I’ve spent a lot of time thinking about what would be the ultimate bike for a down-hill paved road bike would be. I honestly think I could go really fast on a 22” BMX with less twitchy geometry and geared for speed. I wish I could build a custom bike just for bombing hills. I used to kill the motor on my Yamaha at the top of descent in Rocky Mountain National Park and coast down trail ridge road. I’d hit 50mph and have to break because I’d catch up to traffic.