B31 & small BSA bikes

[Bikergrandad]

 Hi to all.
 Muskrat I have had two A7 Combination but that was 40 yeays ago.
   Thank you for letting us have a site for B31 and smaller BSA bikes.
    So send in your photos of our bike or bikes and a write up.
    I just sold my BSA C12 1957, but this is my bike now B31 1954, it needs some work on it.
    Magneto Rewound, Seals, a lot of the bike will be sprayed and a Complete Service.
    Thank you BOB.

[muskrat]

G'day Bob, nice work mate.
A lot of the cycle and electrical parts on the B's are the same as A's.
I love the sound of a single. I heard one go past a few weeks ago. I heard him wind all the way down to the lake a good 3 miles and could tell which bend or dip he was at by the tone.
Cheers

[Greybeard]

I love the sound of a single.

Yes, me too. If I were to consider selling my A10 I would like a good old single cylinder plodder. I think a single would suit my riding style these days.

[scotty]

here's my '54 B33 single

great fun to ride

S

[muskrat]

Good one. Looks like someone tried to ride a HD over the bridge!!
Cheers

[Brian]

Nice one Scotty. Here's a pic of my '55 B33.

Also my '47 B31 and '49 plunger B33.

[muskrat]

I'VE CREATED A MONSTER

[Brian]

Best not mention the M series then.   

[Topdad]

Really nice pictures , yeah could live with a 500 single ... if I didn't have a A10 , BobH

[Beezageezauk]

I share my riding between my A10's and my faithful B31.

Owned since 1974 the old girl has taken me to almost every country in Western Europe and until about 10 years ago she was often seen two up with full camping equipment.  "The Cup", as she is affectionately known, is still used regularly for long distance trips and isn't that much slower than the A10 Golden Flash.  In comparison she's lacking a bit in acceleration but considering that it's only just over half the engine capacity it does pretty damn good.




Beezageezauk

[KiwiGF]

this is my b31, it will end up as a rigid special with 390cc, yamaha piston,  389 carb and goldie touring cams

Ive ridden my a10  a fair bit in the company of a plunger b31 with similar engine spec and the b31 keeps up easily (dammit) 

[wilko]

Why a Yamaha piston. The usual overbore is with a T140 piston which are cheap as chips on ebay a pair? If you seize one you have a spare, all for 150 bucks!

[KiwiGF]

hi wilko, the project bike came with the xs650 piston and the cylinder has already been bored to match, its been looked at by a local "expert" and there are pros and cons, the yamaha piston is lighter with a shorter skirt and has nice narrow rings, but it has valve cut outs in the wrong place, it looks like it wont need a spacer under the barrel to reduce the compression unlike the triumph piston. Its oem yamaha so hopefully of known good quality.

Its worth a go I think, and as its slightly smaller diameter than the triumph piston the barrel can be rebored later to suit the triumph piston if it doesnt work out.

[Butch (cb)]

I had a '50 plunger B31 some years back, it seemed very slow. With hindsight I suspect I was just treating it too gently. I sold that one - somewhat regrettably now.

My only other BSA is a Bantam. I'm not keen on these - but it was my wife's first bike and a project for this Winter. I've found some lightweight girders to put on the front and will be bolting a rigid rear triangle on. Adding lightness and going for a kind of board tracker look.

[Bikergrandad]

 Hi to all.  Come on lets see some of your smaller bikes. This is one of mine.
               BSA Bantam 125cc D1 1953 it was a wreck I hope the photos come out ok. Bob.