California Scientific

California Scientific
1000 SW Powell Ct
Oak Grove, MO 64075

Picking and maintaining a windshield

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How to choose the best windshield height for you.

The yardstick method below gives the correct answer, including adjustments for your riding posture, handlebar height, seat height, etc. The table below is only approximate. To use the table, get a size estimate from the table using your height and pants leg length. If you're between sizes, use the larger size if you live in a colder climate, or the smaller size if you live in a warmer climate. People in Florida or Houston need somewhat shorter windshields, people in Seattle or Juneau need taller windshields. Both the yardstick method and the table are for people who want to look over the windshield. If you want to look through the windshield, add about 3" to your windshield height. Of course the quietest possible ride is when you're looking through the windshield, but only about 1% of our customers are interested in looking through a windshield.

Younger guys (under 35) typically want about an inch or two shorter windshield to get a sportier feel. Older guys (over 45) typically want a more quiet and comfortable ride and prefer about an inch taller shield.

If you want coverage for your body up to your shoulders, but your head in undisturbed full-speed air, then your windshield's top edge should visually hit the ground about 10' - 12' (3 - 4 meters) in front of the front tire contact patch.

Yardstick Method of determining windshield height

Shield Height
  1. If your stock shield is mechanically adjustable, put it in the lowest position. If your windshield is electrically adjustable, put it about 1/4 to 1/3 of the way up.
  2. Get a yard (meter) stick - free at Home Depot or most hardware stores.
  3. Park your bike on level ground. Measure 30' (9 meters) from your front wheel contact patch. Drop something on the pavement, keys, a rock, whatever.
  4. Measure 30' (nine meters) more, you're now 60' (18 meters) in front of your bike. Drop something else, wallet, ex-girlfriend, whatever.
  5. Tape the yardstick along the center of the windshield with masking tape or something, with the 20" mark visible from the rider's seat, aligned with the top of the windshield, and the stick pointing up. Now the 21" mark is 1" above the top edge of the windshield. See picture at right.
  6. Sit on your bike and look at the two things you dropped on the pavement. Try to sit with your normal riding posture. Don't cheat - if you slouch a bit when riding, slouch a bit now.
  7. You can sight along the yard stick and see how many inches up from the top of the shield you see the 30' and 60' marks. This tells you how many inches taller you would like your windshield.
  8. Your optimum windshield height is somewhere between these two heights. Lower for warmer climates, sportier feel and more air flow. Higher for colder climates / quieter riding / more wind protection. Our shields are typically made in 1.5" (4cm) increments to help you get the best height for you.

Table: Height v. Pants Inseam (Leg Length)

28" = 71cm 29" = 74cm 30" = 76cm 31" = 79cm32" = 81cm33" = 84cm34" = 86cm35" = 89cm36" = 91cm37" = 94cm38" = 96cm
5'5" = 165cmS
5'6" = 168cmS
5'7" = 170cmMS
5'8" = 173cmMS
5'9" = 175cmLMS
5'10" = 178cmLMS
5'11" = 180cmXLLMS
6' = 183cmXLLMS
6'1" = 185cmXXLXLLMS
6'2" = 188cmXXLXLLMS
6'3" = 191cmXXLXLLMS
6'4" = 193cmXXLXLLM
6'5" = 196cmXXLXLLM
6'6" = 198cmXXLXLL

If you buy a windshield from us, you can wrap it in plastic wrap a couple layers thick, then cut the plastic wrap away from the vent, then mount it. The plastic wrap will protect it from bugs, scratches when mounting, etc. If you might send the shield back for an exchange, please don't scratch it first. And, trust me, as impressive as your state's bugs are, I already have as many bugs as I need. Ride the windshield for 15 minutes or so. If you bought the wrong size, we'll trade you. Or, put some masking tape on your shield where you would like it cut, and we'll cut it to your spec. We want happy customers.

Instructions for adjusting handlebars and controls

Your bike was shipped from the factory with the handlebars detached, and your dealer assembled them. Not necessarily correctly. We have to check alignment on everything. This alignment will be done to fit the bike to you, not the windshield.

  1. First adjust your handlebars if necessary (this doesn't count if you have two separate handle bars bolted to the bike, these instructions are for traditional tube handlebars). Loosen the bolts holding your handlebars in place so that with a couple pounds of force you can rotate the bars, but they otherwise stay in place. Sit on your bike with your normal riding posture. If your bars are rotated forwards your wrists will be angled and your elbows will be forced outwards. If you bars are rotated too far back your wrists will be angled the other way and your elbows will be forced towards your ribs. Rotate the bars until your wrists are not angled and your elbows hang freely without and sideways pressure. The rising portion of the bars will most likely be angled back slightly relatively to the fork tubes. See pictures below.
    Handlebar Alignement

  2. Adjust your clutch and brake levers. Loosen the screws that hold the clutch lever to the handlebars. Sit on your bike with your normal riding posture. Extend your fingers on your left hand so that they are comfortably straight out, following the line of your hand and forearm. Rotate the clutch lever about the handlebars until it is just barely touching your fingers. Now tighten it up. Same thing for the front brake lever.

  3. Adjust your mirrors. Rotate the mirrors until they are in the center of their adjustment range. See pictures below. Then loosen the mirror stalks, and move the mirror stalks until the mirrors are roughly in the correct position. Then tighten the mirror stalks and do the final minor adjustment on the mirrors. The mirror stalks will likely be just barely fowards of parallel with the hand grips.
    Mirror Alignment

Cleaning your Windshield

We make our own cleaning fluid. When you buy a windshield from us, we give you a small spray bottle of cleaning fluid and a micro-fiber cleaning towel. Below is our "secret" washing fluid recipe, the result of testing about 25 different formulas:

If you don't want to play home chemist, go to WalMart and buy a gallon of Peak Bug Remover / RainX (green), about $3. Use this on your motorcycle and in your car. Fill up your wife's car, and tell her you did it. There's no brownie points if you don't tell her.

Makes 1 quart = 1 liter windshield washing fluid

  • 1/2 cup = 100ml ammonia (double this if you have a lot of bugs)
  • 2 cups = 400ml isopropyl (rubbing) alcohol
  • 1.5 tsp = 8ml car wash detergent (don't substitute dish soap or laundry detergent)
  • 2 cups = 500ml water

We recommend using only micro-fiber cleaning towels on your windshield.

Repairing your Windshield

Scratches in our windshields can be easily repaired with any good plastic polish. McGuire's, Plexus and Novus are three good brands. You can buy a 3 bottle kit of Novus #1, #2, and #3 on Ebay for about $10. We use #1 in house to clean and polish our windshields, and #3 to repair any small scratches that happen during the manufacturing. #2 is used to remove any tiny scratches left by the #3 process.

We use a power polisher, about $10 to $20 at Walmart,,, or most auto parts stores. A few minutes with some plastic polish and one of these will restore your old windshield to nearly new.


To repair a scratch, use a good cloth - a used diaper, or the microfiber cloth we supply is good. Rub across the scratch with #3 until the scratch is visually gone. Then rub against the #3 direction with #2 to clean up the area. Finally, use #1 to polish the windshield. If you can feel the scratch with your fingernail, it's not coming all the way out, you can just improve it. If you can't feel the scratch you should be able to remove it completely.

Modifying your Windshield

You may paint your Calsci shield with pretty much anything. Paint from the rear of the shield, and preferentially use Acrylic Enamel paint. From the front of the shield it will look fantastic. Make certain the shield is very clean and very dry. Use electrical tape to mask an edge, then protect the remainder of the shield with newspaper and masking tape.

To drill a hole in your windshield, it's best to use a slower speed drill, like a battery powered drill. Also it's best to use acrylic bits, available from You can do this with normal tools if you're very careful. Drill a small pilot hole in the center, 1/8" or 3/16" (3-4mm). With the full size bit, drill from the front of the shield just enough to make the full diameter hole on the front, but not all the way through. Now turn the shield over, support it on a piece of wood, and drill from the rear all the way through. Drilling from both sides like this minimizes the chances of chipping the shield as your bit completes the cut.

To cut away part of your shield, first cover most of the front of the shield with masking tape. You don't want to scratch your shield. Mark on the tape with a black felt tip pen where you want to cut.

Cut the shield with a band saw, jig saw, or dremel tool using a blade with 12 to 14 teeth per inch. Cut triangular pieces off the corners in preparation for rounding them. Or you can use the top piece you cut off to mark corner curves on your new top edge.

You can remove smaller sections of plastic using a sanding drum attachment on a dremel tool. Mark the shield first with a black felt tip pen and cut to your mark. You can draw directly on the plastic, then later wash off the ink with alcohol.

Sand new rounded corners and straighten your cut edge using a floor mounted belt sander with 80 to 100 grit sandpaper. If you don't have a floor mounted belt sander, you can get similar results by securing a hand held sander upside down in a vise and holding the windshield over that. Use a sharp piece of metal, like an open scissors, to scrape the sanded edge. This will give you the same edge as sanding with about 600 grit. Scrape with the scissors to break the sharp corners on the edge.

When making custom cuts, we use a band saw with a 12 tooth per inch non-ferrous metal cutting blade for a rough cut; a floor mounted belt sander with 80 grit sandpaper to finish the shape; a floor mounted belt sander with 100 grit sandpaper to break the corners and smooth the edge; palm sanders with 100, then 220 and then 320 grit sandpaper to prepare the edge for polishing; then we flame polish with a map torch, moving over the cleaned edge at about 4" per second (10 cm per second) with the hot part of the flame hitting the plastic.

Power tools we use
Band Saw
Band Saw
Jig Saw
Jig Saw
Belt Sander
Hand Held Belt Sander
Hand Held Belt Sander
Palm Sander
Palm Sander
MAP Torch
MAP Torch