Hi hoyc,

about the serial number for your bicycle. I would respectfully disagree that it is Merida of Taiwan. For two reasons.

First: The third character of the serial number is "M" which is supposed to indicate the month in the Merida format. The letters used by Merida went from A to L, the first 12 letters. I have only seen Merida serial numbers using these letters for the month. "M" is outside this range.

Second: The second character is the number "1", which indicates the year. Based on your description of the frame the year of manufacture is probably 1981, as opposed to 1991 or 1971. The earliest Merida serial numbers that I have seen are from 1983 and have a "-" as the third character and only 4 digits following the month character. Example: M3-E1234; where M=Merida, 3=1983, E=May, 1234=sequential number. Your serial number is different from this format. In the 1984 Merida serial numbers there begins to be a fifth digit in the sequential number. Sometime in 1987 the Merida serial numbers loose the "-".

So what manufacturers serial number is this? I think it is Miki of Sekai, Japan.

Miki serial numbers used the letter "M" in the month, they skipped the letter "I" which was not uncommon in Japanese serial numbers. Miki also used 5 digits for its sequential number.

I would decode your serial number to M=Miki, 1=1981, M=December, 55550 in the production sequence.

Miki manufactured frames for several brand names in the early 1980s, in Europe, Australia, and North America. I cannot say which brand name was on you bicycle.