I think the mantra should be amended slightly to all the right gear all the time, eg thermal and waterproof in the winter and vented gear in the summer. I think being too hot and dehydrated in summer is equally as dangerous as being cold and numb in the winter. I ride all year round but mostly for pleasure as I don't need to travel to work so more miles in summer but still riding every month in winter. This last year I've also been a volunteer rider for a blood bike group which means I have to go out when there's a call irrespective of weather; the service is overnight and at weekends so it's been good for maintaining poor weather riding skills!
