I can make these three glove items work for any conditions under 40 degrees F all the way down to below zero:

1. Pearl Izumi Cyclone Gloves - Not a very warm glove, but good padding and fit very snugly. You could change a tube without taking these off.

2. X-tra Large pair of REI Fleece convertible mittens with leather palms. With these over the Cyclones, I'm good down to about 20 degrees. I think the amount of air space inside them is what makes them work so well. You can also flip open the mitten part if your fingers are getting two warm. You can also leave your pinky and ring finger in and the other two out, etc.

3. X-tra Large pair of Outdoor Research Gore-tex Shell Mittens. These fit perfectly over the REI mittens and really seal the deal, litterally. They have cinch straps at the wrist and just below the elbow. Batten these down and neither wind nor water is getting in, but water vapor can always find it's way out. One day last winter at about 15 degrees F my fingers were freezing with just the first two layers. I stopped and put the Shell mitts on and was amazed at how my hands warmed up instantly.

These 3 layers are perfect at 0 degrees F and perfect in a 33 degree downpour. I use very small Shimano Rapidfire MTB brifters (1994 XT) in the winter and even mittened up with all three layers it's very easy to shift and brake and hang on.