Most of the mountain bikes I've come across aren't as upright as hybrids or beach cruisers. Road/cross/gravel bikes seem to be more aggressive. Search for "bike fork stem extender" online and maybe that'll help with a new bike you choose. Also you can get a shorter stem if available. I personally ride a Santa Cruz Tallboy Carbon and find it very plush for fire roads and nothing too rough. On the road, it's not as fast as a road bike but super comfortable. Mine weighs 25-26lbs complete with pedals.