I only wish that bicycling were as fun to me as climbing! I am not a natural on a bike. It has taken me four years to feel comfortable enough to average 12 mph and not apply my breaks at every downhill. I am beginning to actually have fun and peddel to go faster down hills. Two hours is all my body can tolerate. Feet and butt limit me. Funny thing is that the bicycle hurts my Morton's neuroma more than walking. And I will never get used to the sore butt. My poor husband has changed my bike seat numerous times to no avail.