Originally Posted by bostontrevor
Does your butt want to scoot back or are you fighting against sliding down? If taking your hands off the bars mean you slide forward then you need to raise the nose of your saddle so that it's level or even just ever so slightly tilted back.
No, my butt really wants to scoot back--I get a good grip on the handlebars, bend my elbows, lift my head, and then, in order to stretch out and straighten my back, I have to push my ass way beyond the rear of the seat. This has happened on my same-sized road frame, as well. Both bikes have very short quill stems--they could definitely be a bit longer. And when I look down at the front axle, it does seem awkward that my handlebars don't project further forward.
I would have bought bigger frames originally, but I've been buying used, and it seems like the sizes most in demand are 55/56/57 cm /22 inches. Maybe I'm just a little too tall for a 21 inch frame.
But first, I'm going to try Jim's suggestion about finding my COG. That sounds good. I just have to go find a friend to hold me up...