It depends how much you you ride. I have leg-warmers, which are fine for a fall day, specially in the mornings, and lightweight tights for when it gets a bit colder. And I just bought some windblock tights in the hope that that will enable me to extend my commuting season a little bit further into the fall. In the past I have stopped riding in mid-October, but it's still pretty comfortable out there this year, and I am dressing up a little warmer so I feel pretty good. I'd like to try to go into November this year.
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Zero gallons to the mile