I ride a single speed, so no need to shift. When it gets below freezing I wear silk glove liners under wool mittens under leather mittens. I can pull my thumbs out of the thumb holes and tuck them into my fist unless I'm climbing or speeding down a hill. I tried Bar Mitts, but they weren't any warmer and had the big disadvantage of allowing me only one hand position. My LBS was kind enough to take them back.