This thread is timely, we have been joking about this very topic lately.....- since I grew up running/riding a bit south of Cleveland, my road riding limit is about 25. Now that I live in Richmond,VA that means I ride outside all year. This has caused varying degrees of amusement and horror among the cyclist/triathlete friends I have who all move to indoor trainers when it is below 45. Actually, the tri club rides on Saturday morning all moved inside in October (when it was sometimes 60....)