You may remember a Discovery Channel program entitled "The Science of Lance Armstrong", detailing his preparation for the Tour De France. One segment focused on Armstrong's lead mechanic--Julien Devries, a Belgian well known in pro cycling circles. Devries had a practice of aging all of Lance's tubular tires in a root cellar. Many dismissed this practice as a waste of time; nevertheless, Armstrong, known for turning over ever stone in search of that final edge, made sure all his race tires came from "the cellar'!
Though not really effective for vulcanized tubular tires (Vulcanized tires use high heat to melt the tire tread onto the casing). If the treads are vulcanized, the rubber compound is most likely high in sulfur content, which does not really cure. Consequently, there is no improvement from storage, and these tires are best used as soon as possible.
However, more expensive tubulars are constructed in a different manner--the treads are not vulcanized to the casing; instead, the treads are hand glued to the tire casing. The high grade rubber compounds found in these tubulars do improve with age, and as the rubber dries out a bit (cures), it doesn't reduce the suppleness meaningfully, but does dramatically improve the cut and puncture resistance of the tire, which in turn, increases tire life.
The trick to aging is to remove the tire from manufacturer's packing box, inflate to approximately half the rated capacity and let hang in a dark, climate controlled environment (think wine cellar) for at least 60 days. Don't have time for all this? Not a problem--all non vulcanized tubular tires sold at Branford Bike have been pre-aged in this manner for at least 60 days. All you have to do after ordering is mount and enjoy--happy riding!