the facilities and sometimes didn't make the logical choice...But they also had an extensive capacity to produce 'standard' and 'special' castings via their many subsidiary companies....

The industry standard seems to have been based around heat treated iron castings and assuming that were the case, heating beyond about 850C would not be desirable...So welding and/or brazing temperatures should be considered and rapid quenching avoided.. Brazing is carried out below 850C, I don't know about the various welding techniques....I have to say I'm not an expert in this area..

Opinions vary regarding what materials were used and it is difficult to know who is right, so if anyone can come up with proof (rather than hearsay) I'd be interested to see it to answer this question...Ian
The cheap & nasty method is to try & drill a small hole.
A forging will be near impossible to drill and if you do you will get normal looking spiral swarf.
It it is iron, either plain or malleable it will be easy to drill and you get small fan shapped swarf rather like pencil shavings.
Malleable iron swarf will bend & plain cast iron will break..
The rear fork section is a forging as is the frame lug with the seat pivot in it
Steering heads are funny, some a forged from tube and others are cast seems no rhyme nor reason to it.
Generally a cast lug will be parallel sided while a forging will be tapered

email (option): bsansw1@tpg.com.au

Re: rear stand

As to costings it dependens upon the actual job and the length of the production run.
We were all taught that casting is the cheapest method of forming metal, and that is true for jobbing but not necessarily so for large production runs, particularly small items like frame lugs with thin walls which become a problem to feed.
And remember there is a lot of work in making a casting from making the patterns through to reprocessing the sand and then most will require some heat treatment.

Also remember there are a lot of different types of forging and forging frame lugs with tapered ends is quite easy using open dies as a back extrusion process.
Ideally any joint in tension should be a forging while casings should only be used where the stresses are compressive.

email (option): bsansw1@tpg.com.au

Re: rear stand

trevor
As to costings it dependens upon the actual job and the length of the production run.
We were all taught that casting is the cheapest method of forming metal, and that is true for jobbing but not necessarily so for large production runs, particularly small items like frame lugs with thin walls which become a problem to feed.
And remember there is a lot of work in making a casting from making the patterns through to reprocessing the sand and then most will require some heat treatment.

Also remember there are a lot of different types of forging and forging frame lugs with tapered ends is quite easy using open dies as a back extrusion process.
Ideally any joint in tension should be a forging while casings should only be used where the stresses are compressive.
Well thanks Trevor, that awnsers my question on the material of the rear frame/stand lug before i carry out the repair to the damaged stand pivots. I will remember a forging for tension and casting for compressive forces, makes sense.
I plan to mill out the damaged stand pivot holes in the frame forging and braze in a threaded bush then weld the worn frame stand stops to get the stand at the correct angle. I will also pay attention to the swarf when I mill the frame lug.
Thanks also Ian for you input into this.

Tim W

email (option): t.j.walker@btinternet.com

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