Buying a Sunbeam S7 or S8

Know what you're wanting to buy - It may not be the same as what's written on the packaging.
Caveat emptor

Buying a classic motorcycle is not that much different to buying an old car, a wooden sailing boat, or even an old cottage, what you think you see is not necessarily what you will get. Nostalgia, family stories, dreams, silver screen and music legends, personal ego and a still longer list of emotions cloud a buyer's judgement. It would be a totally different world if there were no greed, one-up-man-ship or if sellers would, as the bible saying goes, "do unto others as you would have them do unto you". Most of us are very pleased to get a really good price for something we sell. I.e. much more than we would have paid ourselves.

For the best part of their lives, most old bikes (not least the Sunbeams) were unfashionable and neglected. Before and after that lengthy period of "No dad I don't want that crappy old, oily, unreliable ugly heap, I want a Honda, Kawasaki, Suzuki or Yamaha with electric start and twin discs", many British bikes were kept on the road on an unrealistically low “fix-or-bodge-it” budget.

Today, buying a classic motorcycle is a good investment, certainly having the potential for a much better return than having money in the bank and it seems to be in the ' low risk' category. Buy a classic motorcycle wisely, keep it dry and secure and in five or ten years it will have increased in real value. A motorcycle is a great conversation topic with like-minded friends and it is relatively easy and compact to store in the back of garage, or even in your study. Because of these reasons and nostalgia for a simpler way of life, the value of these bikes has steadily increased. Not many years ago you would be hard pressed to sell a roadworthy but scruffy s8 for £500. It is now getting nigh on impossible to find a roadworthy one for sale under £4,000.

Following hot on the heels of the value of the bikes themselves is the value of commonly missing, not available new, or expensive-to-refurbish parts. The eBay market for these parts is buoyant, although Sunbeam motorcycles have been broken for the value of their parts since the early 1960's.

How do these factors affect the buyer?

Firstly, prices are already high and beginning to level off. The investment potential is still there but to buy wisely is getting tougher. Never the less it is better to buy a Sunbeam because that is what you really want. Then the cost is already justified and the investment is just a happy bonus.

Secondly, if anything is missing or not of an original specification, the cost to put it right is going to be high.*

Thirdly, we are talking about motorcycles that have frequently been neglected but which, when found by the opportunist, are seen as an opportunity to buy it cheap, tart it up and sell it quickly as a rare “barn find” for a keen profit.

Even if the bike is genuine, and such things do still exist, it is around sixty years old. Humidity, blazing summer temperatures, cold winter nights and mice will have taken their toll. Grease and oil sludge will be packed hard and dry, the rings will have rusted in the aluminium pistons and nothing will come apart easily. On top of all that, it was probably put away in the first place because it was unreliable or broken. It will need a total rebuild: engine, gearbox, steering, brakes, suspension, tyres, instrumentation, electrics, fuel system, paint, chrome, rubber parts, everything. At the very least every oil seal will have hardened and need replacing.

[*Remember that there is a difference between expensive and rare. The commonly missing or damaged Sunbeam s7-deluxe and s8 parts, like the distributor, dynamo, the correct speedo, toolbox, air filter cover or the s7-deluxe wheels and cantilever saddles are not rare but they can be expensive to recondition. However, old or non-working parts do have a value because they are needed as the basis for reconditioning or exchange. If a distributor, dynamo or speedo is missing then you may have to buy one that is in poor shape before spending a considerable sum to have it refurbished, although good ones do still come up for sale occasionally. Items of tin-ware, like the tool-box, are available new as Indian imports or in the UK as fibreglass replacements.]

The early s7 (1946 -49) bikes, however, have many parts that are for all practical purposes no longer available, although they might crop up after a few years of constant and informed searching. If anything is missing then many s7 deluxe parts will fit until you can find the right one, otherwise they will have to be made, which can be expensive. Even scrap original parts are needed as a pattern to copy and reproduce.

Sunbeam S7, S7-deluxe and S8 are unusual classic motorcycles. Read a little more about that in Sunbeams - the bikes. Because of this, most bike dealers actually know very little about them. They probably won’t know the correct specification of parts, correct assembly tolerances, how to set them up correctly or even basic specifications, such as what type of oil should be used in the rear drive unit. They don't have the parts needed and there is no Haynes manual. With only 15,000 ever produced, few bikers have ever ridden one. It would appear that even many current owners don't know what a good bike should feel and perform like.

So where do you go from here? Firstly decide what you want and what you want it for.

It may be that you want to be active in the VMCC, in which case you'll most likely find these post-war model of Sunbeam are too modern. Or you may want to go on local classic bike club runs. In which case, do they like to blasting along at 60-70+ mph or are they happy to 'potter along' sunny country lanes at 40-50mph. Sunbeams are capable of faster riding but Triumph, Norton and many other sports classics are very much more nimble.

The post-war Sunbeam S7 and S8 models may be differentiated as: the early S7 1946-1949; the S7 deluxe 1949-1956/7; the S8 1949-1956/7


First S7

Last S7

First S8

First S7 Delux






Engine #





Frame #






2,104 over 2 years 3+ months (approx 77 per month)

< From DW Monro p.38 >

Frame numbers / engine numbers :
early) S7 numbers started off being matched. The first one produced had engine, cylinder head & gear box number S7 101. A vehicle might have undergone a replacement engine or gearbox, even by the factory. Reportedly, the very first S7s were exported but then recalled and were re-numbered after being modified. As can be seen from the table above, by the end of the run the frame and engine numbers had lost their matching sequence.

S7 deluxe models started with frame number S7 2501 with engine, cylinder head, & gear box numbered S8 462. However, by early April 1951 frame numbers were S7-47xx while the engine numbers (S8-59xx) had overtaken the bike's frame numbers with almost six-thousand s8 engines having already been produced.

NB, The S7 deluxe and S8 bikes used the same engine, cyl head, & gear box, so very rarely matched the bike's frame number. However, the numbers stamped into the engine, cylinder head & gearbox were generally the same.

S8 models started with frame number S8 101 with engine, cylinder head, & gearbox number S8 104. By mid-July 1953, frame numbers were a little over s8-7000 whereas the engine numbers were over eleven-and-a-half-thousand (S8-116xx).

Does it matter? matching (or non matching) frame / engine numbers of the early bikes will have an effect on values (possibly as much as 5% if the engine is an S7 prefix, but perhaps up to 20% if an S8 prefix engine & gearbox has been later fitted). Buyers do like things to be correct but in reality a replaced engine or gearbox while riding to Cape Town is as much of the bike's history as it languishing in the back corner of a garden shed. The problem is that such engine changes are rarely documented. And lost history is lost value. Buyers do like to have a documented history, the more the better. Regarding the later S7d's and the S8's, the frame and engine number rarely matched anyway, so it comes down to those numbers matching the figures documented in the original log book.

The early s7 engine, gearbox & cylinder head are each different to their s8-prefix counterpart, in a multitude (in dozens if not hundreds) of details - although they are so similar that many parts or sub-assemblies are interchangeable between the S7 and S8, with just a little modification, even though the general specification remained almost the same as that of the S7. However, the 1949 s8 engines were all new tooling so it seems that BSA/Sunbeam's management weren't that displeased with it, nor with the feedback from the motorcycle press or the dealers. The S7 mechanicals did have a few development changes through its short production span but, aside from rubber mounting of the engine & gearbox after the first batch of bikes, all others were quite minor. The exact dating of those changes are poorly documented. Indeed some 'old stock' s7 parts were used on the first S7-deluxe and S8 bikes.

It's a credit to the bike's early design and development to say that the s8 prefix mechanicals (and also the cycle parts) had almost
no changes throughout the bike's subsequent production life. An early S8 engine will happily marry up to a late S8 gearbox, and will comfortably sit in any frame, of either the S7 deluxe or S8 model. As previously said, an S8 engine and gearbox will happily fit the early S7.

In practice however a mechanic may find that a dynamo (for example) may fit one engine much better than another - but that's simply a matter of production tolerances or variations between a batch of components. The engineering specification very rarely changed.

In short, a 1949 bike (s7d or an s8) will be as good as a 1956 one, and vice-versa. There's next to nothing to choose between one model year and another. The rear light housing and the colour of the badges changing from blue to gold c.1952 is all that comes to mind.

Buying a Project

What are you looking for? What is For Sale?

It may seem obvious that if you're are looking for a Sunbeam to restore that you might look for a 'project bike'. But what is a project bike? There can be big differences in your definition and someone else's.

'Basket Case':

boxes or bins of parts that to one extent or another have been dismantled. Very rarely a complete bike set and they may or may not be parts that all belong to the same bike. They may come from two or more bikes, possibly of different model years and some parts may be off a car or tractor. Frequently a buyer may find that there are several of one part but none of the rarer more expensive-to-replace parts. Often fastenings have been lost, including those only ever used on that model, or a box of nuts and bolts may not be from this bike. They may be mixed assortment of Imperial, metric and Unified threads, none of which even fit the bike. Perhaps the chrome parts were sent off for re-plating, and never came back. The tin-ware was welded and primed but never finished being painted.

Conversely, you may find that the chroming has come back and is beautiful. The engine's machining has been done, the journals coated with grease, and there are all new OEM bearings, pistons, rings, and bearings. You may find that the the engine and gearbox have been fully rebuilt by an experienced Sunbeam mechanic and is absolutely fabulous but the frame and paintwork have been stripped back to bare metal for painting but are now covered with rust.

The fact is that you don't know what you're buying until you open those boxes. You'll need to have an extensive knowledge these bikes beforehand - just to ascertain exactly what is there and what is not. And what is available to buy and what is so rare that it's an uneconomic proposition. Take your time and, if possible, lay the parts out according to assemblies. Try to mentally fit the parts together in your mind's eye.  If a speedo or other 'expensive' or 'shiny' parts are missing then ask if they have it - it may have been taken in the house / up in the attic / back bedroom for dry storage and safe keeping. Likewise ask for any paperwork, old tax disks, insurance, or receipts, however seemingly insignificant - it's part of the bike's documented history. I recently heard of one chap who had agreed the price, paid it, loaded the cycle parts into his van, and was about to drive away - when the seller asked "don't you want the engine and gearbox? They're in the garage".

Naturally, the storage of any part determines how well it may have survived the ravages of time and summer heat, ice, condensation, humidity, a leaky shed, the kid's adventure play, or the rat's appetite. And a twin or multi-cylinder engine will always have one engine valve open - remember that in terms of moisture. Yes, the spark plugs may be in - but the carbutetter is open and so is the exhaust.

Think also that whereas perhaps a flywheel (for example) may seem OK, if a bit rusty but it's possible that the screw-threads are damaged.

'Project Bike'

a project bike may be a very similar package to the basket case but some of the assemblies are hanging together. Often the frame and suspension are together as a rolling chassis but the engine and gearbox are out and probably part dismantled. Of course there are numerous variations, from the bike's tinware being off and the wiring is scrap or missing, to pretty well any other permutation you might think of. However, because a project bike is at least partially hanging together- then it should be easier to assess what is there and as importantly what is not..

In terms of semantics ; a 'project bike' is not necessarily made up of one bike, although there may only one part or set. So you may not get three cylinder heads as might be found in a basket case but it may be that the frame is from one, the tinware from another and the engine from yet another. If it has an old log book then the bike's and the book's frame number needs to match, otherwise that document is not for the same bike and, even though the document may have come from the bike that the engine came out of, the DVLA will not recognise it. The log book must match the frame number.

Many of the s7 deluxe and s8 parts are the same. The engine, gearbox, the complete drive - right through to the rear brake & wheel hub are identical (although of course the s7-deluxe wheel rim & spokes are different). All the electrics including the dynamo and distributor, both electrical boxes, the tool box and headlamp, the handlebars & all the controls (although not the handlebar risers), along with the instrument & switches are all the same.

The point being that if you hanker for an S7-deluxe (which is rarer to find as a project and also carries a premium price) then an s7-deluxe project with its frame, saddle, forks & front brake together with wheel and mudguards, may be combined with an s8 project or parts to make one complete bike. Sometimes the maths work out in favour of doing this, especially when the doubled up parts are sold on. It's also not uncommon to see a s7-deluxe front-end and rear wheel & mudguard on an s8 frame, as an s7-deluxe lookalike. Aside from the log book and cantilevered sprung saddle of the deluxe, it's pretty well there. Some folk have even gone as far as welding cantilever saddle type lugs on to an S8 frame and fitting the spring up the frame tube.

One of the things about a basket case or project bike is that often some parts have received attention from a previous aspiring rebuilder. For example, rusty mudguards may have been welded up and repainted (very often hand painted ) or the mechanical parts may have been degreased and cleaned. So again it's easier to see what there is and the condition of those parts. The inside of something can often tell you more than the outside. For example, the inside of a cylinder head or crankcase may tell you more about the bike's previous life than polished or even broken fins and the inside of tin-ware like the mudguards often reveals signs of welding, patchwork repairs, cracks and dents that have been hidden on the outside by body filler and thick paint.

'Barn find'

a barn find may again be similar to either a 'basket case' or a 'project bike' with regard to its state of disassembly or completeness. Tt may be completely assembled but in a derelict state. What is often nice about a barn find is that it may be one bike and it may have some documented history. The family who once owned and rode it may be traceable through the address that it was found at. Conversely, because they were laid up and forgotten, the state of them or individual parts is frequently worse than that of a project or basket case.

Why are perfectly good bikes laid up and forgotten? Most commonly it is because something on it broke and the parts were either not readily available or were too expensive. A kick start bronze quadrant is typical. When a Sunbeam is kicked over with vigour then the bronze teeth of these quadrants can shear off. A Sunbeam correctly set up only requires a gentle prod to start her. Anything more and there's something wrong. The quadrant is quite an expensive item to replace but they are still available. The bike may have been laid up with the gearbox side cover off so there may be rust inside.

There are still vintage cars and motorcycles that crop up, from the estate of a deceased parent, husband, or uncle, but they are rare. If you find one, expect every item of rubber to have perished, all the oil and grease to have congealed, the piston rings to be corroded into the piston's grooves, and mice or rat damage. After 60 years you won't know what you are getting until you start to dismantle it.