I have a 1972 Bonnie with sequence number **30701.
Different number sequence - 1972 model year used the number sequence started for the 1971 model year with KE00001.
"**" is HE or HG?
As the model year starts 2/3 through the calendar this table is tricky to read isn’t it.
View attachment 53375
A lot of that table is either misleading or completely wrong:-
. It is not correct that model years always ended at the end of a month or began at the beginning of a month; as in my previous post, the last 1973 model year bikes and the first 1974 model year bikes were all built in calendar June 1973.
. Also in my previous post is that the model year could begin/end at different times for different ranges:-
.. The first 1969 model year production were T150 engines built at BSA Small Heath during calendar May 1968, complete bikes assembled at Meriden during June 1968 (all Triumph triple engines were built at Small Heath; until the Meriden sit in from September 1973, they were then trucked to Meriden for installation in cycle parts and dispatch). Small Heath began stamping date codes and five figure numbers on T150 engines during September 1968.
.. Otoh, Meriden did not first stamp date codes on twin engines until sometime in October 1968 (T120R NC00100) but the 1969 model year began there during July 1968, Meriden continued to use the separate 650 DU and 350/500 H prefixed number sequences from the 1968 model year.
. 1970 model year, Meriden continued to use the number sequence started during calendar October 1968. Small Heath did not build any triple engines before calendar April 1970 and started a new number sequence (T150T DD00101).
. 1971 model year - due to the problems fitting the 650 engine in the new oil-in-frame, 1971 model year production began with 500's in September 1970 (KE00001) while 650's with separate oil tanks continued to be built and numbered in the 1970 model year sequence until sometime in October 1970 (ND60540?). I have it in mind the first 1971 model year 650 (T120R NE?????) was also in October 1970.
. Not only did certainly Meriden's 1971 model year end during July 1971, the 1972 model year also began (HG30870 documented) but without restarting the number sequence.
. While Meriden began its 1973 model year in August 1972, Small Heath continued to build T150 engines date coded and numbered in the 1972 model year/number sequence until sometime in October 1972; otoh, the X75 Hurricane engines also built there from calendar September 1972 also have the 1973 model year H and had their own number sequence; from December 1972, Small Heath built more T150 engines, but with the 1973 model year H and using the same number sequence as the Hurricane engines ...
. 1974 model year - while begun at both Meriden and Small Heath during June
1973 (T140V GJ55101 and T150V GJ40101), production stopped at both Meriden and Small Heath shortly after the sit-in began during September 1973. Production of complete T150's resumed at Small Heath during March 1974 and continued until early November 1974; shortly after the GJ date code was reused in June 1974, Small Heath began stamping the K year letter, so the last T150 are PK45nnn.
. 1975 model year:-
.. The first T160 engine (XK00101) was built at Small Heath also in calendar November 1974 but date coded XK probably because the last T150 engines were date coded PK.
.. "April 1974" is a misprint and only for the first 1975 twin engine (DK61000, by the then new Meriden Workers Co-operative) in April 1975.
. 1976 model year - again, "July 1975" applies only to the twins; T160 continued to have the K year letter until sometime in October 1975, after which Small Heath stamped the 1976 N year letter until the last (CN07203) engine built in March 1976.