Bigger screen means more pressure.
So manufacturer reduces back pressure with the opening creating a laminar flow.
If you want the benefit of larger screen, then you'll have to live with this negative during rain.
I will happily live with the negative during rain because I love this windscreen so much when it isn't raining which is probably over 95% of the time where I ride.
My understanding, correct me if I'm wrong, is that all RT windscreens allow water to come under the windscreen so it is more an RT design issue than a windscreen issue. Again, correct me if I'm wrong on this.
I'd like to hear from other riders who are using other windscreens, including stock ones, who have ridden their bikes in the rain to hear what their results are.
If I choose to ride to Alaska this summer, I will plan to potentially ride several thousand miles in rain so I'm just trying to get ready with options in case it becomes a problem, which I don't expect it will be.
My riding buddy rides an RT with the same windscreen as I have, uses a Shoei Helmet and wears glasses. While riding in the rain he has issues with his visor and glasses fogging and if he opens up the visor to vent out the fog, he gets rain on his glasses making visibility more difficult but this won't keep us from riding thousands of miles in the rain.
I would be happy to try some anti-fog samples, especially this time of year when we have rain, fog and cold temps to deal with. I'd like to try the anti fog product mentioned in an earlier post on my Shoei visor and see how it works in the rain, fog and cold.
I'm always looking to make the riding more enjoyable especially since I like to ride very long days in rain or shine. Even though I have been riding for over 42 years now, I'm still having the time of my life exploring places I've never been to.
If things work out for me this summer, I hope to ride from Central California to Nova Scotia and back and may put in many 1,000 mile days which means I don't want to have to stop riding when the weather changes and I don't want to compromise safety because of any visibility issues with my visor or windscreen. My riding buddy actually has more issues with visibility than I do so the solutions I'm looking for are for him as well.