Frame numbers.
Please treat these dates as a guide only. Andy Martin has kindly shared his latest extensive work on serial numbers, extending and improving the previous work of Jeremy Mortimore.
1934 onwards.
1934 to 1938 no known frame numbers
1939 to 1968 Frame Numbering System
Early frame numbers were prefixed with a letter and then four numbers. They were stamped on the left side (non-drive) rear dropout. The system applies to all production and the full range of models.
| A 1939 | F 1957-58 | L 1963 |
| B 1940-47? | G 1959 | M-N 1964/5* |
| C 1948-55? | H 1960 | P-T 1966* |
| D 1955-56 | J 1961 | U-W 1967* |
| E 1956-57 | K 1962 | Y-Z, A-C 1968* |
* 1964-1968 – This is a confusing time for frame dating. Did Worksop go to a quarterly prefix or did a boom in production mean that prefix changed after 9999 frames? Either way, many prefixes were used in a short space of time. Further research is required. Contact us if you can supply further information.
1966 – 1973 High-End Lightweight Numbering System
A new number system was introduced in 1968 for the Mass Production of bicycles. From 1966 the existing system remained for the high-end frames such as Reynolds 531, with an alphabetical character placed at the beginning of the serial number, followed by four sequential serial numbers. The characters were marked on the underside of the bottom bracket or, in the case of some track frames, on the left (non-drive) side rear dropout. Often the numbers included the additional custom order number for bespoke frames.
| 1966: S | 1970: E |
| 1967: U/W/Y | 1971: F |
| 1968: B/C | 1972: G |
| 1969: D | 1973: A/H |
Note: While this numbering scheme is a good guide, there may have been some crossover use of letters at the beginning/end of each year. For example, an F serial number may have been built into a 1972 bike, but the frame may have been built in 1971.
1968 – 1973 Mass Production Numbering System
From 1968 to 1973, two numbering systems were used.
The mass production models had simple numbers, up to seven digits, sometimes with leading zeros, stamped on the left (non-drive) rear dropout, at the top of the seat tube to the rear or under the bottom bracket. We do not have sufficient data to analyse these numbers and relate them to specific years.
1973 Onwards – Raleigh Worksop Numbering System
From late 1973 a new system was introduced, the “W” system covering Worksop builds until closure in 1981 and Nottingham lightweight unit builds from 1982 to 1990.
The numbers were in the form WP5000123 where:
W = Worksop (Carlton)
P = month of manufacture
| A = January | G = May | M = September |
| B = February | H = June | N = October |
| D = March | K = July | P = November |
| E = April | L = August | S = December |
The next digit indicates the year of manufacture; 3 for 1973, 4 for 1974, 5 for 1975, etc.
The remaining numbers were sequential. The numbers were usually stamped under the bottom bracket. Clearly, this system would lead to duplicate numbers every 10th year.
Note: the last cycles were made at Worksop in May 1981 and would thus have been WG1xxxxxx. However, Raleigh continued to use the W prefix for Nottingham-built Carltons for several more years.
Thanks to Andy Martin for his considerable contribution to the serial numbering systems