∙Matching frame & engine numbers
∙Eligible for the Banbury Run
∙Genuine collector's item
∙Sympathetically preserved

The Birmingham Small Arms company (BSA) was credited as the single biggest supplier to the World War One war effort – a serendipitous side-effect of which was its move into motorcycle production. 

As its name suggests, BSA started off as an armaments manufacturer building guns, shells and ammunition. But as the requirement for other items grew, the company’s Small Heath Works in Birmingham were asked to diversify, first into the manufacture of trolleys and bicycles and later by attaching motors to the bicycles, such as Belgian ‘Minerva’ single-stroke engines that allowed them to self-propel. From 1919, though, that evolved with a range of BSA’s own side-valve singles, which would go on to power an entire generation of ‘proper’ motorbikes, including the company’s iconic M-Series. 

BSA added its 350cc and 500cc side valve models to its range in 1923, priced at £57 and £70 respectively, the larger one featuring BSA’s three-speed countershaft gearbox. 

And that’s what we have here – a genuine 1925 BSA ‘S25’, which was the name given to the 1925 model sidevalvers. 

The bike has been restored in the past and has a number of original features, while it is also eligible to take part in the Banbury Run – an iconic event for owners of pre-1930 bikes only, comparable to the London to Brighton run for cars. 

BF 8754 was supplied new in February 1925 to a Mr C Laston, though after that it’s history is very vague – the original information is gleaned from factory build records but it does back up the fact that the bike has its original frame and engine number. 

The current owner acquired it in mostly restored condition in 2018 so he could take part in pre-vintage motorcycle events and most recently used it for the 2019 Banbury Run organised by the Vintage Motor Cycle Club. He is selling it as he wants to reduce his collection of classic vehicles ahead of imminent retirement.

There isn’t a huge amount of paperwork with the BSA, though it does have a dating certificate provided by the BSA Owners Club that backs up the originality of its matching numbers. There’s also a V5C in the current keeper’s name, along with photocopies of old books and manuals that will be a really valuable resource for the next owner when it comes to sourcing parts. It also comes with a CD-ROM parts catalogue to help the next owner identify part numbers and source replacement components.

Overall, this is a very smart bike. The distinctive green and cream ‘flat tank’ that define this era of BSA are correctly picked out, while the frame itself is in good, tidy and solid condition.

It features a wooden storage box bearing the bike’s name (Patricia), which the vendor is happy to leave on or remove depending on the buyer’s preference. It also retains its original (and wonderful) acetylene lamps front and rear, which are hinged and need to be lit with a match if you want to ride the bike at night. Headlights like candles in more ways than one, but they’re a thing of beauty in their own right…

The front tyre has perished in storage and a new block tread tyre is due for delivery, having been held up by Brexit delays. It should be in the owner’s possession by the end of the auction and can be fitted or supplied with the bike. 

Once you figure out the starting procedure (and if you’re not familiar with sidevalve BSAs it pays to write it down) the single-cylinder sidevalve unit clatters into life easily before settling to a distinctive ‘thwap-thwap-thwap’ rhythm that only a single cylinder sidevalve can replicate . The seller tells us the engine is reliable, strong and quiet with very good compression.  It is worth noting as well, that these old engines have a non circulatory oil lubrication system, or, a total loss system as they are meant to be called. Oil is splash-fed around the engine, and a slight blue haze from the exhaust suggests everything is working and being lubricated properly.

The exposed mechanics are quite mesmerising to watch, with the added benefit that you can see it’s all working as it should. The owner had to source a replacement gas-generator for the bike, which he eventually tracked down in new-old stock format at a museum in Australia!  It was still in its original box from 1920 and in "As new" condition the seller tells us. The box is still present, althought showing sings of its age, and is available should the new owner want it. 

The magneto has also recently been rewound and fully reconditioned. The rare and very desirable klaxon horn is working very well indeed, after being sourced by the owner, who paid £180 for it alone. The brand new and un-used block tread rear tyre accompanies the used front, which is identical to its rear counterpart.

Sidevalve BSAs were once the most common bikes on the roads of the UK but these days they’re few and far between, with the best examples sought after by collectors. This one’s a really tidy and sympathetically preserved example with the benefit of recent work. It’s in fine working order and is also eligible for the Banbury Run, which will add to its desirability, while matching, original frame and engine numbers give it provenance. It’s a charming thing. 

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