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British Bikes / Re: Albion gearbox BF436 - where used?
« Last post by 33d6 on May 19, 2026, 03:55:49 AM »The numbering is actually quite simple. It just doesn't necessarily give you the information you seek.
Rule of thumb is as follows. The first letter usually broadly identifies the type of box. I'll use an imaginary Type "A" box, possibly even the second letter so you might have an "AB" box. Albion then used a batch numbering system so their boxes were numbered in batches of 999 using an alphanumeric system. The first batch would be AA 001 to AA 999. The second batch would be AB 001 to AB 999, third batch AC 001 to AC 999 and so on finally up to AZ 001 to AZ 999 whereupon they would just add another letter, now AAA and start again, AAA 001 to AAA 999 then AAB 001 to AAB 999, AAC 001 to AAC 999. Finally when they arrived at AAZ they would start again at ABA to ABZ then ACA to ACZ and on it goes.
This is more of a factory internal numbering system so they could keep track of internal production than an individual box identifier. As minor variations seem to have been carried out within each batch to suit various buyers it's not necessarily much help for outsiders to identify exactly what bike an individual box was made for. Albion knew and the original buyer knew but our chances of finding out 90 years later are slim.
I found all this out with my 1929 2 speed Excelsior Model 1. The original box was badly cracked so I found an identical replacement and restored that. When I came to fit it I found the identical top mounting arrangements were actually 1/4" further away from the centreline than the original. The primary chain alignment was 1/4" out. It was an entertaining exercise safely moving everything to suit.
Any questions?
Rule of thumb is as follows. The first letter usually broadly identifies the type of box. I'll use an imaginary Type "A" box, possibly even the second letter so you might have an "AB" box. Albion then used a batch numbering system so their boxes were numbered in batches of 999 using an alphanumeric system. The first batch would be AA 001 to AA 999. The second batch would be AB 001 to AB 999, third batch AC 001 to AC 999 and so on finally up to AZ 001 to AZ 999 whereupon they would just add another letter, now AAA and start again, AAA 001 to AAA 999 then AAB 001 to AAB 999, AAC 001 to AAC 999. Finally when they arrived at AAZ they would start again at ABA to ABZ then ACA to ACZ and on it goes.
This is more of a factory internal numbering system so they could keep track of internal production than an individual box identifier. As minor variations seem to have been carried out within each batch to suit various buyers it's not necessarily much help for outsiders to identify exactly what bike an individual box was made for. Albion knew and the original buyer knew but our chances of finding out 90 years later are slim.
I found all this out with my 1929 2 speed Excelsior Model 1. The original box was badly cracked so I found an identical replacement and restored that. When I came to fit it I found the identical top mounting arrangements were actually 1/4" further away from the centreline than the original. The primary chain alignment was 1/4" out. It was an entertaining exercise safely moving everything to suit.
Any questions?
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