Tear offs are an essential part of your gear offering greater visibility on sticky, wet dirt tracks, and also providing a bit of protection to your delicate polycarbonate shield. Although many manufacturers offer shields with pre-installed post, most do not. which brings us to the task of installing our own. I'm going to walk you through, step by step, and show you how to easily install your own without ruining you expensive shield. Simple and easy, with just a few simple tools.
WHAT YOU'LL NEED:
- Tear off posts.
- One tear off.
- Masking tape.
- A pencil or a Sharpie.
- Some sort of tape measure (a dressmakers tape works great).
- A drill (cordless works best).
- A drill bit.
- Small Phillips screwdriver.
BEFORE WE BEGIN:
Although this is fairly simple, there are a couple of key points to note. The object here is to center your tear offs in your field of vision, not on the shield. You'll also want to be sure that your tear off posts don't obstruct your peripheral vision. Sure, you'll still be able to see, but at 100 miles per hour, both are annoying distractions when you need all of your attention on the track. Lastly, you don't want to trash that new $$$ shield, that always hurts. That said, let's begin!
STEP ONE: CHOOSING THE RIGHT TEAR OFF...
With your tape measure, check the distance across the shield, seal to seal. You'll want your tear off posts to be mounted about 1/2" to 1" from the seal. This will help with your tear off selection. Major brands (Arai, Shoei, Etc.) are all standard, so selection is simple. For other brands, note your measurement and select a tear off with a center distance close to where you want your posts to mount.
STEP TWO: ALIGN A TEAR OFF ON YOUR SHEILD.
Position a tear off on your sheild, and hold it in place with one or two pieces of masking tape* at the top. Like a hinge. Try to make it as straight and centered as possible. Next, try the helmet on. If you can, sit on your bike in a your usual racing positions. Make sure the upper and lower edges of your tearoff aren't in your field of vision. If it is, reposition your tear off, and check it again. When you're happy with it, and your tear off is fairly level and centered on the shield, proceed to the next step.
*TIP: You can make your tape a little less tacky by sticking it to a piece of clothing.
STEP THREE: MARK THE HOLES
With your tear off in place on the sheild, lift the tear off up slightly, and place a piece of tape directly under each hole. Be sure the tear off is sitting flat (no ripples) and trace each hole with your pencil. Find center line of the circle by marking a straight line vertically and horizontally through the center of the circle.
Tear off posts have an offset mounting hole, which allows you to loosen them to load the tear offs, then tighten them when you're ready to ride. Now you're ready to mark your offset point to drill. On your center line marks, simply place a dot on the vertical line, half way between center line and the top of the circle. This is where you will drill your mounting hole.
STEP FOUR: DRILL THE HOLE
Before you start, a note of caution. Polycarbonates (as with most plastics) are a very "grabby" material. An aggressive drill with a sharp angle will tend to grab, and try to screw itself through the material possible cracking your sheild, or ramming your drill through the front. The soloution is to scrape it rather than cut it. Try to select a drill with a slightly flat attack angle, or grind one flat here. Or a very tiny Forstner bit. Otherwise, use a light hand when drilling and be prepared for the "grab" at the breakthrough point.
With your helmet held securely, tear off in place, tape marked with drill position, place your drill on your mark and start your hole slowly. Avoid skating your drill (the tape helps). Finish your hole, and remove any burrs by scraping. Repeat on the next hole.
STEP FIVE: MOUNT THE POSTS
You're almost finished! Remove the tape and tearoffs from previous steps, and blow out any chips lfrom the inside of the helmet left over from drilling. To mount your posts simply insert the mounting screws from the inside of the shield and start in each post. Tighten until snug, but not tight. They should be easily movable with your fingers. Be sure the posts hang downward on the shield.
Next, try a tearoff. Move the posts slightly inward, towards the center of the shield (they should be just snug) and install a tearoff. Remember, we throttle with our right hand, so the tab goes on our left side. Secure the tear off by moving the posts outward until the tear off sits flat. Make sure it's fairly centered. Try on the helmet, and adjust the position if necessary. When your satisfied with the position and fit of the tear offs, tighten one post, and leave the other tight, yet movable with a little force from your fingers.
Lastly, clean any tape residue off of your shield, load your tear offs, and you're ready to ride!
- Move your one snug post inward
- Load a tearoff.
- Fold the pull tab over, and put the hole in the tab on the post.
- Load the next tear off - repeat step 3.
- When you have enough tear offs mounted, leave the last tab out. Tighten them by moving the tab outward, so they sit flat.