Sunbeam S7 (1947) Review: Guido’s Staff Bike

Date 29.11.2011

Presented by
  • Motorcycle Trader


1947 Sunbeam S7

Ever been tempted to jump in and buy a classic bike? Here’s a hot tip: do your research first. Of course you could do what I did, which is dig out the info and then cheerfully ignore the advice.

A few years ago I had a hankering for a Sunbeam S7. Never heard of one? That’s understandable, as they were released 64 years ago when only half-developed. Needless to say, Sunbeam S7s have never scored the legendary status accorded to two-wheeled British icons such as Vincent, Bonneville or Commando.

No, it wasn’t reputation that sucked me in, but looks. In the flesh, the S7 is a truly handsome piece of machinery. The sweeping curves sit up on balloon tyres, while the reverse hand-levers and the view across the distinctive Smiths Chronometric speedo somehow ‘do it’ for me.

Perhaps I should have taken more notice of the advice from an international owner website: “Restoration of this model is not recommended for those with shallow pockets or without considerable engineering skills.” Frankly, I have neither. Mine was a runner, so how hard could it be?

Here’s a tip when it comes to old vehicles. If it’s got wheels and an engine, it’s eventually going to be trouble – the only questions are when and how much. In this case, we’re talking about a machine over six decades old and so, while it was sold to me by a friend, in good faith, no-one should have been surprised when it decided to start shedding some alarmingly expensive parts. Before we get too deep into that, let’s have a quick history session.


Englishman John Marston set up the Sunbeam company in 1895 and produced his first car four years later. Single-cylinder motorcycles came along much later – from 1912. The machines developed a reputation for being premium kit, something which lasted until the company was bought by AMC in 1937.

AMC developed a new single, but war time work soon took over the factory’s operations. BSA bought the outfit in 1943 and, in November 1944, the company turned its attention to developing “the machine of the future”.

The company hired engineer Erling Poppe as the head designer. Though Poppe at the time was working as a bus engineer, he in fact had strong motorcycle experience, including the ill-fated Packman & Poppe Motorcycles from the 1920s. Evidently co-founder Packman died after an argument with a salesman, then the factory burned down, then the new owners got wiped out by the Great Depression. I’m guessing Poppe’s nickname wasn’t ‘Lucky’.

Sunbeam invited the public to provide ideas on the machine of the future, via a series of stories in The Motorcyclist magazine. It’s also said that Poppe originally mimicked a captured BMW boxer, but the design was rejected as being “too German”.

In any case, Poppe’s end result was radical for its day: a tandem twin with an all-alloy construction, overhead cam, massive dry clutch and shaft drive.

Some of the publicity touted it as a two-wheeled car, while it was sold as a gentleman’s tourer, priced at over £200 – a fortune for the day.

A small batch of very early models were famously sent to South Africa for police work, and were promptly sent back as the vibration was so severe as to make them unrideable. This forced a hurried design change to include rubber-mounting for the powerplant.

There were three models from 1946 to 1957: the original S7 in black, with reversed hand-levers; the S7 Deluxe in green, which internally was a complete redesign; and the S8, with slimmer wheels and guards to lighten and modernise the look.

Stewart Engineering, which bought all the original factory stock and records, has supported them with a parts service since 1960, and estimates there are no more than 200 of the original 2000 S7s left running, worldwide.

Mine, called Winston, was built in 1947 and shipped to Bennett & Wood in Sydney in 1948.


Here’s another cheerful bit of advice from the owner website: “This model [the original S7] generally commands the highest of the shaft drive Sunbeam prices mainly due to historic interest, however it also provides the least usable motorcycle of the three. Reliability although modifiable is not great… the handling is poor in comparison with either of the other models and performance was always a compromise.”

Great, so if by some miracle I get it to run long enough, it will try to kill me, but slowly. Here’s what happened.

• Ride one. It ran okay but the charging system had gone to lunch. Just made it home. Distance: 15km.

• Ride two. It was a hot summer day, the traffic was heavy for a Saturday and it stalled at the lights, in front of a huge line of cars. Tried to disassemble its own carburettor. Called for a trailer. Distance 5km.

• Ride three. Went ‘paff’ at an intersection and sulked. Called for a trailer. Distance 3km.

And so it went spiralling down, until one day it expired at the end of the driveway – at least I didn’t have to call for the trailer.

Time to bite the bullet. Initially I asked Phil Pilgrim of Melbourne’s Union Jack Motorcycles to give it a service and new tyres. The tyes turned out to be the same as fitted to Harley WLAs – so we had some sort of base point to start with.

Along the way we discovered Penrite Oil’s website to be useful – the only place that was able to recommend the correct fluid for the somewhat delicate bronze worm rear drive.

While the engine itself was sound, as time went on we discovered two major problems: the generator on the front of the powerplant was self-destructing, while the distributor had a bent shaft and was not long for this world. Not a problem, you would think. Well, the only available bits were for the later Deluxe model, which meant Winston’s components had to be hand-made.

City Auto Electrical Services in Melbourne took on the task, including a complete rewire. Jack, the owner, is a wizard at this stuff, though this job tested even his patience. One afternoon I turned up there to discover him and mechanic ‘Stripper’ staring at Winston like a couple of startled rabbits.

“I just brought it back from a test ride,” explained Stripper, “And it caught fire!”

Great – when I perused The Sunbeam Owners’ Bedside Book, I must have missed the chapter on self-immolation.

Despite the fact it tried to turn him into toast, Stripper developed an affection for the bike and suggested a few more jobs that needed doing. One of them turned out to be replacing the kickstart quadrant, also made of bronze, which I’d flogged out during one of my somewhat petulant and perhaps violent attempts to restart the monster.

There were numerous other tasks, by the end of which we were on first name terms with the good folk at Stewarts.


Guess what? You can get them to run! I dropped in at Jack’s to congratulate Stripper on his work, only to be told that Winston was his last job as a mechanic – he’d gone truck driving. So Winston was Stripper’s last job as a mechanic… what had we done to him?

The weather of course was stinking hot the day we took the photos for this story and that, combined with the constant stop-start nature of photo shoots, soon had Winston sounding like a distressed asthmatic. So here’s a tip – think about the time and place the bike was designed for and try to ride it accordingly. Evidently a machine built for English weather and 1940s traffic is never going to be happy commuting in near-40-degree temps in the Antipodes in 2010.

Other than that, and some revision of my kick-start technique (one is advised to ‘press’ the lever, not kick it to death in a lather of rage), there have been no real dramas. I’ve now succeeded in riding it somewhere, and back, under its own power, without having to open a toolbox. In fact, there’s a chance this will become a Sunday ritual.

The S7 is a peculiar thing to ride. It rolls around on the big wide tyres and, while the suspension is primitive, the ride from the sprung saddle is very comfortable. Performance is ‘stately’, thanks to a meagre 17.7kW (24hp) pushing a lump that weighs in excess of 200kg.

Its low compression engine (6.0:1) has a pleasant enough beat and is happiest when kept humming along at around 80km/h. Meanwhile the gearbox is surprisingly good for its age. The right-foot pattern is one up/three down and has a long throw, but is free of false neutrals.

Steering feels more like you’re tacking upwind than pointing a motorcycle and the brakes are atrocious by any current standard. You find yourself leaving big gaps in the traffic and having a minor panic attack any time some Wally up ahead decides to slam on the anchors.

All indications are that, with gentle use, it won’t need to see a spanner for a very long time. Which is just as well, as early on the running costs were working out to around $200 per kilometre. Which means a Sydney to Melbourne run would cost around $176,000.

I actually love riding it. When it’s humming along, it engenders thoughts of a different if not gentler era, while there’s no question that Sunbeam got the styling spot on – so much so that the Guggenheim Museum’s The Art of the Motorcycle book (which followed on from an international exhibition in 1998-2001) lists the S7 among the models that had long-term historical significance. And let’s face it, on a machine like this, you get plenty of time to think about the challenges of history.