I have recently purchased a B33 which is described in the logbook as being first registered in August 1958. It has a magdyno not an alternator, I thought the magneto models ceased in '57? Also I thought that following the Ariel full width hubs the next progression was full width Triumph type hubs whereas mine has a a single sided unit with 6 largish holes on the inside through which the internals of the brake may be clearly observed. It has no choke either, although it starts every time. It also has the larger type chain. Whereas I am very pleased with this machine I am curious about the points raised. I know very little about the various developements reference the B series machines despite owning a B31 both as youngster and again when not a youngster. The B31 is a '56. Can anyone throw any light on these apparent irregularities?
The 1956/57 B31 and B33 had frame numbers prefixed EB31. B31 engines prefixed BB31 and B33 engine prefixed BB33.
The 1958/59 models had frames prefixed FB31. The alternator B31 and 33 engines were prefixed GB31 nad GB33 repsctively.
Dont be suprised if parts have been changed over the past 59 years.
That 8 inch single sided brake is a much better brake than the 7 inch full width iron hub used 1958/59.
Thank you for your response Julian, I thought the brake good, although I was comparing it to my B31 which has the Ariel hubs and as a method of retardation can only be described as pathetic, although, strangely, the B31 rear brake is very effective (fortunately). The log book states that the engine No commences XB33, but to my astonishment the frame No commences FB31,which I assume translates as originally a 350 frame.
XB33 prefix engines were fitted to bikes in 1947. But always check the numbers on the bike. Log books dont always have the correct details recorded.
Both B31 and 33 were fitted into FB31 frames from late 1957 till August 1959. FB33 was not used.
Good grief... 1947!
I wouldn't worry too much, DVLA records are often fulll of typos..
As far as I know alternator bikes were much rarer than the usual magdynos, even up to the end of production. I suspect alternator bikes were made for "special" customers, military, police and the like...
As you say 1958 bikes usually had the Ariel type brake hubs, unless it was very late in which case the full-width type as fitted to the A10 would have been used. I had a 1962 A10 with these a few years ago and now have a 1954 B33 with the 8" brake which is much better than the A10 item, so look upon yours as an improvement. If it has holes in the back it's a Gold Star type so even better... What hub do you have at the back??
Mine has a choke, never use it, just "tickle" the carb and kick.....
The B33 is a lovely bike, less common than the B31 , enjoy it....
Cheers,
Adrian
Bristol UK