My last 10 rides I have been lucky to do 9 mph. Snow, ice, twisty paths, headwinds and studded tires plus all the stuff needed to keep warm in wind chills of 10 F. When it is warm, if lucky, might get 12mph over 20 miles. Same hills, paths and often winds, but not wearing all that clothing and regular tires help a lot. Apparently, I could feel bad about going so slow, but I don't. BTW, I find it dangerous going over 30 downhill because hitting ice, having a car pull out, getting doored or just hit by someone on their phone, drunk or unconscious can get you killed or crippled. Screw that.