Last night I did 17 miles on one of the steepest paved routes we've done on our Tuesday night group rides at Ernest Debs Park. I'm pretty sure more than half the group dismounted and walked their bike part of the way. I believe it was between a 12-14% elevation grade. I even had to unlock my two lowest gears on my 11-36t cassette which I never do even on hillclimbs. Of the age 40+ and up guys we all congratulated ourselves for making it to the top! When I got to the top I literally couldn't feel my legs, my head was dizzy and felt like I was going to puke. Though I have an urge to keep riding that hill since they plan a race there next month!