Windshield question

[79XS11F]

I just got back from a quick tear on my 79 11 that I have fitted a handlebar mounted windshield to. The windshield completely removed all wind baffling BUT there seems to be a strong back draft for lack of a better description. There is a fair amount of wind coming from behind me now? Almost feels like it's pushing me along. I have never used a windshield before so ....is this normal?
Other then that question the steering is A-OK with it on and it's nice to not be battling the wind when out on a ride.
Rob

[DiverRay]

That IS normal. There is a "vacuum" that develops behind the windscreen, and that is the cause of the "backdraft".
The bad part is when you are riding, and it pushes up the jacket. If you hit a thunderstorm, you WILL have water in the small of your back!

[79XS11F]

Thanks ... I'm glad it does not mean that I have it mounted at an unacceptable angle or something else wrong. This back draft does inflate my jacket and I will have to address this or risk having a cold low back on longer rides.
Rob