I bought this Sekai 4000 at a thrift store in Palm Springs, Ca. for $35.00. I am a newbie to road bikes and my original intentions were to convert it to a single speed but I think I will leave this bike stock since it seems to have almost all of the original parts. I am not sure of the year, the serial number is M1C00832. Could someone tell me a little more about this series? Thanks, GPecker- La Quinta, Ca.