BSA B31 - Motorcycle Review

BSA was one of the largest motorcycle manufacturers in the world in the
1940s and 1950s. Originally an armaments company, (BSA = Birmingham
Small Arms), the company started to make motorcycles at the start of
the twentieth century. They built solid, dependable machines which were
fairly priced and they sold in their thousands.
The B31 was a very popular model that was introduced after World War 2.
Many examples were sold and, even today, there is a good supply of
spare parts. Many of these are newly manufactured, rather than old
stock, so it's not too difficult to keep these machines on the road.

[@berniebne8243]

As I young man I had an oil in frame A65, I was always being pulled over by the police. One day I saw an advert for a B31 plunger frame going for less than 2 weeks wages. So I thought why not. It was the best bike I ever had. I subsequently bought more B31/33s with & without sidecars. I wore a Barber jacket, an open-face helmet with ww2 goggles. I never got pulled over again. Ridden quietly it did 90 miles to the gallon & would cruise with the traffic on the motorway. It had a monoblock carb & a domed piston. It was quicker than some of the 500s. I rode a different std B31 with a light sidecar, a passenger & a dog over Hardknot & Wrynose Passes in the LakeDistrict without any problems. Happy days. Ideal for UK backroads.

[@mavericktriple9488]

My late father had a B31 years ago. He told me once that himself and my late mum was knocked off it by a car. At the time the helmet laws wasn't so Strick as they are now but both of them were wearing them and was told after the accident that was what had saved them. I think dad liked the BSA It just plodded along and got you where you wanted to go. He gave up riding in the 60s but when I was old enough I took him on the back of my bikes. He was blown away how the modern bikes had changed from when he used to ride. I'm sad my parents aren't here anymore and see what I've got as a modern bike now.

[@robwilde855]

There weren't ANY helmet laws then. Not until 1973.

[@Lanes-Explorer5733]

Thank you for a beautiful presentation of your B31. Really enjoyed it.. Lovely tourer

[@frankmarkovcijr5459]

These motorcycles are going to live forever. With good parts availablelity and people to work on them no reason that these motorcycles shouldn't see the century mark and beyond.

[@1212tomcat]

The nicest clearest bike review I have heard...total respect.

[@sgch101]

Thanks John! Hope you have found some of the other films enjoyable too.

[@rrosco11]

Thanks so much for the well sorted out video. My 54 B31 and I have great fun regularly across Oregon and down the coast to California and camping in the Sierras. After sorting out the mag, has given spectacular service these last 20 years and 40,000 miles. No wonder to me that so many were manufactured. Was a police bike from New Zealand.

[@sgch101]

Thanks for the kind comments and interesting info. about your bike. Mine sounds like yours so far as reliability is concerned. Once I had got it sorted, it just runs and runs. When used every day, such as on a camping or touring holiday, it starts on the first kick every time (more or less) - great fun to ride too. Seated here in England, Oregon and California sound quite exotic!

[@T8Hants]

I have a 1949 rigid B31, which I have had as a box of bits of thirty years, but its now on the way to being restored. Just need need to get some wheels and we will be there - thanks for the inspiration.

[@sgch101]

Hope it's on the road soon! You'll have plenty of fun with it and they're very reliable when sorted.

[@sgch101]

Glad you like it!

[@russell5090]

My new favourite channel , please post more videos ,

[@davidjames1881]

I went to the Manx this year and took my 57 B31 . My friend Jonah and me where parked up in this very spot discussing scallops and fish and chips ...

[@sgch101]

Such things need to be discussed and it's a good spot to park up! I was at the Manx with the M20 outfit, this year - always a good holiday.

[@davidjames9457]

My first bike was an M21 when we could buy one with a sidecar for a fiver in about 1970 ,Today I have progressed to a 1957 GB31 and a 79 Bonnie, Always loved Brits

[@Tonyv1951]

I thought mine was a bargain at £15!!!! I was robbed!

[@harryscat]

Brilliant video. Very inspiring

[@sgch101]

Glad you liked it. BSA A10 will probably be the next film.

[@paulallen3557]

Thanks, Sir. What a beautiful bike. Had a BSA 250 single in 1966-67 and would dearly love a 31 or 33.

[@twinphill900]

What a great video, I really enjoyed it. Don't know much about these old bikes myself. Thankyou for the informative video 👍

[@sgch101]

See if you can find an old bike to have a ride on. You may get hooked!

[@twinphill900]

@@sgch101 Im sure I would there is a certain charm to these bikes, and you portray that in your videos 👍

[@bobmurphy9380]

Nice bike Simon, sounds great,

[@sgch101]

Cheers Bob. After 14 years, I still enjoy trundling around the countryside with this bike!

[@691053]

Excellent video!

[@sgch101]

Thanks Marc, glad you enjoyed it!

[@docsen9777]

thats one helluva bike 👍👍👍

[@Lanes-Explorer5733]

Brilliant. So well presented - really interesting and informative. I've subscribed!

[@sgch101]

Many thanks. We’re busy restoring a 1953 Norton ES2 at the moment, but we’ll hopefully get a new film out in the next few months!

[@Lanes-Explorer5733]

@@sgch101 Ah well I certainly look forward to seeing that as I had a 1957 Model 50 during the 1960s which proved astonishingly reliable and was one the reasons why I chose a 350 single longstroke now I'm back on powered two wheels again.. Your ES2 will be plunger sprung no doubt. Peter

[@esper1965]

first classic bike whatever , they are fantastic timewharp truly great bikes

[@CosmikDebriis]

My B31 is 1949 but pretty much identical to yours. Major difference would be the fitting of a piston from a 750cc Triumph which brings it out to nearly 400cc and gives if a fair bit more "Oomph"

[@stevewaller9346]

Really enjoyable video.

[@sgch101]

Glad you liked it Steve!

[@Ivor62]

You mentioned the road test in 1946, in Motor-Cycling magazine. The reg number of that machine was GOB 861. You may be interested to know that I have recently bought that very machine! It's been languishing for some years in the back of a garage, but my son and I have started the restoration. I'll post a video when it is finished.

[@sgch101]

Good luck with the restoration. Hoping it goes well! It’s nice to know the bike still exists and will be back on the road.

[@Ivor62]

@@sgch101 Cheers!

[@user-mb4tt4xd7q]

This is tough and good motorcycle which Brit made.

[@footmarshian8295]

I love this bike if I ever get the money I love to buy one And I bet it’s not too heavy to push I would like a 1953 model of this bike Great video and nice sound of the bike

[@sgch101]

Hope you get one. I’m sure you’ll enjoy it.

[@frankmarkovcijr5459]

A baby Gold Star at a bargin price. Imagine a time when it had no ignition key was needed. A different world it was.

[@NefariousGooch]

I think my grandfather had one of these

[@lawxxxx9853]

A great example of the British single - what a lovely classic bike! And with the solid rear end, great rarity too?

[@sgch101]

Pleased you like the bike and film. There are a surprising number of solid rear end B31s still on the road. You'll probably be interested in our latest film about the BSA M21 and Norton 19S!

[@aloksarkar5877]

law xxxx nice restoration

[@leonardbradfield5447]

NEVER buy a solid rear bike - after a thousand miles you will be unable to walk. The feet get totally pounded.

[@frankmarkovcijr5459]

​@@leonardbradfield5447With a sprung solo seat a rigid can be surprisingly good. I have had my Triumph TR-6 with a hard tail and magneto for 40 years.

[@johnmullen1955]

nicely made informative and interesting. please if possible present reviews of other british made workhorse bikes.

[@sgch101]

+john mullen We're working on another one at the moment, John. It features two sidecar outfits with a 1940s BSA and a 1950s Norton. Hopefully it will be our best film yet! Thanks for the encouragement - We need it...

[@sgch101]

John, The latest film featuring a 1940s BSA and a 1950s Norton has just been released, if it's of any interest!

[@stevetkocz]

Hi there I’ve just got myself a 1953 B31 I was wondering where you got the luggage rack from? I want to do a bit of touring once we’re allowed out 😉

[@sgch101]

Hi Steven, I made the rack myself, but for dualseat models you can get them from: www.classicbikeracks.co.uk/product/bsa-b31-b33-a7-a10/ You’d need to check if this would fit yours. It is very handy to have a rack as you can then use the bike for all sorts of errands - even for doing the shopping!

[@lizcole9827]

Probably a daft question what are the little leavers on the handle bars is it for decompression??

[@sgch101]

The decompression lever is under the handlebar on the left. The small lever on top of the handlebar on the left is the ignition control, which is used to advance or retard the ignition. The one on the right controls the amount of air going into the carburettor i.e. it acts as the choke control.

[@sinan3643]

❤

[@royyforyou]

Hello sir you bullet have a handle lock

[@buckotte1414]

It's Adorable !

[@sgch101]

+Buck Otte It's good fun to ride!

[@buckotte1414]

I had a B33 [1948] when I was a teenager....what a beast ! Lots of fun, going to swimming lakes in Michigan two-up. Noise, aromas, bursts of acceleration---a kid's paradise toy--God watched over us also, since the hard tail would step-out sideways over bumps. BALD back tire too.

[@sgch101]

Ha, that's so true about the noise and aromas. Riding along is exciting with good tyres so it must have been terrifying with bald ones - I bet you had lots of fun. It must have looked pretty similar to this one, with the same gearbox too - amazing. With its bigger engine, the B33 must have been lovely. They were (and are) quite rare compared to the B31. Thanks for memories - they are great to hear about.

[@buckotte1414]

Here's a memory of the big single BSA's : We'd go swimming on the old bike....then try to kickstart it in barefeet ! We used to marvel that the compression could actually reverse our lightweight bodies-[teens]-and push us up a little if we didn't use the compression relief trigger. To us, so young, it was hilarious great fun.

[@MartynStubbsTBS]

I`m finding it difficult to find a grease gun to fit grease nipples on my BSA B31 1953, do you have any suggestions ? many thanks

[@sgch101]

I'd replace the nipples so that they are suitable for a modern grease gun. The thread is 1/4" CEI / BSF. The hubs use angled nipples, the centre stand, steering head and saddle (on the 1947 model) are small-headed, straight. You can get such nipples from Clarik Engineering Supplies, 2 Primrose Lane, Dunfermline Business Park, Rosyth, Scotland, KY11 2SF. Their website is at www.clarik.co.uk and search for "grease nipples 1/4" bsf". They are sold in packs of 10 (Lumatic types)

[@MartynStubbsTBS]

@@sgch101 thankyou

[@shanecrawford6023]

Simon, I’ll be retiring from the RCN soon. My kids wa t to buy me a gift for the “Captain” I’m thinking quite seriously about the the SAB31, we love in Canada so there are enough country roads for me to drive back and forth from the cottage. My question is, what’s the cruising speed in the event I want to drive on one of the queens highways. Posted speed is 120kmh. I’m looking in Suffolk for my bike.

[@sgch101]

Hi Shane, 120 km/h must have been the top speed downhill when these bikes were new, I guess. I’d say about 80 km/h is more realistic nowadays. These bikes were designed in a pre-motorway age and are great on secondary roads where there’s not too much traffic. They are quite capable of going long distances but aren’t very fast. I tend to cruise at about 80 km/h max, maybe 85 km/h in short bursts. Much of the time, 65 km/h seems very pleasant - the suspension is basic at the front and the early bikes with a rigid rear can give bouncy (but fun) ride at 80 km/h. They are totally different to a modern bike but none the worse for that! Hope this helps, Simon.

[@shanecrawford6023]

Soory, I should have been a little specific. I’m not interested in driving on highways, but I might want to jump on till next interchange. 90-100 is the slowest to go, thus I was looking at can I do this for short period.

[@sgch101]

@@shanecrawford6023 90 km/h should be achievable! A B33 (same cycle parts but 500cc engine, rather than 350cc) would give you a little more speed so it might be worth hunting out one of those.

[@shanecrawford6023]

Simon Hadden thanks for all your help, I really appreciate the feed back. Pls stay safe

[@KeverneEasonMAPP]

I have the same bike...she's called Belinda!

[@sgch101]

I bet she's good fun!

[@DimebagDiamonDarrell]

Simon Hadden Hello, I got a BSA 350cc B31 you know tell me where I can find a Electronic Ignition for my bike?

[@sgch101]

Hi, Does your B31 have 6V or 12V electrics? Does it have a magneto?

[@DimebagDiamonDarrell]

Simon Hadden I'll confirm this info and in a few moments back to answer it.

[@DimebagDiamonDarrell]

Simon Hadden Hello, man I was look bike and her haven't a magneto. And now? I can brought this electronic ignition? I see in a forum and telling me that VAPE it's better electronic ignition it's true? But I need know what fits in my bike? Thank you!

[@sgch101]

VAPE is also good but it needs a 12V electrical system and I don't think any B31 bikes had that. They were all 6V, I think. I'll check. It is possible to convert to 12V though.

[@sgch101]

Can you send me a picture of the engine, from the side of the bike. By the way, where do you live?

[@roysmith4716]

Lovely old thumper, I have the newer version a 350cc unit BSA.

[@sgch101]

Yes, they're all good fun! It's difficult to pinpoint one reason why. I must say I like the exhaust notes - peppy without being loud. We're hoping to do a film on a nice BSA unit single in the next few months.

[@roysmith4716]

Look forward to it.

[@sarcolo3829]

My dad has one he built as a 13 year old in the 60s and its bored out to 500cc might be a b32

[@stephenadams7211]

B33

[@MartynStubbsTBS]

What tyre pressure would you recommend front and rear please?

[@sgch101]

With modern tyres (and inner tubes) I use tyre pressures a little higher than when the bike was new. Typically 26 psi in the front and 28 psi in the rear.

[@MartynStubbsTBS]

@@sgch101 thankyou. Yes in the book it says 23 rear 16 front, to me seems to low , so I will adopt your presures, thanks again stay safe.

[@MartynStubbsTBS]

@@sgch101 I'm having trouble getting the right length front brake cable and clutch cables they are to long , can you recommend where to get them from please?

[@sgch101]

@@MartynStubbsTBS Hi Martyn, What year is your B31? The cables vary between the different models, and some cable sellers don't acknowledge this. They'll sell you a "B31 cable", which may not fit. Also note that your bike may have non-original levers, so take care over the required cable ends. As a start, try looking at www.draganfly.co.uk/bsa/bsa/a710--b3133--c101112--m202133/category/994-bsa-pre-unit-b-group-cables

[@MartynStubbsTBS]

@@sgch101 1953 plunger, many thanks

[@williamnethercott4364]

Was that a glimpse of Longframlington? It very like it but I was too busy ogling that beautiful BSA (envious).

[@sgch101]

Yes, filmed near Rothbury!

[@williamnethercott4364]

Its a lovely part of the world, I pass though it regularly but only on four wheels. Hence, I am enjoying your films.

[@dekipet]

Hey, you are riding in the wrong lane! ;)

[@baijnathsahukrishiudyog2777]

India me new seal ho BSA moter ciekil

[@MartynStubbsTBS]

Are spares available

[@sgch101]

Yes, most spares are easy to obtain via mail order, and some (the parts that wear out quickest) are still manufactured.

[@MartynStubbsTBS]

@@sgch101 thankyou. Is it OK to run unleaded fuel with these old motorcycles?

[@sgch101]

@@MartynStubbsTBS Yes, it's fine. Some people put some lead-replacement liquid into the tank each time they fill up but it runs fine without this. This may well slow down valve damage but these B31 engines are so lowly tuned that it probably makes little difference.

[@MartynStubbsTBS]

@@sgch101 thankyou

[@iainmackenzie6095]

Triumph

[@VCYT]

LOOKS LIKE YORKSHIRE.

[@sgch101]

It's about 100 miles north of York, in Northumberland, near Rothbury.