BSA Three-wheeler Van Reconstruction
(The only BSA three-wheeler van in the world)
Talented engineers don’t come our way very often, that’s why, when one does, his work deserves to be shown to the world. Mike Scott-Coomber told his story exactly as it appeared in the October, November, and December 2000 issues of our club magazine, sadly Mike died quite suddenly in 2008 so this is a tribute to him and all the good work he did for this club, he was admired and respected by everyone he met and had dealings with.
This article dealing with van reconstruction may be a bit irrelevant to most members who will have no intention of producing one. However, I hope some of the details may be helpful in work on the more conventional trikes, or Scouts for that matter. The first problem was that, as far as I know, no vans have survived, so nothing was available to copy. A couple of illustrations were available based on BSA publicity material

(see July mag), but no body drawings. The Club’s library had a drawing for the rear body bearer and the rear  number  plate,   which  in   true  BSA  practice  was different to that shown on the illustrations. So, with that sparse information where to start? It does seem likely that the van would have been based on the standard 1931 trike frame, bonnet, wings and V-twin engine etc. The illustrations appear to confirm this, although the headlamps on the van were mounted on the wings as against the cross bar used for the standard trikes of the time. 1931 saw several wing styles, however the “chevron” pattern and straight lower edge bonnet appear to have been chosen for the van. See drawings of Mudwings parts 35-7956 & 35-7951 and Bonnet 35-9324. The publicity material gave several basic dimensions. Armed with this information a computer drawing was prepared, allowing the possibility of modifying the profile; the aim being to match the stated dimensions, the chassis frame and known bonnet and wing dimensions with those taken from an existing standard 1931 trike. Copies of these drawings are available from me should anyone wish to build one. It is interesting in this age of advertising standards to note that the BSA dimensions completely disregard the rear mudguard, which takes up a considerable amount of the load space. It is unlikely that one would get away with this nowadays.

Problems arose in positioning the steering wheel on the drawing; its relative position to the chassis was fixed when using standard components. However, this didn’t look right in relation to the van cab as proportioned from the illustrations. Reference to the spares part lists showed some part number differences for the van, among these were the steering column and the control rods. Having learned this, shortening the column by 1½ inches made all the difference and the drawings began to look good. Seating layout was largely fixed by the position of the rear body bearer and mudguard, although as the seat was a bucket type it could be moved back slightly when compared to the bench seat of a trike, so giving more leg room. The original vans had a driver’s seat only, the left-hand side being left free for the load. However, I decided to add a second seat for my wife Eileen. The construction details of the body had to be a matter of guesswork. The illustration of the rear of the van with the doors open showed the basic framing of the rear and gave clues as to the sizes of timber used. A study was made of similar period vans of other makes looking specifically at the roof construction, and methods used to ensure rigidity of the body in a lateral direction. The scuttle and dashboard were the most difficult as these details were not visible on the illustrations. A picture of the later four-cylinder van dashboard appears in the T9 owner’s book and this gave some clues.

After much deliberation and umpteen issues the drawings were completed using a “best guess” approach. A rolling chassis from a 1932 V-twin trike minus body was used on which to base the van. However, I had no correct wings, serviceable bonnet or bonnet surround, although examples of the latter items were available to copy. The first stage was to overhaul the chassis, transmission, engine etc. cleaning and blasting the frame and painting with black two-pack paint. Wheels were rebuilt with 19″ rims and deep dish hubs. 4.50 tyres were used although the originals had 4.00. I just prefer the slightly larger section. The only concessions to the van were, as mentioned above, to shorten the steering column and controls a little. I sawed off the lower split clamp lug on the column, bored out the remains of the tube and brazed it back onto the shortened tube. The rear spring was another spares part number change. I imagine this was strengthened to take the extra weight of the van body plus load. BSA stated the van was suitable to carry 5cwt., which I find somewhat hard to believe as the load on the rear wheel would have been considerable, and I am sure would have lead to serious instability. I have so far not been brave enough to risk more than Icwt, which seems quite enough. However, even without a load the van body is heavier than the trike, so a strengthened rear spring was deemed a necessity.

My stock box yielded a number of miscellaneous spring leaves from BSA and Austin cars, so I cobbled together a spring with one more leaf than normal which would still go into the frame tube, and resolved to see what happened. In the event, when I built the body I found that kneeling on the tail board easily bottomed the spring, so I changed the lower leaf for a thicker one, which made entry into the frame tube even more difficult, but significantly hardened the spring. Subsequent trials on the completed van showed the spring now to be too hard, and it gave a very rough ride on potholes and manhole covers, so I removed the extra leaf. I now had the standard number of leaves but with a thicker bottom one. All now seems OK although as mentioned I wouldn’t commit myself to 5 cwt. The next stage would be to reproduce the 1931 chevron pattern wings. Mudguards – Chevron pattern (see drawing in part 1, 35-7956 & 35-7951) Several mudguards of different types have been produced for the Club and for individual members by various specialists; however, I was not aware of anyone who had produced this type. A contact in the Midlands produces motor cycle guards in many patterns, and has produced the basic ribbed shape mudguard blade 35-8077 (the curved part only – excluding the inner valance), however he didn’t have a roller to produce the chevron type. I got him to make a basic D section (flat top) of the correct width and radius. I turned up rollers for my own rolling machine to add the chevron shape to these. After some hammer work to try to reproduce the rear lip as per the drawing, the basic curved section was the closest I could get to the original. The valance was bent out of steel with a wired edge added and mig welded in place. The finished result was close to original and at least it wasn’t rusty, split and rotten! Bonnet – (see drawing in part 1, 35-9324) The construction of a complete bonnet following the original integral hinge construction is rather too lengthy to detail here, however it involves lots of hammer work, and trial and error, until you finish up with the upper curved parts with fitting hinge and sides that also fit correctly. The biggest problem is the louvres, on the V- twin they are set in a raised panel which would initially have been stamped out in one swipe on a big press. I made a louvre cutting and forming tool to fit my 50-ton hydraulic press which, after some development, produced passable louvres. As my press was not large enough to swallow the complete bonnet side, the louvres were pressed into a prefabricated raised bonnet insert. The intention being to weld this, after putting the louvres, into a cut- out in the bonnet sides I had produced with hinges and wired edges etc. Initial welding by gas was a disaster as the whole side buckled badly. Nothing for it but to remake everything and to mig the inserts in next time, the theory being that much less heat input would avoid the buckling – ‘wrong’. The third set (I was getting better at producing hinges etc. by this time) were given to a professional welder with much better gear than I had, who thought he would be able to avoid the distortion – ‘wrong’. Mk 4,1 decided to soft solder the inserts in, pre-tinned them and gently flowed solder round the join. Guess what? Mk 5. Industrial Araldite – great stuff and no distortion. I wish I had tried this before, so far very successful and has survived a good deal of rough handling. Two months of my spare time but I now had a bonnet. Next problem – Radiator Surround. Most owners know that radiator surrounds are like hen’s teeth, and those that you do find are usually dented and badly cracked. There are two types, the early one having straight sides and a simple inward turn round the mesh, while the later type have a slight curve on the outside vertical edges and a rebate round the mesh. I had two examples of the early pattern. Neither of mine were good enough to use, and after a considerable time patching and silver soldering I was still not happy, so I thought I would have a go a making one from scratch. I chose 1mm half-hard brass as the material. The originals were a nickel or German silver and I didn’t know where to get any of this, anyway not being too confident, I wanted something not too expensive. At 1mm the sheet was thicker than original, but I thought this would be more forgiving in stretching and planishing, also to get a smooth finish I might have to resort to filing, and there would be more scope before rubbing through. After a couple of experiments I decided I needed a male former to shape the brass over and that I would need to produce the surround in several sections, these being silver soldered together after forming. The former was produced in MDF (medium density fibreboard) beloved by the DIY enthusiast and easily cut and sanded to shape. Several thicknesses were glued together and jig sawed to rough shape before filing and sanding to match the profile of an existing surround. Surface hardness was improved by coating with several coats of glass fibre resin. The top section was produced in two pieces with a horizontal join approximately half way up the front face, the sides and bottom sections all being single pieces. Frequent annealing was required, this was not easy due to the length of some of the pieces and necessitated the use of a large propane burner and a number of fire bricks to build a hearth. After much hammering and annealing the sections were silver soldered together before finally planishing from the inside against a heavy polished steel plate and steel dollies gave a reasonable shape. Any high spots were filed flat, and low spots tapped up with a ball hammer from inside. The internal frame for the shell is fairly straightforward, made from 0.8mm steel sheet with punched slots for the bonnet tape, this being soft soldered in place. Originally the ¼” thick mounting brackets were riveted though the shell of the surround, in my view not a good idea as this stresses the shell and is the main reason why so many crack and split. I changed the design and orientation of the bracket so that it is bolted to the steel frame of the surround, thus minimising any stress on the shell. Finally finish with wet and dry then a buff before sending for nickel plating to give a finish close to the original nickel material. I was lucky enough to have a spare mesh although I believe it is still available should you need it, this was soft soldered m place. Another month had gone by but most of the steel work is now done, I could now become a carpenter for a while. As I mentioned, no precise details of construction were available, however I started with the main long lower side sections of 3″ x 1″ ash and a 9mm marine ply floor.

The ash pieces were inset to allow the vertical frame members to be glued/screwed/bolted in place. The photos give the general idea. A close up of the angle iron cross member shows a change from the original in that short lengths of 1″ angle were welded vertically at the ends to support the main rear door posts. These are slotted to accept the angle and through bolted. The resulting assembly is very rigid, an important point in avoiding body sway. Underneath the floor run two lengths of 1″ angle iron to stiffen the floor and link the wooden cross member at the front to the rear cross piece and, importantly, the angle iron cross piece referred to earlier. The two holes used to bolt the body to the rear of the chassis are just visible on a piece of flat 1″ x ¼” length of iron welded across the longitudinal angles. Incidentally, trike bodies were mounted at the front corners and the rear cross member only. Don’t allow the floor to touch the frame centre tube or you will get increased noise and vibration. If contact is unavoidable, then try a rubber pad sandwiched in between to isolate the body. I was careful when I cut the hole in the floor for the rear wheel to allow sufficient space to pull the wheel up through the floor. I have had problems with this before and made the opening too narrow. This time I was sure I had it right! I forgot that extra clearance would be required for the deep dish hubs. I had only used shallow dish before, and once again I couldn’t get the wheel out, hence the cutaway in the angle shown in the photo. I should have offset the angle to the left a bit more. The front of the scuttle is built up in the normal way but the rear is simpler than a standard trike as it is vertical and doesn’t have the curved end bits which are quite tricky to make on a standard body. The roof cross members are quite deep and half lapped where they join the vertical ones. As the roof is curved in two directions along its centre line, the long centre support is designed to curve over the three cross members. To ease this the centre strip was laminated from four 1¼” x ¼” strips. The solid infill at the scuttle shown on some of the photos was temporary. Roof covering of period vans took a number of different forms, longitudinal strips of wood with fabric covering being quite popular. However, no strips were visible on the illustration, so I took the easy option of using 4mm ply. I did have some misgivings in that I was worried that I might not be able to persuade the ply to curve in two directions at once, however in the end this wasn’t a problem. The ply was glued and screwed all round. Leave a small overhang to fold the roof covering over and then screw a standard alloy extrusion gutter in place (available from Woolies). The rest of the details are clear from the pictures. After framing, the whole van was skinned in 4mm ply. The originals were stated to be fabric covered although I did find a reference to special finishes available to order. I had a hankering to have the van sign written to liven it up a bit, and felt that the original blue fabric might be a bit dull, so in order to get a good paint job I over skinned it with 0.8mm alloy. The roof was fabric covered. Use a high temperature contact adhesive for this, as the standard stuff will soften in the sun. Rear window frames were bent from half round alloy after re-annealing several times. The remainder of the detail half round being added in the usual way. The front windscreen surround was made from a combination of half round and angle alloy screwed in place, with the laminated glass trapped between standard 1/16″ rubber strip. The rear ovals, again in laminated glass cut and supplied by my local Al Windscreens depot, were bedded in black Seelastik. The wooden dashboard was a piece of mahogany from a redundant dressing table; this material may be a bit over the top for BSA but it looks good. The rear mudguard is basically as detailed in ‘Front Wheels’ a few months ago, it sits on a wide flange and is retained by four wing nuts. The seat frames were fabricated from steel sheet rolled to the curvature and, after adding wired edges, welded to a base frame. The covers, made from expanded vinyl on my mum’s old sewing machine, were padded with wadding and fitted over sponge rubber cushions and a 9mm ply base. The seat cushions lift out to give access to a useful storage area for tools etc. under both seats. Some of the illustrations show only one seat, as the second had not been produced when they were taken. Inside the rear are ply strips as shown in the original illustrations to avoid the load of 5cwt (!!!) from damaging the sides of the van. Rear door bolts on the left door as shown in the photo are standard hardware, the main square key operated catch having a pair of extension bolts top and bottom which give more rigidity to the doors when closed.
Electrical wiring was standard except that, learning from my mistakes, I wired many of the runs though a multi plug situated below the floor under the driver’s seat. The object being that to remove the body, as far as the electrics are concerned, all one has to do is unplug this one connector. The chassis based wiring to the dynamo, headlamps, horn etc. is separated from the body-based dash wiring and rear lights. The only exception being the starter cable to the floor mounted starter switch.
After preparation, an etch primer was sprayed followed by a couple of coats of hi-build primer and the two pack Brooklands Green top coat. My mistake was too thick an application of etch primer round the bonnet hinge, which has resulted in the paint lifting. It appears that etch primer must only be applied as a mist coat – we live and leam. I’ll have to do the bonnet again sometime. Two-pack paint is a problem health wise and proper equipment is required, however it does give a good lasting finish and is not too difficult to spray. Orange peel paint finish can be a problem, although most modern cars suffer from orange peel and we get used to it. You can flat two pack with a lot of elbow grease and remove most of the orange peel, I did as much as I could stand before inviting our local sign writer to do his bit – which is the best part of the whole thing in my view. The van, as I mentioned in the introduction does attract many comments, mostly favourable, and lots of smiles, so it was all worth it.

Mike Scott-Coomber

Total Page Visits: 3554 - Today Page Visits: 1