If you have to force it, chances are you’re doing something wrong.
Windshield Fitment
If you’re purchasing an OEM or manufacturer designed and built optional windshield, then as long as you buy the right model for your particular bike, the fit should be perfect with no issues.
This is, of course, as long as your bike is stock. If, however, you or a previous owner has made modifications to the bike, such as different handlebars or headlight configurations, then maybe the windshield you purchase will not fit properly if at all.
The same applies to some extent to universally fitting windshields. Although generally more forgiving, they are still, for the most part, designed around stock specifications for the machines they are built to fit.
If the machines are not stock, even a universal-fit windshield may not fit your machine—despite what it says on the box.
Bars and Lights
Pay special attention to your headlight and handlebars when looking at windshield fitment. All windshields fit in close proximity to the headlight and most windshields also bolt in some way to the bars.
Around the headlight, look for any visible wiring that may get in the way of proper fitment or may become a potential rubbing and therefore premature wear risk.
On the bars, ensure that fitment will not be compromised by any controls. And make sure that the steering is not compromised as well. Be aware that some windshield fitments require holes being drilled into the bars, so if you’re not comfortable with this idea, stay away from these windshields.
Installation
The keys for an easy hassle-free installation are to prepare well and take your time. Windshields usually come with detailed mounting instructions. Make sure you assemble the correct tools called for in the installation instructions.
Installing a windshield is generally a fairly simple task that can be easily accomplished by the home or weekend mechanic.
Follow the instructions carefully and don’t jump ahead. Usually, unless specified in the instructions, you shouldn’t have to force any components. If you do find you are forcing parts to fit, chances are you are doing something wrong.
Stop, take a break and review what you have done so far. Try to establish where you have gone wrong, put that right and then carry on.
Once the windshield is installed securely, double check that the height is correct (especially important if installing a full-size windshield) and take your bike out for a test ride to enjoy the wind in your hair (not so much any longer).