Modern day usability of big singles

[sergeantpluck]

Having had several BSA big singles as a youngster in the late 60's (even being a BSAOC branch treasurer for a while!) I am now thinking of getting one again. I have two questions which I hope someone may be able to help with:

1. What is spares availability like for a) M20  and b)B31/33?
2. Do you think they are usable in modern conditions?

If I needed "ordinary" spares (eg clutch plates, brake shoes, points) would I be able to get them within a week of so?

Lots of machines for sale are described as having been "in a collection".
Are they not ridden because it's not practical - ie maybe brakes aren't up to it or something?

Thanks for your help

(picture attached of my ex-WD M20 in about 1970. Don't suppose anyone knows where this actual machine is now do they?)

[MICKREEVES]

I ride  1964 C15.
Spares and parts are obtainable. Try ebay ,but there are several suppliers of new parts.
Mick

[Love British single cylinder]

Hi,  I ride a B44 trouble free and is very capable of keeping up with modern day traffic.
It has electronic ignition and is very reliable. Never had to buy spares for it but my other BSA's that i am rebuilding C11 1946 model i get parts from C and D autos , order Monday get them before Thursday.
Rob.

[sergeantpluck]

Thanks Mickreeves and Love British single cylinder.

Anybody got any comments on M20 or B31/33?

[David Wheeler]

Brakes are the big issue, I've got a c12 and a b31 and am lucky to not have to contend with urban traffic, both are poor but even if they were at 100% efficiency they are not up to modern traffic without being lucky or extremely defensive

[berniej]

Evening Sarge,

I guess it depends on what type of riding you're planning. I use my old thumpers quite happily in rural areas where traffic is light and, if I find I'm causing a jam, I can pull over easily. I wouldn't use it on a fast, urban road though as modern car drivers are not used to encountering old plodders and I would feel the risk to both my safety and enjoyment too great.

Spares availability is good, particularly for engine parts. Some tinware is hard to source although Indian-made alternatives are available but quality and accuracy of reproduction are variable.

One of my bikes is an M21/B31 hybrid  - the sporty B31 frame allows the 15 h.p. of the '49 M21 engine to really show what it can do 

M20s are certainly increasing in value, especially the WD models. The others can still occasionally be found for reasonable prices especially as projects.

If you go for a unit single like the B40/44/50 then I think you'd be riding something a lot closer to a modest modern road bike in terms of performance and - hopefully - reliability.

Cheers,
Bernie

[sergeantpluck]

Thanks David & Bernie

I would mainly be riding country lanes, so hopefully will be OK.

M21/B33 hybrid is certainly the type of thing that would suit me!
(Don't want to go unit construction)

[STAR TWIN]

I have a swinging arm B31. It's fine for anything but do avoid motorways. In fact, if I have a long trip as in a few hundred miles, it's my bike of choice. There's something rather wonderful about blatting gently along at 50 mph enjoying the scenery. So much nicer than mixing it on a motorway on something faster and journey time isn't that much different.
Brakes aren't wonderful, but a bit of anticipation makes all the difference. One of my riding games is to see if I can complete a journey without stopping or using the brakes. Good practice riding for my clutchless 1913 Douglas! 

[Richard Mills]

I have a swinging arm B33 and use it on all roads except motorways. Keeps up with most traffic at up to 60mph; will go above that speed but it feels to cruel except for short bursts when overtaking. Like to go out for rides of 150 miles or so on country roads and over the North York Moors; tackles 1 in 4 hills OK both up and down.
Brakes are the problem with all the old bikes because modern cars can stop so quickly. I had the shoes relined by Saftek at Cleckheaton with their soft material, and use a front brake lever with a 7/8" pivot distance, and find the brakes quite reasonable as long as I remember to leave a good distance from the vehicle ahead.
Overall, I love a day out on it and ride as far as the seat allows, that's what I find to be the limiting factor on old bikes!

[sergeantpluck]

I'm encouraged that two different riders report trips of "150 miles" and/or "a few hundred miles"!

[MICKREEVES]

I ride a C15 SS.
I see no reason why these old bikes should not be very reliable, as they were 'in the day',
provided they are in good order to start with.
I ride it mostly flat out  when out of the speed limit .(March town is only about a mile wide.)
No brakedowns yet, though I have lost the odd bit falling of. Silencer, Tool set, three times!
Mick

[MICKREEVES]

The brakes should be OK on an old bike.
My 1954 C15  has good brakes. I can easily lock the back wheel.
The front brake will get near to locking if I put in on hard. I would not do that in the wet.
Mick

[sergeantpluck]

Thanks for all the replies.
I have taken the plunge and bought a 1955 B31.
Coming tomorrow (snow permitting)
Exciting!

[berniej]

Well done! Is it a plunger model? And is it ready for the road or a project? Do post some pics when it arrives and let us know what you're planning for it.

I was hoping to get my newly built M21 combo on the road for the first time this week but, at the risk of being accused of being a fair-weather rider it's not great out there for learning to ride with an extra wheel!

Hope you have a lot of fun with it - guessing you're in UK?

Cheers,
Bernie

[Dean Southall]

I find the M20 easy to ride and kick over. Can eb a bugger to start when warm but you will get the technigue. The gearbox does have more neutrals than most bikes! Brakes are fine for the speed you'll be doing. Convert to 12v and you can have good lighting and run other items (I'm just about to fit the wiring for sat nav and a usb charging point for phone.).
Just remember that top speed is 50 ish.

Spares are very readily availbale from several suppliers and NOS parts are still being found in large quantities!