In the Beginning…
One my earliest memories, one of those mental snapshots from the past was a view, sitting on my Mum’s lap, out of the window of a double adult sidecar. I must have been about 3. The sidecar was attached to a BSA M21 owned by my Dad’s brother Mike, who was an art master & amateur opera singer from Woking in Surrey. The M21 was used as family transport for Mike, my aunt Doreen and their children before it was replaced like so many others by a Morris 1000.
Years later, when I had kids of my own and was re-discovering the wonderful world of old bikes, Mike used to visit us in Norfolk. I learned that before he bought the M21, he had had a Bantam D1, just like the one on the front of the first edition Haynes manual that I had in my motoring library.
A seed was sown.
A bit of history
But what does this mean?
After World War II, in accordance with agreements made at the Potsdam conference held between July 17 and August 2, 1945, Germany was made to pay the allied nations US$20 billion, mainly in machinery and manufacturing plants. In addition, in accordance with the agreed-upon policy of the de-industrialisation and pastoralization of Germany, large numbers of civilian factories were dismantled for transport to France and the UK, or simply destroyed.
In the end, war victims in many countries were compensated by the property of Germans that were expelled after World War II. Dismantling in the west stopped in 1950, though reparations to the Soviet Union continued until 1953.
The BSA designers converted the design for the British market, including Imperial measurements, fasteners, & bought-in components for manufacture in Birmingham and the most obvious change, the inversion of the whole engine for the right-foot gear change. The engine proved itself, and with small motorcycles becoming ever more popular in Britain, BSA decided to build a complete motorcycle around the D1 engine.
This original Bantam, the D1, was released in October 1948 and continued in production for several years, initially for export only. It had telescopic forks, a rigid rear end, direct electrics, shovel front-mudguard and a fishtail silencer. It was available only in "mist green" and sold for £60 plus purchase tax. Although the frame changed out of all recognition (beginning with conversion to plunger and then swinging fork rear suspension), the engine remained a recognisable development of the original for the entire 23 years of production.
The engine was a unit construction single cylinder 2 stroke, with a cast iron barrel and alloy cylinder head. The gearbox was initially provided three speeds, fed through a "wet" multi-plate clutch and the little bike would get to about 45 mph, returning about 100 mpg.
Carburetion was provided with a simple single-jet Amal carburettor, typical of those fitted to small machines at the time, with a simple oiled mesh air filter & strangler. The early D1s had one piece "fish tail" styled exhausts but this was replaced with the more conventional cylindrical silencer which could be dismantled for cleaning – which, in the days when two-stroke engines ran on conventional mineral oil, or even what your Dad drained from the sump of his new Morris Minor, was highly desirable. Brakes were highly conventional 5” pressed steel drums which were considered adequate at the time.
Although the bike had its fair share of faults, it sold well and became a common sight on the roads of Britain. One thing BSA had not expected was its introduction into competition events. Owners modified their bantams, fitting non-standard sprockets and wider handlebars. The Bantam was one of the first bikes to be used in this way, trials before that had been more professional events run by substantially larger bikes.
Some of the deficiencies in the original design were tackled in 1950. The D1 was now offered with plunger rear-springing in addition to the rigid frame version, a welcome relief to the backsides of Bantam owners. This was a major change to the frame, and altered many of the associated parts.
The 27 Watt Geni-Mag was replaced by two options, a Wico-Pacy Series 55 30 Watt generator, and a Lucas IA45 45 Watt Alternator. The Series 55 was the next development of the Geni-mag, more powerful, more reliable, while the Lucas was completely new. The system incorporated an external ignition coil, powered by a battery. Being a DC system it also used a Selenium rectifier and was electrically much more complex than the Series 55.
Rubber Gaiters were added to the front forks to prevent debris from interfering with the motion of the forks. The exhaust pipe was routed above the footrests, which gavean overall more pleasant line to the bike.
The rather flimsy headlamp bracket was replaced by a steel pressed steel shroud, improving the look of the bike if rendering cable replacement a little more difficult.
The use of Bantams in the competition events had not gone unnoticed by BSA, and they released both rigid and plunger bikes as specific competition models. Many changes were made to these models, the most noticeable fitting the silencer in an upswept position and a folding-kickstart. The cylinder head had a second hole for a decompressor to be fitted for reducing engine braking on downhill sections.
In addition, the front suspension was made more substantial through the use of larger diameter stanchions and the cylinder was not simply bored out but was enlarged with distinctive larger thermal cooling fins. All post-1953 bikes, including D1s, are immediately recognisable by their larger finned cylinder barrels and heads, improving cooling although they maintained their smaller bore.
The bike was fitted with a beefier front brake and was painted a pleasant grey colour, which is the easiest way to spot a D3. The larger capacity rocketed power from 4 to 4.9 horse power, sacrificing a little economy in the process.
The bike was in Nottingham, and as luck would have it I was working in Leeds at the time and so was easy to pick the bike up on the way home. So one Thursday afternoon in August 2009 I turned up with a white transit van to meet Pete & his delightful springer spaniel. Pete had had an unfortunate time with a brain tumour and didn’t want to risk his health with a bike project, so after tea, a long chat and a poke around the bike we loaded it onto the van. Pete even found a new single seat still in its box.
Once home and out of the van, my daughter Harriet & her friend Florence pushed our new project into the garden, so we could get a good look at it.
So! First job, the carburettor. This was the first pre-monobloc carburettor I’d had my fingers in, but I guess I wasn’t surprised by the fact that most of the petrol in the carburettor was actually inside the float...
I was a bit wary of this. It was obvious that the float was made in two halves, spun copper, soldered together with the float needle up the middle, and it was going to need de-soldering to drain the fuel out. So we devised a plan.
Nothing happened – except for the un-ignited petrol spraying from the soldered seam! Eventually it stopped and, as the float was still intact (or so we thought) we put it back in the bike. Petrol, kicking, new plugs & leads, followed by bump starting & swearing left us convinced the crankcase seals were shot.
So, the little Beezer was transferred to the summer house, and we took the engine out. The general idea at this point was replace the crankcase seals, attending to any other engine problems in the process, and then get the bike running. It didn’t turn out like that.
Cleaning & inspection followed, using the sink, oven & other kitchen utensils. The only curious thing was that one of the closing plates, from the timing side flywheel, was completely missing.
Well, not quite the only curious thing. A bit of nosing about with the callipers revealed that the bore was not the 52 mm that I had been led to expect by the D1 engine number, but was 57 mm – revealing the block & head to be from a D3. Checking part numbers revealed that the carburettor was also from a D3 – what luck! An extra 0.5 bhp!
Later we found that the engine was from a GPO Bantam, shipped to Bristol in 1963. It has the later main bearing lubrication holes!
Courtesy of the wonderful people at Rex Caunt Racing we changed all the seals, the primary chain, tab washers, all the engine and gearbox bearings and all the springs, the piston rings and the little end. Rex also provided a flywheel closing plate, which we riveted in place, assisted with Loctite. We also took the opportunity to clean everything and repaint the barrel.
Plating with John Wyatt
The handlebars that came with the bike were green and obviously from a direct lighting Bantam. We drilled a hole for the horn button on the handlebars & tapped 3/8” BSC, since this was a battery ignition bike with an electric horn. Later on, we sent John the original wheel rims, the handlebars, the plunger covers and the brake levers. The wheel rims have been a bit of a mixed blessing – I have original rims, but I should have realised that they would still be rusty on the inside of the bead – the every time it rains, I have rust stains on the tyres!
Frame cracks & welding with Alex
As we stripped further, a few problems started to appear. One of the worst of these was a crack in each of the footrest bar lugs, which also mount the centre stand – two lovely deep cracks filled with years of accumulated oily gunge. We toyed with the idea of grinding these out and attacking them with the trusty MIG set, but eventually the size & depth of the cracks along with the critical nature of their location put paid to that idea and we entrusted the repair to a local chap, Alex, who runs an outfit called ‘Matchless Engineering’ from his home in Norwich. Alex made a tidy job of welding the cracks up, plugged some holes and built up the centre stand stops.
The MIG set made its contribution later, when we repaired the battery carrier. The strap was completely shot, having rusted through at some point and lost most of the moving half along with the trunnions & the screw. A replacement was easily made up from some 18 SWG sheet bought from a local fab shop, along with sundry other cable clips & brackets for the horn & stop light switch.
Draganfly supplied the trunnions & the screw.
My understanding wife had, at some point in the past, bought me a £5 wrist watch from eBay – broken of course – thinking I’d enjoy tinkering with it. This blossomed into a bit of a hobby – the £5 wrist watch grew into a small collection of Omegas, bought broken, fixed & consigned to the jewellery box – so the chance to get inside a Smiths Chronometric was an in interesting challenge, if only to figure out how it worked. Most watches are pretty simple compared to these little fellas. Still, like most watches all it really needed was a clean and the spiders chasing out and with a freshly painted case it’s almost as good as new.
The next job was the glass, which had a huge crack across one corner. We made a new one, with a diamond glass cutter, from an old picture frame glass. It wasn’t half as difficult as you might think. We cut a rectangle, cut two of the corners off, and kept scribing with the diamond & nibbling the corners off with pliers. We smoothed the edges with one of those diamond sharpening stones and popped it back in the case. Jobs a good ‘un.
And all to bits...
So the strip continued. The engine was finished, still in the cellar, and we were getting past the point of repairing odds & ends and coming to pulling the whole bike apart – a very easy thing to do with a Bantam! As it came apart, we bagged up all the parts & old fasteners into labelled sandwich bags and took dozens of photographs. These were stashed in the house for attention later. We kept all the cables, the wiring harness, manky old grommets – everything.
Adam & Mike at Aerocoat
We’d slowly got to the point where everything was apart, replaced, repaired & cleaned and it had begun to feel like we were turning a corner. There were bags of old parts; boxes of new parts; an engine sitting in the cellar workshop with nothing to do. It was time to find a painter.
I’d asked around all my contacts in the trade and come up with some options, but I happened to be in the local cycle shop one day & they suggested talking to Adam at Aerocoat near Yarmouth. I contacted Adam over the phone, got a
very reasonable quote together and packed the bike in several boxes into the back of our Morris 1000. Aerocoat is based in a little unit in St. Olaves, a pretty little riverside village near Yarmouth where they do a lot of blasting & powder coating on bike parts, wheels and equipment for the oil & gas industry. They are great guys, very friendly & enthusiastic and together we decided on a suitable match for the Mist Green paint that was still on the bike. I left them with a comprehensive list of the parts, with photographs of each component and the colour it was to be and in a few weeks we returned to see the bantam stripped of all paint. They plugged all the holes & threads, and repaired one or two holes we hadn’t seen before along with a large dent in the tank.
A couple more weeks and we went back to collect a lot of very shiny green Bantam parts!
So, armed with a box of unpolished stainless fasteners we started the rebuild. The frame quickly had the centre stand & footrests added, the new ‘C-link’ & pivot made from more scrounged plate, and the brake pedal. I’d had all these bits fitted prior to painting, so there were no fears when it was finally assembled. This was followed by the rear mudguard, stays & rack and the fork yokes.
Forks again. How thick is that paint?
It was then that things slowed down. I didn’t have any of the chrome or the wheels, and I found I had some lessons to learn from the painting. I really hadn’t considered quite how thick the powder coating was – there was no way the fork legs were going to fit in the yokes, however much I spread the clamps... A rummage in the cellar produced some scraps of sapele, the hardest timber I had to hand. I made some wedges to open out the clamps in the lower yokes, and attacked the upper parts of the fork legs with some 60 grit, until I could get the legs through the bottom yoke and into tapers in the top yoke. Won’t make that mistake again!
I bought the few transfers, along with many other sundry parts, from Draganfly at Bungay in Suffolk. I applied these to the toolbox lid and the number plate/rear light unit with the aid of some spray lacquer.
Wiring up filled some of the waiting time. I bought all the parts for the new loom from VWP, and I covered the loom with expanding plastic mesh sleeving – which looks kinda like the woven cotton covering BSA used, if you don’t look too hard. I used 2.5 mm2 cable throughout, and I provided earth cables to the rear light, the head light, and one of the handlebar clamps and I tied them all down to a common point on the frame, under the tank so that the frame was not used for earthing at all. I fitted a modern rectifier and one of Paul Goff’s 6V halogen headlamps, but the parts I was most pleased with were the original Wipac headlamp switch, dip switch and horn button I bought from Malcolm Leech. I still have to find an original Wipac stop light switch. Michael Cushion had one fitted to his Bantam but he wouldn’t sell it to me!
There’s a lot written about pattern parts in the forums these days. The only problem that I really had in this direction was with the headlamp glass & reflector – which just didn’t fit in the original rim. Instead of sending it back, I cut the new reflector away from the glass and mated it to the old glass, sticking it in place with Silicone RTV. It all works fine but says ‘Bosch’ on the glass!
I stripped the original Wipac rear lamp, cleaning, polishing & replacing seals as I went along. The horn came from eBay, off a C11 I imagine (it was maroon) and was stripped, cleaned & painted. It works after a fashion.
Wheels. Which way round does that rim go?
Wheel building, I discovered, is not that difficult. My son pulled a 1960's Raleigh out of a skip, which some hooligan had robbed of most of its spokes, and rebuilt it for his sister to use. Following his example, I’d set about Beattie's wheels with my bolt cutters and left the rims at Wyatt’s in Thetford. I took lots of pictures, drew a sketch & measured the offset – I even made a jig to set the offset when I got the bits back.
I’d bought stainless spokes & nickel plated nipples from CWC. Excellent stuff. With the hubs powder coated, new bearings and the spindles back in, I set up the front wheel in my building jig & set about threading the spokes in & putting nipples on. All went well with the front wheel and it trued up nicely on my homemade truing jig.
The back went together almost as quickly, but is a bit easier as all spokes are full length and are a bit more flexible. After a few, I realised it was a lot easier to put the nipples on first, as all the spokes have keyholes in the hub flange. I got that one trued up as well, when my son Tom came into the cellar workshop & enquired as to why the spokes were all bent! It was one of those moments when you realise something had been wrong all along.
I’d got the rim on the wrong way round. Start again time.
So the next thing we needed was some tyres. On the web, I found some 2.75 x 19" tyres in nearby Fritton, where we met Michael Cushion who runs an eBay shop and a stall at various autojumbles around the country. Michael showed us around his workshop, where he is building a Calthorpe (??) from the 20’s. Amazing attention to detail! He’d made some press tools for manufacturing the footboards, by welding dozens of tiny diamond shapes to a plate to produce a checkerboard pattern in the sheet metal footboard.
We bought some tyres, and some footrest & pedal rubbers, and some handlebar grips. We fitted the tyres when we got home over the old tubes & some rim tapes made from bicycle inner tubes. We’d be seeing these again sooner than expected.
Back to VWP’s website saw me buying cables, ferrules & nipples. I made a simple tool from two pieces of ½” square bar to swage the nipples to the cable outer casing and to form the inners to bell them out, to avoid them pulling through the nipples. These were soft-soldered up and soon the cables were done. I made a similar tool to swage the ferrules on the petrol pipe.
And that was it really. With the wiring done and the wheels finished it could all go back together. We took the frame & forks outside as an assembly, and fitted the wheels, and dropped the engine in. An afternoon’s work saw it assume its place in the bike shed.
Danny D’s – a long walk
Unfortunately, due to a small oversight with a spacer (or lack of) on the front wheel spindle, the forks were locked solid and the MOT wasn’t forthcoming that day. It was an easy fix though, and that weekend saw me back at Danny’s with another appointment, this time resulting in an MOT certificate. It was an exciting, if short, ride to Danny’s place as I’d not ridden a bike on the road for years. The trip back was a bit more eventful – about half way home I’d just ridden through a pedestrian crossing when there was an almighty bang, followed by a clatter and a deafening roar from the engine (allow me some artistic license here!). I stopped and looked back to see an old chap on the crossing, searching the sky for the ships of the Vogon Constructor Fleet arriving to demolish the earth, with my silencer at his feet.
So, it was retrieved and the loose baffles re-inserted into their erstwhile chromium plated tube, aided by my size 9s. A few yards down the road it became apparent that Beattie was attempting to consume rather more fuel than she should, and when the engine finally died the stream emanating from the carburettor overflow signalled my abject failure to repair the hole in the carburettor float.
My my! Weren’t the family amused when I arrived home in full riding gear, drenched with sweat and pushing a dead (but MOT’d) Bantam! How they did titter! A new exhaust system was called for.
DVLA & the BSAOC
The next job was to get the legal bits sorted out. I had been in touch with Steve Foden at the BSAOC a few times since I’d had the Bantam and was a bit concerned that Steve had not yet managed to find any records of my frame number amongst 500,000 others. Steve said that it was not uncommon for frame numbers to be missing from the record. Normally each machine was recorded in the despatch record by frame & engine number along with the receiving dealer but if, after assembly & test, the machine was found to be faulty it was corrected off-line and despatched from the rectification department. These machines were not listed in the despatch record.
So, as my frame number did not appear in the record, Steve dated it from frame numbers greater and less than mine, which were all shipped in May 1954. Unfortunately, the local Norwich DVLA office, who are very nice helpful people by the way, weren’t having any of this and would only issue a Q plate.
So be it. I decided to tackle that problem later and taxed the bike for £15. Unfortunately, returning home I found that the £30 insurance policy I had bought to get my MOT turned into a £70 insurance policy (with a new insurer, and no rebate on the old one) for a bike with a Q plate.
Later – post running mods
And so began a wonderful relationship. We spent the next few weeks pottering about, tinkering with brakes, ignition timing, and fixing the last few bits and pieces. Most of the time I spent trying to get the carburetion right – it would either start, run in the mid-range, or race away to 50 mph but it wouldn’t do all three. A bit of research with the Amal carburettor manual revealed that the D3 had been fitted with many different main jets, slides, and needle positions over its life and I tried them all. Several times.
Right to this day I’m not sure it’s right, but I’ve just reset the carburettor float height again and repaired the float again – there was just a small amount of fuel in it, which would make it heavy & raise the fuel level. I’m hoping this was enough to upset the mid-range but we’ll see.
There was fun & puzzlement with brakes. Some while back I’d had a set of shoes made to measure for the front brake -with soft linings which fit & bite well -from 'Charles Johnson -Bus & Truck Parts' in Norwich.
One sunny Sunday afternoon, racing through the Norfolk countryside, I was going up a small hill, when she slowed down as usual, but on the other side she wouldn't pick up again. I dropped a gear, but she was still very sluggish. I coasted to the side of the road, as I fancied the engine was noisier than usual but as soon as I stopped I realised the engine was ticking over fine.
Then I realised there was a strange smell - of the hot clutch/brake pad variety. Getting off, there was SMOKE coming from the rear brake! So I slackened it off at the roadside, and when I got it home I twigged that I had put the arm on the wrong spline -so I moved it and now I had clearance, better leverage (90 degree angle -arm to brake rod) and a brake that didn’t overheat.
However, a few days pondering & a bit more investigation and I figured out what happened.
The back brake shoes were way too small in diameter. I'd adjusted them up so much, to make the pedal travel pretty small, that when I put the brake on the cam went almost 'over centre' & jammed, holding the brake on. That's why it happened suddenly, away from home. I must have braked for something.
Yet another Bantam morality tale. This time, the lesson is to make sure the brake shoes fit the drums! The ones I had in there were virtually new off the shelf shoes from one of the main suppliers...
Of course, the other problem I had built in was the ability for the tyres to go flat on their own. Schoolboy error – never fit new tyres to old tubes!
I tried to make it as original as possible during the rebuild – I’d found some chrome tank strips on eBay, for example, and I’d made sure to find a dip switch that matched the picture in my 1953 copy of Haycraft’s “Book of the Bantam” but one of the items I found I really missed was a side stand. eBay to the rescue again, along with some longer engine bolts and a little extra clearance courtesy of a flap wheel and we were in business.
As I built the kit up I did all the maintenance & repairs with it and eventually I had enough kit in the bike’s toolbox to do pretty well anything I needed. Easy maintenance is one of the great things about old bikes – but I guess none of you need convincing of that. No electronics, no hydraulics, no cooling system, no fuel injection and it is all so accessible you can do the work in minutes.
Howard, the Bantam club & back to the DVLA
I'd got to the stage of considering applying for 'reconstructed classic' status, when Howard called me at work. I was glad to be dragged out of that meeting! Howard had been doing a bit of lateral thinking, and had realised that most of the frame numbers around mine had been D3s -so he'd looked in the D3 register and found it -shipped in May 1954 to a dealer in Southampton!
One last thing, hoping that some of you may be inspired to get out & about on one of these little bikes, and that is the fantastic Bantam Owners Club forum. Out there in the ether is a host of folks talking online about all things Bantam – post your problems, share experiences, maybe even find parts or a new bike – there is always someone to help you. Find it at http://www.bsabantamclub.com/forum.
So what’s next?
It’s a happy little machine though – puttering along Norfolk roads at 35 mph while I enjoy the sunshine, running made-up errands to the shops... So what next? Something a little quicker? Something Mrs H can ride on the back? Something that will go up hills? Despite Noel coward’s sentiments, we do have them in Norfolk...
I have my 50th birthday coming up. A nice lady from Essex has bought a van full of parts that supposedly make a machine called an ‘Ariel Square Four’....
Rex Caunt Racing, for the engine spares (01455 846963)
JD Wyatt Polishing for all the chrome work (01842 766770)
Adam & Mike at Aerocoat (01493 488455) http://www.aerocoat.net/
Mike Peters at http://www.polished-stainless.co.uk/
Alex at Matchless Engineering (01603 630180), for the frame welding
'Charles Johnson -Bus & Truck Parts' in Norwich (01603 485429) for relining the brakes
Malcolm Leech (0121 559 7306)
Michael Cushion email@example.com
Draganfly (01986 894798)
Len Baker (01502 724488)
CWC (01675 462264)