The symbols to the left of the BB cover (“technical”) are divided into 3 categories:
- A letter denoting the EMC employee responsible for the final “smoothing” of the frame before painting (A,B,F,G,M,P,T,D,Y,L,N,J,S,H,K, unusual 0, ^)
- A number indicating the length of the seat tube in cm measured c-c (for example 2 means 52 or 62, 8 means 48 or 58)
- Letters indicating tube type, geometry or model:
R = Reynolds 531
C = Corsa
X = SLX/SPX
CX = Criterium
TT = TSX
M = Strada (Matrix/Cromor)
TTB = Century TSX
XB = Corsa Extra SLX century geo
WW = Strada since 1992
The symbols to the right of the BB cover (“statistical”) form a serial number, it consists of a letter and a set of digits. A letter means another series of frames, a number is another frame in the series (001-9999). The exception is the production from 1980 (there is no letter, and in the prototypes even digits, and there are just over 1000 of them).
E – 1981-1984
Z – 1984-1986
A – 1986-1988
B – 1988-1990
C – 1990-1991
D – 1992-1993
F – 1994-1995
G – 1996-1998
H – 1998-2000
J – 2001-2002
K – 2002-2004
L – 2004-2006
P – 2006-2008
In addition to such markings, there are unusual ones:
CS – Capri Sonne
ED – Europ Decor
W – Winning ?
KE – Kelme
HL186P – Hans Lubberding 1986 Pista (Panasonic) and similar – his teammates
Model Weight Chart
References:
https://www.retrobike.co.uk/threads/eddy-merckx-decoding-for-everyone.410031/
Hernan Vivani's Blog 