Quite a few people have asked me about the windshield I have installed on my Duke 390. They all want to know how effective it is in reducing the wind blast at high speeds.
The short answer is no, its not effective at all. And I seriously doubt any windshield being sold in the market will be effective on the Duke. If you know if any please let me know. The windshield on my Duke is merely a cosmetic part, that’s all.
Here is the thing. The most important dimension of a windshield is not its height. Rather its the distance from the rider. People think taller the windshield, greater is its chance of deflecting wind over the helmet. But if you look at it closely, further the windshield from the rider, greater is its chance of doing it’s job.
Air hits the windshield and is deflected upwards and sideways. But the deflection happens over a distance. So more the distance, more the deflection. My point is a shorter windshield placed further from the rider may be equally or more effective than a taller windshield placed close to the rider.
The windshields on big, tall and long adventure bikes are far more effective than those on small and short bikes because they are place way in front of the rider. Check out these pics.
If you notice, sitting upright I can’t reach the tip of the windshield with my hand unless I lean forward. However, in case of shorter bikes like the Duke I don’t even need to extend my hand all the way to touch the tip of the windshield.
In the case of adventure motorcycles the air has a decent amount of distance to rise above the helmet. But at very high speeds even this distance falls short and the helmet begins to rattle. That’s when specialist touring windshields like those made by Madstad can come in handy.
The stock windshield of my Tiger did a decent job till 100 kmph. But beyond that I experienced helmet rattle which impaired my vision as well as concentration, apart from giving me a headache. Triumph sells a taller windshield and I replaced the stock one with it. This newer windshield does a good job till around 120 kmph, which works for me because I rarely ride above that speed on Indian roads.