This one is 1988+. Serial number? In addition to the geometry, one of the reasons for the mentioned traits is the Aelle tubeset. Normally, around this size. most manufacturers transition form Columbus SL to SP, due to the extra weigh and strength of taller riders. Aelle, while a bit heavier than SP (~150g), makes for an even stiffer frame which responds even better to pedal input and rides like it is on rails when pushed hard in corners (provided you don't exceed the tyres' limits).