dduelin
Site Supporter
The feature that makes the Madstad work so well is the 3" or so gap at the bottom. The air flow splits at the bottom of the shield and the large gap allows sufficient flow to pass behind and up the backside of the shield and smoothly reattach to the flow moving up the front of the shield. This keeps the air coming off the top and sides of the shield to remain relatively smooth and free of turbulence and vortices that make noise and buffet helmets. Most windshields have a huge area of low pressure behind them and it's very chaotic as higher pressure air from the top and sides rush around and into the low pressure trying to equalize the air pressure behind the shield. What has worked best for me, besides the Madstad shields, is the run with lower height screens and lots of rake so the turbulent air stays below my chin and my helmet is in clean air flow.What angle do you use for your Madstad,and did you play around with angles? I have tried both the 18.5 and 22" national cycle screens (one was borrowed, fortunately didn't buy both), and neither worked for my 5'10", 33" inseam self. I had terrible top of the head buzzing and booming even with the 22" screen at the top setting (which also interfered with my line of sight, constantly going back and forth from top to through). I'm wondering if the screen angle is the culprit in my instance.