Here are some notes from the previous owner, Roger Bean
of Co. Durham.
Well, it used to be mine, as a collection of assorted rusty bits, and boxes
and packets of new parts purchased 'at the right price' over
some twenty years, pending an eventual start on my 'Project bike'
- my ideal B31/2 derivative - light, nimble and quick, built for back-roads
scratching, and incorporating desirable features from other BSA models (e.g.
larger oil tank and proper oil filtration).
With the additional purchase of another frame, there were
enough bits to build a spare bike (albeit with an iron engine). I'd
been collecting bits to build this special for nearly thirty years, by which
time I concluded that I was too physically fragile to wish to ride rigid
framed bikes any more. Twenty miles recently, on a 1939 M23 had convinced
me of that! The new owner, Martin Wheeler, has chosen almost all the bits
from the assortment that I'd have chosen myself to put together a very pretty
little special exactly as I'd always imagined it.
I had considered a number of options for it over the years,
a Trials model would have had a smaller tank (but still too big for trials
at 3 gallons), 21'' front wheel with 7'' brake and chromed brake plate
which would engage in the boss visible at lower rear of the fork leg, non
standard gear ratios, very flat chromed mudguards, smaller oil tank, tool
box filling lower rear triangle of frame, trials 'bars of course, and other
The road - going ZB32 Special, as shown features the following
OUTSIDE : frame/tinware etc.
rare, plunger sprung Gold Star'optional accessory' 4 gallon
TT special tank
pint oil tank with felt oil filter - fitting of which necessitated using
a non standard (BSA) toolbox from a 1930s model.
accessory sprung dualseat. (I think I may have preferred a single saddle
but this dualseat is really well sprung.)
Commando mudguards (ignore the reflector on the front one - there's a
story behind that!)
(fitting of which necessitated some modification to the R/H crankshaft.)
INSIDE : ZB32A engine
flywheels (When found, these seriously modified BSA flywheels had a Matchless
G50 con rod fitted, with a sleeve in the big end eye to accept the smaller
diameter BSA bearing) a pre-war BSA forged high compression piston with
alloy end caps in the gudgeon pin.
high -lift cams from a selection I had acquired over the years (road
racing and scrambles, and an unclassified one, quite mild compared with
the others, but noticeably higher than the standard item). [Martin:
I sourced and fitted genuine Gold Star touring cams].
crankshaft, being an early type, had to be modified to suit the timing chest
cover which supported the rev-counter drive.
other bits I'm not aware of?
Martin seems to have built it choosing almost all the special
bits I'd have chosen myself. It took a long time to collect non-standard
parts that would be compatible with each other and 'look right'
when fitted. I think he's done a superb job, and I now wish I'd got round
to it myself. It's a shame it's now so far away, I shall probably never
see it, let alone ride it.
The story behind the front mudguard reflector is that in
the early nineties the mudguard was fitted by me to my 1948 VP Viper sports
sidecar, attached to a pal's Thunderbird to do the Beamish Trial. I was
careful to fabricate mounting brackets to use existing holes in the mudguard
so as not to spoil it for it's ultimate intended fitting to the ZB32. Pal
Brian drove away with the outfit, and being worried about legality of having
no sidecar lamp, decided that a reflector would be better than nothing and
without consulting me, drilled a hole in my mudguard for a reflector! I
was furious. (If I were you Martin I'd replace it with a chrome bumper
bolt from a car, or even just a rubber blanking grommet - and mount the
front stays further forward please.)
Use of the more efficient M20 oil tank with felt oil filter
instead of the useless gauze strainer of the standard tank meant I had to
find the model with a hole through it in which to route the speedometer
cable, driven from the top of the gearbox. The alternative tank meant that
the standard toolbox would not fit so a suitable 1930s model was sought.
The alternative toolbox along with the big oil tank, TT petrol tank and
carb really enhance its appearance. There was an original type (unused
though rusty) silencer with the 'job lot' (I use the
expression 'silencer' advisedly, since it was so light it can't have contained
much in the way of baffles - more of an expansion box, it might have enhanced
the performance - and noise?) I thought Martin might have seen fit to
re-chrome it. I notice he's fitted a silencer for the plunger, rather than
the rigid framed models with an ungainly bracket, (that little bracket
at the tail end mounts to the pinch bolt at the bottom of the plunger unit).
The correct silencer has a built in short bracket that mounts direct to
the pillion footrest bolt. I'd have preferred the 'Spring green'
on the tank rather than the darker 'Brunswick green' but this
is just preference, as I say, it looks bloody marvellous, it really does.
I'd love to hear of any particular problems he encountered
along the way, I seem to recall there was to be some modification involved
in the oil feed to the big end if the rev-counter timing case was to be
used? Which combination of cams did you use? [Martin replies -'Gold
Star Touring']. Was there sufficient clearance for the higher comp
piston? Does the engine 'pink'? The reconditioned TT carb
was supposedly ready jetted for that engine - was it OK? The mag and dyno
were both already overhauled by FTW in Sheffield did they work OK? (Dynamos
sometimes lose polarity if left unused, and appear not to work initially,
re-polarising takes only a few seconds if you know which wires to swap momentarily.)
How does it go? I had visions of sweet, smooth and brisk
performance, rather than a rorty roadburner. A B31 is flat out at about
70 per, I envisaged 80-ish from the B32, possibly approaching 90, but I'd
have been happy at a genuine 80+, enabling easy cruising at around 65, gearing
arranged to suit, with a surprising burst of acceleration to amaze the un-knowledgeable.
I hope it works out that way when it's run in properly. What effect has
the lightened flywheel assembly? When I salvaged those flywheels they were
fitted with a shorter G50 Matchless conrod, in a BB31 bottom end overstamped
as DBD34, so somebody had been up to daring deeds with them! How do you
get on with the lack of a tickover setting on the TT carb? Being a racing
unit it is meant to shut down and die if you let go of the twistgrip. I
trust you don't annoy the neighbours with too much throttle blipping? (However
wonderful it sounds to our ears.)
Handling should be fine, the original BSA set-up steered very true in the
case of that model, and you had all the ingredients for a first class set
of forks? - Perhaps I may see or hear it running some day?
Regards, Roger Bean.
Well Roger Bean, nice to hear from you. As you can see at last I have a
very nice ZB32 Special. A one off called 'Grace' (white
letters in script just before GS stars on tank) not seen in this photo.
The DVLA supplied me with a nice age related No. from Alloa. Good to hear
you approve of the way I built the bike up, the dual seat was the only concession
to my wife, can't see her throwing a leg over a bum pad. The dual seat is
a genuine plunger one re upholstered and sprung by me. It does not look
out of place and is very comfortable. I did not use the Omega 9:1 piston
in the end the bore had to be taken to max and I used the Empire Star piston
with the floating end caps. Flywheels seem fine, the engineer I use [John
Clayton] did wonder where all the worm holes had come from. (They were
obviously turned down to clear the skirt of whatever piston was fitted to
the much shorter G50 rod - all I acquired was the bottom end with a non
standard rod peeping out - the big-end had seized - big time!) - Roger.
The forks are re-bushed/sprung and feel as-new, they work
fine, as you have noticed I have left the boss in place and reversed the
8'' brake bar forward as they did in the States. This is because when I
get around to it I might fit the 21'' for a bit of off road riding. Silencer
used is a genuine one off my shelf, and sounds fine - I am toying with putting
on the GS strait through. Yes, the problem with the later timing case was
overcome by club member [John Clayton] 'he's a clever chap'.
The rev counter was wrong, winds wrong way, John also sorted that and other
problems - (SORRY - I really didn't know that, as a matter of interest
it was fitted originally to a racing Vincent sidecar outfit- ROGER).
I'm getting it sorted - Mag and Dyno I re-overhauled. (Didn't
trust me huh? - Roger)
The TT carb was a problem while running in, (I'll have another go later)
I fitted a pre mono off my ZB31. It runs fine but a little rich at the moment,
losing power on the top end. I have fitted genuine GS touring cams. Starting
is without a decompressor as one supplied and fitted was badly worn and
(I've never ever known a BSA valve lifter not to work
- you must be overlooking something - try moving the short arm to a different
spline, and adjust the cable if necessary. They don't wear out because they
only bear on the back of the rocker arm when you pull the trigger, the spring
on the cable keeps the cam disengaged during running. I'll check my stock
and send you another handlebar lever 'trigger' if possible. When
used correctly - and very few folk do,- even oldtimer die-hards -, the valve
lifter enables you to start the engine from compression with a genuinely
effortless swing. I will explain in greater detail when I am sure you have
it set up correctly. There is no pattern part for the valve lifter cam assembly,
only the handlebar 'trigger', which should be positioned to be used
by your left thumb, making sure that the clutch lever clamp does not foul
full travel of the valve lifter trigger - ROGER).
She does get stuck on the top of the cam 'put in
2nd gear and move wheel backwards' does the trick, one big swinging
kick usually gets her going. I have been very careful in running in 500+
miles so far. Not fast off the grid as I have geared high for touring spec
with an 18 tooth engine sprocket. (46/47 B31 used 16T, 48> on used
17T as standard, so 18T should be right for your state of tune, as you say,
long legged.) This bike has 'Long Legs'once in its stride
it just limbers along no effort at 55/65 miles an hour. I'm convinced when
run in and sorted this bike will do 80+.
You never know - I might take a long ride some day! (and
I might visit you one day and steal it for a while - ROGER)