1969 B441 Victor Special frame.

[nickdun]

Hi All
It's been a long time since I owned a unit single (C15 in the 1980s) but I've recently bought a re-patriated B44 VS to restore.  I had to get some work done on the footrests of the frame.  The footrest mounts on the frame are attached above the rail on the left and below on the right.  This seems to be consistent with photos of other 1969-70 model year bikes I have seen, but the frame had a crack ahead of the RHS footpeg mount.  When the frame was cut to remove the damaged area ahead of repair, the frame was found to be double walled.  The double tube arrangement went fully along the bottom (at least) of the frame rail.  I can only conclude that this must have been a factory installation, and I wonder if anyone could enlighten me as to why BSA did this and was it a common feature on their frames?

[AWJDThumper]

The so-called welded duplex frames made by BSA and used on the B44 were strengthened under both the engine and under the seat with an inner steel tube. Not entirely sure why they did it this way rather than simply increasing the gauge of the outer tube. 

[nickdun]

Thanks Mr Thumper I did not know that.  I'd heard of duplex frames but didn't realise I had one!  I bet it was done like that for cost reasons.  I bet it was cheaper to bung telescoping tube in than to buy a thicker walled tube in the first place.  Also easier to braze less heat transfer?

[AWJDThumper]

Despite them being referred to as the welded duplex frames, they still used brazing for the footrest and side stand lugs which were weak points. I had to repair the side stand lugs on both my B44VS and B40WD due to failure of the brazing.

[nickdun]

Snap I've had exactly the same issues with my Victor Special.  Failed braze and cracked frame.

[nickdun]

Can any one help with the battery tray in my VS?  The bike came with an energy transfer system and I'd like to return it to standard (already hard enough to start without an intermittent spark!)  Is the battery tray mounted at an angle?  Looking at the fixing holes I assume it can only be mounted that way.  It had some capacitors screwed to the mounting holes below the toolbox, I assume they're in lieu of a battery?

Thanks

Nick

[ducati2242]

if is the same as my 67 then it is level

[nickdun]

Sorry Mr D (and thanks for the kind reply) i of course didn't mean sloping as in level I meant parallel to the end of the air filter box and not the swing arm pin.  Mine seems to be like that and I hope it's normally the case, otherwise I have the wrong battery tray.

Ta

Nick

[ducati2242]

This is mine . It isn't parallel to the swing arm.

[nickdun]

Great cheers thanks.  Mine's exactly like that.  Thanks for the pictures and taking the time to help.
Cheers  Nick.

[MICKREEVES]

My B44, 1969. vibrates badly at all revs, I had a new bigend and balance check form Alpha. still the same.
Is this normal for this model?
Mick

[AWJDThumper]

All unit BSA singles vibrate to some extent but it shouldn't vibrate so badly that it is unpleasant to ride. Are you sure it isn't due to a problem with the engine mounting or the head steady? Also, running with too rich a mixture or too advanced ignition timing can result in unpleasant lumpy running.

[MICKREEVES]

Yes, mine is a THUMPER! at all revs. All mountings are secure, I stripped the engine for a new bid end. Nothing seemed awry.
.I forgot to note whether it had been re bored.Would the heavier piston make a difference?
I hope to find another owner of a B44 to compare with. It starts, first kick every time, accelerates well up to 90 MPH.
Mick

[nickdun]

Morning all.  My bike had an energy transfer system fitted when I bought it so I have had to buy a battery tray.  Could anyone post me a picture of how the 3 bolts that secure the tray to the frame are arranged?  There's a selection of rubbers and distance pieces and I'd like to be clear how they are assembled.  Also the two 5/16'' BSC shouldered bolts (part no. 40-4530) seem to be unobtainable.  Does anyone have the dimensions of one so I can make a pair?

Thanks in advance.

[AWJDThumper]

The 3 bolts with rubbers and spacers are shown below: