by Michael Ready, December 2005

Introduction: why I made my own windshield

Several conspiring events motivated me to create my own custom windshield: Honda’s inability to deliver me their optional windshield after more than a month, and dissatisfaction with small windshield such as JC Whitney’s to provide satisfactory protection against the cold air.

I looked at several other windshields, including the Vespa, thinking I could adapt it to the Metro. However, after, some searching, I decided (or rather assumed and hoped) I could build a custom windshield to meet my needs. I succeeded and want to pass along my lessons.

The windshield met my highest expectations.

Prior to having the windshield:

• I only heard the whooshing of the wind past my ears and never heard the engine

• I always felt the wind in my face and on my chest

• I always felt the rush of wind on my hands and up my sleeves

After installation of my windshield:

• I never hear the wind rushing past my helmet or ears. I hear the engine clearly and hear other road noise such as other cars, trucks and emergency vehicles

• I never feel the wind in my face or chest

• I never feel the rush of wind up my sleeves and my hands stay warm

• I found no degradation in scooter performance

This picture shows the windshield from the front — its really hard to photograph. (click on image for a closeup in a new window)

This picture show a close up of the part of the windshield that protects the hands. It could be a little more shaped around the blinker. I might have also extended the windshield a little lower to the front fairing if I were to build it again. Its surprising how much air comes in under the blinker arm. (click on image for a closeup in a new window)

I chose not to trim the windshield with chrome trip (my original plan) because it would be right in my sight line.

The windshield materials cost about $40 - $45 and most of a day to work out and put together. Hopefully, it will cost you less and take less time to put together.

You are free to copy the windshield for your own personal use or produce it for sale. I relinquish all rights.

The design will also work for other scooters but you’ll likely have to change the size, shape, and mounting.

Some design parameters:

The top of the windshields should be just below your eyes. This design deflects the wind over the helmet and allows you to see even if the windshield is dirty or covered with moisture. The presented design was suitable to me: I’m 5′10″. Perhaps more importantly, the top of my head is 43 inches above the seat when I’m sitting on the scooter. This provided for a 24″ high windshield as I designed it. You should adjust this measurement for optimal performance — more on this below.

The windshield width should be chosen to be about 2 inches shorter than the handlebar width. I made my windshield 26″ wide (when laid out flat). My hands don’t feel the wind but I could have easily gone wider. If I were to build a second windshield, I’d make it 27.5″ or 28″ wide.

Design considerations:

The windshield is made with 1/8th inch thick Lexan. I am amazed at how solid yet flexible this stuff is. I could almost bend it in half with a 4 inch radius without breaking it. This gave me confidence in the material.

I mounted the windshield on the handlebars–there may be alternatives. I used the same mounting techniques I used on my custom rear carrier using mostly 1-inch copper pipe, fittings, and epoxy together with some stainless nuts and bolts. See the carrier article for techniques for working copper pipe and with epoxy.

There are many variations on the design, mounting, and materials possible. I encourage you to explore them. Please report interesting variations.

I have not done the appropriate engineering to evaluate the mechanical operating envelope. I’m not sure of the structural integrity of the design at 65 mph for use with other scooters, but it doesn’t rattle, vibrate, or shimmy when I go 40 mph on the Metro. Based on my personally experience to date (about 200 miles over a month’s period with temps in the mid 30s °F), I would be comfortable with the design operating at speeds higher than those achieved by the Metro (i.e. 40 mph). PLEEZE — use at your own discretion.

The windshield shape:

I decided on a classic shape used on most large motorcycles because I was interested in making sure I’d stay warm and I’m sure windshield manufacturers spend a lot of time working out the aerodynamics. I avoided straight lines throughout the design and it helped with the looks a lot. I drew all sorts of shapes to start with. Feel free to experiment.

I included small “ears” at the bottom to protect my hands. This worked very well and I highly recommend them.

I used about a 3 inches curvature on the windshield but I think this is pretty arbitrary. See the picture below. (click on image for a closeup in a new window)

Parts list:

• Windshield: 1/8th inch x 24″(h) x 26″(w) — while not necessary for me, I probably would have used 28″ wide material. To get the right height, measure the height from the top of the headlight to your eye height when seated and subtract 1-2 inches.
• 1/2 inch copper pipe
- two pieces 2 inches long
- two pieces 6 1/2 inches long
• 2 - 3/4 x 3/4 x 1/2 copper T
• 2 - 1/2 x 1/2 x 1/2 inch copper T
• 2 - 1/2 inch copper street elbows. Street elbows allow one end of the elbow to fit into another fitting — it will be obvious when you see it, ask at the hardware store, they will know
• 4 - 1/2 copper elbows
• 4 - 3/8 x 1/2 inch copper reducers
• 4 - 1.5 inch stainless steel hose clamps
• 4 - 1/2 x 2 inch bolts (I used stainless steel - $1.50 each. You could use zinc plated but I wanted to protect against rust in my salt air environment). Cut the heads off. You could possibly buy “all thread”stock and just cut off 2-inch pieces. It’s easiest to do this with a sawzall with a metal cutting blade. You can also do it with a jigsaw. You will need to hold the bolt with a vise or clamp it to some heavy, stable surface to cut it. Doing this with a hack saw will take some effort because stainless steel is very hard. You could also use brass which will be softer and easier to cut. Brass is insensitive to moisture — i.e. it won’t rust.
• 4 - 1/2 inch stainless steel nuts — could also use brass
• 4 - 1/2 inch stainless steel “nyloc” nuts — again, ask at the hardware store. These are bolts with a nylon insert that keep the bolts from loosening (I’ve never seen these in brass)
• 8 - 1/2 inch stainless steel flat washers (or brass)
• 7 - 1/4 x 3/4 long hex head stainless steel bolts (could use brass here as well)
• 7 - 1/4 inch nyloc stainless steel nuts (brass is also possible here)
• 2 - 1/8 inch x 1 inch x 2 foot aluminum bar (I bought a 4 foot bar and cut it with a hacksaw.

Fabrication of the windshield:

You will need to have some tools including a jigsaw with an 8-10 tooth per inch blade and a couple of metal cutting blades. A vice mounted on a sturdy bench also helps.

• Lexan comes with paper glued to each side. Leave this on to the last minute to protect the plastic.
• Design the windshield shape. I did this on cardboard and kept fitting it till I was happy with the shape. I designed one side and used the cut offs to draw the other side to ensure symmetry. The picture below shows the shape of my windshield — it is the paper I took off the Lexan just before mounting it. It shows the holes. Your’s should be taller or shorter depending on you height (editor’s note - better to make it too tall if you’re not sure, you can always cut it down afterwards). The width should be 26-28 inches at the hand protectors (mine was 26 inches) regardless of the height since this is determined by the width of the handlebars.

I’m pretty convinced the shape is not that important as long as it is wide enough. I experimented with a variety from very aggressive narrow windshields to very art deco designs. I finally settled on a classic shape figuring that a lot of design thought and experimentation has gone into windshield design already and I wanted something that would have the wind-blocking performance I was looking for. I don’t have any way to send the shape I came up with. Draw the shape clearly with a single line on one side of the windshield. Once you cut one side, you can use the cut-off material as a pattern for the other side to ensure the windshield is symmetric.

(click on image for a closeup in a new window)

• Draw a horizontal line 7 inches up from the bottom of the windshield
• Draw a vertical line from top to bottom at the center of the windshield.
• Cut the aluminum bar into two 22 1/2 inch pieces (You could make one about 1/4 inch longer to account for its being longer on the outside of the windshield as the two ends of the bar match once mounted on the windshield). Sand the ends to soften the sharp edge.
• Mark the bolt holes on the aluminum bar stock. Mark one in the center and 3 equal-spaced points 2 3/8 inches apart on each side of the center hole (Note that I used 9 holes in my windshield but I think 7 is adequate.
• Drill the bar stock with a 1/4 drill at each mark for a total of 7 holes. Be careful the drill bit doesn’t wander when you start the cut. You could take a nail and dent the bar stock where each hole is supposed to be. This will keep the bit from wandering. There’s a tool for doing this, but if you don’t have it the nail trick will do just fine.
• Now, align the two piece of bar stock on the windshield along the horizontal line on the windshield and clamp on one end.
• Drill a single hole through the windshield and the other piece of bar stock using the drilled aluminum bar as a template.
• Now bend the aluminum bar stock into a smooth arc so that it is about 4 1/2 inches taller in the center than the ends. Do this with both pieces of bar stock. The exact depth is not too important.
• Bolt the two pieces of bar stock with the windshield sandwiched between them with a 1⁄4 inch bolt and nyloc nut. Don’t tighten too much - leave it just a little loose.
• Now bend the windshield to match the approximate shape of the bar stock and clamp the bar stock ends together with the windshield sandwiched between them. Make sure the bar stock is aligned with the horizontal line. Bend it such that the bar stock with the holes is on the inside of the bend. (Don’t worry about bending the Lexan too much. I couldn’t break the stuff by bending it in half when I wanted to throw the spoils away). When the windshield is aligned with the bend in the aluminum bars, clamp it all together at the free end with a spring clamp or vice grips. The entire assembly will spring back a bit so the curve is a bit gentler. Tighten the bolt and nut already in the first hole
• Drill the remainder of the holes in the windshield and outside aluminum bar stock starting at the bolt hole closest to the bolt already in place. Put a bolt through each hole and tighten it down as you move towards the other end until all holes are drilled. Use a thick piece of wood behind the outside barstock rather than your hand because the drill bit will come through the bar stock at a pretty good speed and could easily drill a hole through your hand.
• Now, disassemble it all, cut the windshield shape with a jigsaw (use a steady hand and go slow using an 8-10 tooth per inch blade). You might buy a little extra Lexan and practice a bit before cutting the windshield. I cut one side of the windshield and then used the cutoffs to trace the shape on the other side. This ensures the windshield will be symmetric.
• Sand the bar stock with sandpaper to give it that brushed aluminum look. You could also paint it if you wanted but this could be tricky when you reassemble it to avoid scratching the paint.
• Leaving on the protective paper, reassemble the windshield. Tighten all the bolts as you go from one end to the other.
• The windshield is now almost complete except for mounting holes to come soon.
• You’re done with the windshield. It is harder to describe than do. None of this is critical so don’t fret over it.

Making the mounting brackets:

• Using the picture below, epoxy all parts except the 3/4″ x 3/4″ x 1/2″ T. All parts are aligned in the same plane. I used two-part 5 minute epoxy. Don’t mix too much. If it starts to harden while you’re using it, toss the mixed epoxy and make another batch.

(click on image for a closeup in a new window)

• Cut the 3/4″ x 3/4″ x 1/2″ T in half as shown. I did this with a hacksaw holding the T in a vice. It would be tricky to do this without a vice.
• Mount the 3/4″ x 3/4″ x 1/2″ T on the handlebars with the hose clamps. Put epoxy on the street elbow and assemble it on the 3/4″ x 3/4″ x 1/2″ T. Do both sides. Now, approximately place the windshield against the bolts and swivel the bolts so that they will go through the windshield at a right angle. Let the epoxy dry for about 15 minutes so it is relatively rigid. (I used 5 minute epoxy on this job versus the 1 hour epoxy I used on the custom carrier.)
• Now hold the windshield up to the bolts and mark on the windshield for the bolt holes
• Drill 1/2 inch holes in the windshield for the bolts
• I painted the copper with silver paint.
• Mount the 3/4″ x 3/4″ x 1/2″ Ts on the handlebars with the hose clamps but don’t tighten too much yet
• Disassemble the windshield, remove paper, and reassemble.
• Put a stainless steel nut followed by a washer on 1⁄2 inch mounting bolt. Mount the windshield on the bolts.
• Put on another washer and nyloc nut. Tighten the nuts snugly but don’t over tighten.
• Adjust the winshield so that it has about the same angle as the Metro fairing. Now tighten the hose clamps and you’re done.
• The photos below show the mounting details.

Good luck. Michael

(click on images for a closeup in a new window)