I’ve seen this search/request come up a number of times before so figured I would put the information on the blog since I’m writing it up for an in-house project anyway. Enjoy!
Tools: straight rule or yard stick, tape measure or cloth tape, tools to remove your seat and paper & pen to make notes. (Optional: piece of posterboard to make your pattern).
Step 1) Measure the distance from the back of the seat to the rear pillon bolt (if you have one). This measurement tells us the maximum length of the ‘visible’ area of the fender bib.
Always measure to the center of bolts/holes if possible.

Step 2) Measure the width of the fender from each vertical side to the other. Now, from that measurement we’ll subtract 2 1/4″. This determines the maximum width of the bib also allowing space for the 1/8″ thickness of the edge lacing. I have found that leaving about an inch exposed on the sides of the bib leaves a good amount of fender showing to help “frame” the bib.

Step 3) This one will take both hands but you won’t be holding a camera so you have an advantage already…measure the curvature of the fender itself by laying a ruler from the back of the seat to the seat bolt (measurement from Step 1) and then use a second ruler/tape measure to measure the height of the curve. This isn’t necessary if you’re making your own bib, it’s for those folks that want to have a custom one made by me. This tells me how much to roll the bib after it’s made so it lays on the fender a bit better out of the box.

Step 4) Remove the seat and measure how much area there is from where the seat ends down towards the engine. It’s nice to be able to secure the from of the bib somehow so either pressure fit, velcro, existing bolts, etc. can be used. Notice on mine, I added three inches to the step 1 measurement to get the overall length (the back of the seat is 1″ away from the card holder). This is because I am planning a custom seat pan and may move the back of the seat forward an inch or so. Leaving room for changes! Note the position of any bolts/ holes, etc. if there are any so they can either be avoided or used in the bib design.

That’s it. From these measurements & notes a custom bib can be designed for any bike. All I need to know after that is what kind of profile to give it; triangle, U-shaped, rectangle, spade, etc.
Now, for those folks looking to make their own bib and have their measurements and a blank sheet of posterboard…MOST IMPORTANT THING: fold the posterboard in half and only draw one side (left or right lengthwise) of your pattern. Layout all of your stud holes, lacing holes, buckstitch, etc. with it folded in half. Why? Because by folding it first and punching all of the holes, cutting, and so on with it folded in half it will automatically make a mirror image on the opposite side. All of your curve, hole placements and the other details will match exactly. Nothing looks worse or distracts an eye more than that one chrome stud that is off by 1/8″ from the rest. Make the pattern right and everything else is a piece of cake. (For those curious, the picture is of a tank bib but the rule is the same…fold in half first!)

Now, what about those fancy curves. Well, best way is to buy a French Curve set from your local art/craft store. They’ll set you back about $10 for a plastic 3-piece set and are well worth the money if you want to draw smooth flowing curves and change directions mid-curve. If you’re too um, “frugal”, to buy them then many things like coffee cans, soda cans and packing tape rolls make good circles and you can use them in conjunction with a straight edge to make transitions. Honestly though, just spend the $10 bucks especially if you even think you’ll want or need to make another pattern or heaven forbid, replace the one you’re making now.

Have fun with it and feel free to post questions/comments below. For questions on pricing or custom designs click here to contact me.
~Chris