Rear Derailleur Freeze?
On my commute in yesterday (-35 C, -30 F), had a problem with my rear derailleur. I'm using Shimano Altus rapid fire. When I tried to go to a lower gear, it felt like there was no resistance whatsoever on the shifter. Early on in the ride, I found that if I kept pumping the shifter, eventually, it'd click and shift gears. By the end of the ride (about 40 min in), the shifter wouldn't catch.
Is this likely a frozen cable, or is it likely to be something internal within the shifter itself? Is it just a case of putting some lube on the cables?