Bitsa this, bitsa that. Poppy's non standard 1949 A7

[bikerjohndavies]

For example I have in a box of spare parts a pair of early fork legs from an early A7 rigid.

Good to know, thank you.

I didn't know the A7 went back as far as a rigid frame. After a quick google, I have to say they're pretty damn cute!

and there were even two types of long stroke rigid A7, one had a single piece frame, and one a two piece (bolted together, (like the plunger frame....I think).

Hi and welcome aboard. The 2 part frame started in 49 when there was the option of rigid or plunger frames. The front section was the same, they just bolted on the correct rear section for plunger or rigid. The forks also changed in 49 to the front and rear stay lugs on the sliders as mentioned earlier. Prior to 49 the front and rear wheel had been QD (quickly detachable) and interchangeable which meant different fork yokes as well with a wider gap.
Here are a couple of pictures of the 49 rigid I used to own before, for some mad reason, I moved it on to make way for another bike in the shed.

[Swarfcut]

  Hi Poppy. It's certainly a parts bin special you have there. The frame is the later two part bolt up jobbie as outlined by BikerJD, so all the later tinware and appropriate forks and wheels will fit and are still available with a choice of new, repro or used.
 The engine is the real problem. Parts for this are not as rare as folks think, but certainly some parts will take some finding or a bit of lateral thinking and adaption, all par for the course in a normal custom build. The gearbox looks to be a standard Plunger Frame type from a post 1951, so internals for this are readily available.

 For starters you need the front engine mounting plates....these are unique to the Longstroke Motor. You also need a dynamo, and the drive chain for this is not the standard length used on the later models. Some of the gaskets are different, notably head, rocker, cylinder base and timing covers. The major castings, crank, rods, pistons all differ from the later design. Oiltank looks to be the correct shape, but sadly the correct mountings have been butchered. The oil feed is the one from under the tank, from the big banjo fitting which is secured by the outlet filter. The return is the pipe visible on the front (now side) of the tank. This pipe normally has a T off for the rocker feed.

 Swarfy.

   

[Big_Ben]

Thank you for that, especially for being so specific.

I'm mechanically minded, but this is new territory for me, so please everyone feel free to spell stuff out!

 

[Swarfcut]

 Take some time to explore the Forum. There is a huge amount of information available along with real life experiences of what such a simple design can do to cause sleepless nights, exasperation and mental anguish to even the most hardy soul. Then there's the Longstroke......!

 Arrange finance now and dig out Grandad's Spanners. Modern ones don't fit.

 Welcome along.

 Swarfy.

[chaterlea25]

Hi and welcome!!
Zooming in on your pics it looks like untrimmed gaskets poking out rather than goo ?
I see that there are those soft crap insulating spacers on the inlet manifold
Best got rid of in my opinion as they can easily distort the carb and manifold!!
Get a solid tufnol spacer for the carb and paper gaskets between manifold and head..
The oil tank is turned 90 deg for some reason?? So you cannot check the oil return easily ??

John

[Greybeard]

I've got to say, at my stage of life I would not have bought this bike even if it was cheap. I would want to restore it to original spec and that would be a bum-ache! 😁 Good luck with it.

It is vital that you search here and on YouTube for the term 'sludge trap' ASAP.

[Big_Ben]

I have a freshly restored airhead BMW, so this is a toy for tinkering with.

I doubt I'll put it back to standard, but maybe more period (forks etc).

At the moment, it's a choice of two routes although that may change as I start to delve into what I've got.

a) Most likely, semi-period bobber build, period registration number. Nothing silly, maybe a lary paint job.

b) Q plate, change the colour of the gold anodizing to something more fitting. Sort out the badly done bits and ride the bugger.

c) Full restoration to standard - highly unlikely.

[BigJim]

b) Sounds good to me. Get the pipes blued and the engine sorted before you spend a fortune chasing rare cycle parts. You can't see the number plate when you're riding it. Will also be nice to have good brakes whilst your checking engine and frame for straight etc.
 

[scotty]

Welcome Poppy

What a contraption you have there !……..hours of fun whatever you decide to do with it

S

[olev]

Gday Poppy,
I think it looks great. The original bikes were called 'grey porridge' for a reason. That things got character.
I'd leave the brakes, seat and front forks as is. They are way better than anything BSA ever made.
Your electrics are the biggest challenge.
or just paint the forks black, stick on a small alloy front guard and ride it like you stole it.
cheers

[Rex]

I don't think I've ever heard of the A7/10 bikes being referred to as "grey porridge"  before 
Mundane ride-to-work 250's maybe, but not a BSA big twin.

[Big_Ben]

Ha ha, lots to consider.

Definitely a key point here is that I'll need to get it registered.

Pre '73 (?) bikes came used a black and silver or black and white number plate, then they switched to yellow and black.

I'd need to fit it with semi-standard wheels and forks to get an age related registration and plate, even if I then changed it back to the modern gear. If I try to register it like this, I'll have a Q plate which I think means age unknown / multiple doners etc. Q plates are to be avoided if at all possible.

At this time, top of my concerns is to get it registered with an age related number.

Either way I've a lot of work to do on the beast.

Anyone UK got a set of forks and wheels they want to lend me?

 

Also... Grey porridge!

 

[Greybeard]

Considering that even my humble plunger has a very pleasant performance I cannot agree with the description that our bikes are 'grey porridge'. 🤔

[Swarfcut]

 I'm just having a closer look at the set up. All looks newly assembled, with possibly a brand new carb, new nuts and at least a nicely cleaned up set of castings. Maggy looks to be a good example, a late type with screw on end cap, not the usual oily battle scarred example often found. Nice kink on that oil return to the tank.

 Big BUT here is that to fit the right hand plate and dynamo strap holding pins (simple 1/4" bar with Whitworth thread at one end) the inner timing cover has to come off, and to fit the right hand front mounting plate the whole engine and gearbox must be lifted and swiveled to position the plate. An engine crane or 6 hands should do it. Then you can replace the timing covers.

 GB mentioned the SLUDGE TRAP. Don't get paranoid, but this really is the single most important aspect of long engine life. Here's one I made earlier, this crankcase is the later type plunger. The plug was a devil to remove, had to get the gas axe, hence the heat mark.

 Sleep well.

 Swarfy


 Additional. The Longstroke has a smoothness lacking in the later shortstroke motor, and with low down torque makes a pleasant cruiser. A road burner it ain't, but will roll easily solo with a 42 tooth rear sprocket and 20 teeth on the gearbox. They were dismissed as being a bit slow, as being often used as a sidecar bike, usually found with the 49 tooth dinner plate and 18 tooth gearbox cog giving plenty of low end power but a lower top speed.

[bikerjohndavies]

As Swarfy mentioned earlier, you'll need a set of front engine plates which are different to the later short stroke engine with the holes being in different positions. Here is a picture of plates and measurements.