>>1635702If you're pedalling hard enough on a road bike, the action of pedalling will have you maybe even pulling up on the handlebars, regardless of how low they are. So none of your upper body will be bearing down on the bars or on itself.
Your legs, when putting in effort, will act as shock absorbers, and very little of your weight will be on the saddle.
That's the key to being comfortable on a road bike. Actually riding it with atleast moderate effort. Don't coast. Don't slack off. You won't have the power, endurance, or form/muscle memory to do this effectively for quite a long time. So keep at it. Ride lots of hills.
It's the difference between your bikes. One is comfy for cruising, one is comfy for riding.