Originally Posted by Hummer

The "M" is an indicator of when in the year the bike was made. The second letters start at "A" and go to "Z". From the Giant serial numbers of this format that I have seen, "M" usually is the beginning of the next model years production. When in the year that is I do not know, but some time in the second half of the year.




Here is a link to a 1987 catalog.

http://www.stevevance.net/nishiki/im...le_catalog.pdf


In the 1987 model line up the Sport is above the Century and Rally, and below the Olympic 12 and Custom Sport.

I don't know the original prices, but I have seen a 1987 catalog with 259.95 written on the page of the Sport model. This may have been the MSRP or an LBS price.