I ask the question whilst sat outside a cycling cafe. £3 for a cup of tea BTW, home now, I was thinking about this the other day whilst out and it's came to me again today. 2° but dry. Feet, hands and ears warm all good.
Now, I've found doing the same route that basically, if I use a higher gear, my legs get tired, if I use a lower gear they don't so much. So I'm reckoning, keep them pedals spinning.
