Introduction: Laminated Wood Bicycle Mudguards

This instructable will teach you how to make a set of beautiful wooden mudguards/fenders for your bicycle.

Its a work in progress. I will finish the mud guards in the next week or so, updating as i go along.

My inspiration came from this guy.

Earlier this year, i built a bamboo bike from this instructable, although mine is a fixed gear . Now, i am planning to do some bicycle touring on it, so i need to outfit the bike in an appropriate way. 

Why make fenders?
Because nice fenders are expensive. Because my bike is home made so standard fenders wouldn't mount easily. Because i like making things. 

Why make wood fenders?
Because wood is beautiful, and will go well with a bamboo bike. Because i love working with wood, and am well set up to do it.

My fenders are 1.5 inches wide, and approximately 1/4 inch thick. they are designed to cover 3/8 of the diameter of my wheel. they have an inside radius of 14 inches, which is perfect for a 700c wheel with size 23-25 tires.

They are laminated (a process of gluing several thin layers of material together to form a thicker piece. this also allows the glued up wood to be bent around a form or mold and clamped until the glue dries, leaving a laminated piece that will stay curved) from three layers of wood. the top layer has a "racing stripe" pattern made by alternating light and dark wood across its width.

These plans are simple to adapt for, say, chunkier mountain bike tires.


Step 1: Materials and Tools

Materials
Wood -- I am using beech, a light colored wood, for the majority of the fender, and Brazilian mahogany for the darker racing stripe.

Plywood -- for making the form to bend your wood around. since my fenders are 1.5 inches wide, i used to thicknesses of 3/4 inch ply i had lying around.

varnish -- I am going to use some marine-grade spar varnish left over from another project.

glue -- normal wood glue, doesn't need to be waterproof.

screws -- for joining the two thicknesses of ply, alternatively they could be glued. make sure they are long enough to reach through to the second peice of ply, but short enough not to poke out the other side.

drill bits -- for drilling pilot holes in plywood to accept screws. size depends on thickness of screw.

tape -- masking or duct, to glue-proof certain things you don't want glued

thin (1 or 1.5mm) stainless steel sheet -- for making a mounting system. i also purchased "sheldon fender nuts" for the mounting system

Tools
drill -- for drilling pilot holes for form. dremel would work too. also needed for mounting system.

jig saw -- for cutting the curve into the plywood for the forms. could be done by hand with a coping saw. you probably want ear and eye protection with that too.

wood plane and table saw -- to cut and shape your wood to the correct dimensions. or do it the easy way (i did) and get a local carpenter to do that bit for you. also consider constructional veneers, which can be bought in thicknesses up to 2.5 millimeters, but are a bit pricy. you may still need the plane any way you do it.

sharp utility knife -- for cutting the strips to length.

clamps -- a good number. i used 10, of various types, mostly spring clamps, and a few
bar clamps.

circle-drawing device -- i didnt have a compass big enough, so i improvised with a pencil, a nail and hammer, and a length of string.

measuring tape

set square ---or triangle, to draw right angles

pencil

sand paper -- i used 80 and 240 grit, its what i had. and a small block of wood to use as a sanding block.

screw driver -- that works with your screws

rag or paper towel -- for wiping off superfluous glue


Step 2: Getting Started: Planning and Measuring

After puzzling how to mount my fenders so that they didnt interfere with my brakes, i decided that each fender would be made as two separate parts, one bit behind the brake, one bit in front. in the front of the bike, those pieces would mount via a metal plate onto the brake bolt. but because of a peculiarity of my bike, the rear ones would have to clamp onto the seat stays of the bike. as i said earlier, i wanted 3/8ths of each wheel to be covered by fender. i divided this up as 2/3 of the fender behind the seatstays (or front fork) and 1/3 in front. i calculated that with a 14 inch radius, the longer piece of fender would have to be around 20 inches long, and the front piece half that. so to outfit my bike, i would need three 20 inch fenders, one of which would be cut into two pieces, with half going on the front wheel, and one half on the back wheel. I also decided to make a set of fenders for a friend, who also built a bamboo bike, and will be my touring partner. so i needed to make six 20 inch fenders to outfit both bikes.

so this is the stage at which you need to figure out how much wood you will need. because of my racing stripe, i needed wood 1.5 inches wide and .5 inches wide (so that a light-dark-light pattern on the top layer would still be 1.5 inches wide).

here is how i figured out how much to get:

 each 20 inch fender needed:
 2 layers 20"x1.5"x1/8"
 1 layer formed of 2x 20"x.5"x1/8" and 1x 20"x.5"x1/8" of a different(in my case darker) wood
                     X
3 fenders per bike (split between both wheels)
                     X
2 bikes
                     =
10 linear feet of dark wood in .5"x1/8" 
20 linear feet each of same light wood in .5" and 1.5" x 1/8" wood


I got a little extra of both woods in all widths, just in case i messed anything up.

Step 3: Making the Forms

Assuming that you got your wood precut like i did, and i dont have the experience to tell you how to do it if you want to do it yourself, the first step after finalizing your dimensions will be to make your form.

you will need the plywood, the tape measure, the pencil, string, nail, hammer, screws (i used three), drill with appropriately sized drill bit, and the jig saw.

bang your nail into your ply, and measure a point 14 inches (or whatever you decide on for your radius) from it. tie the string around the pencil as close to the tip of the pencil as possible. i used a round turn two half hitches. then, making sure the pencil is at right angles to the surface of the ply, take up the tension on the string, and then wrap it securely around the nail. keeping one hand on the nail end of the string to stop it slipping, carefully draw out your section of circle. i drew what i thought was the correct length, then used another bit of string to measure around the curve. it wasnt quite 20 inches, and i wanted a few extra inches on the form, so i drew an extra bit and re-measure. i think it was around 24 inches along the curve.

from here there are two ways to proceed. either reposition the nail, and do the whole thing again, or if you are lazy, whip out your jig saw, cut the curve, then use it to draw the next one. i did the lazy way. one thing to note: for the base of the curve, i just drew something on by hand, with no care. this caused problems. you can draw it by hand, but try to make sure the two bases are similar or you will have trouble getting clamps to stay. also, pay attention to how thick your form ends up, because if you have small clamps, you my have trouble getting them around the laminated wood and the thick form.

once you have your two plywood curves cut, play around with getting them to line up smoothly. once you are satisfied, clamp the pieces together. once they are clamped, mark the positions for your screws and using the drill (or a drill press as i did) drill your pilot holes, all the way through both pieces. then, with the pieces still clamped, screw in your screws. now, you are ready to begin laminating.

Step 4: Beginning Laminating

for this you will need: your newly constructed forms, your wood, tape measure, pencil, set square or triangle, knife, glue (and something to spread it with if you don't want to use your finger), clamps, duct or masking tape, bits of thin scrap wood for shims.

start off by cutting your wood to length. you can do this two ways. you could cut your wood too long, planning to trim it down at the end or you could cut it more precisely, making the most efficient use of your wood, and saving yourself work later. i chose the latter.

i wanted 20" long fenders. but i did not cut every layer to 20". this is because each successive layer goes around a larger radius curve. so my bottom piece ended up being 20 inches, and each successive layer was 1/8" longer. 

so i marked up the lengths, used the set square to get a right angle line, then cut the pieces with the knife.

before i started gluing up my pieces, i added in a step. i took one of my left over lengths of 1.5" wood, and covered it with tape to glue-proof it. i used this as a fourth layer that would both protect the top layer from being marred by the clamps, and spread out the force of the clamp more evenly.

the glue i used only required that one surface be coated, but check yours. so
i covered one surface of the bottom layer, and one of the middle layer. this means the more fiddly, three piece top layer didn't need glue on the bottom. however, i did dab a little glue onto the thin edges of the mahogany piece, to make sure the strips stayed together, edge to edge. i aligned the ends of my pieces, then added my fourth, glue-proof layer on top, and placed my first clamp in the middle of the form. then i put clamps on either side of that one, about half way to the end. on each end, i used my heavy duty bar clamps. then i started filling in the gaps between those 5 clamps with other clamps. i looked for places where the three layers of wood weren't pressed tightly together. in some places i had to use my little wooden shims to get even pressure all over. i wiped off all the glue that had been squeezed out. then i let it dry. for about 12 hours with my glue. once again, check yours.

after it was all dry, i removed the clamps and my glue proof strip, and viola! the fender came right off, and looks great. it is very stiff, there is almost no flex along its length, which is great.


Step 5: Advanced Laminating

This section will cover a couple topics. the first is what to do if you have made your form, but you decide you want to make mudguards that are longer than your form. the second is all about getting fancy. Not satisfied with just a racing stripe? i'll show you how to do some more interesting patterns.

Over-sized Mudguards
I'm only including this section because this happened to me. after making my first mudguard and test fitting it on my rear wheel, i figured out a way to have my mudguard go as one piece all the way around my rear wheel. but now i have made my forms too small for a mudguard that long. not to worry. there is no need to go and make a new one, and in some ways this way works better than when the form is the "correct length." however, this method does require at least one very long bar clamp. 

Essentially,  i did everything exactly the same, except had the ends of the mudguard stick out on either side of my form, and then used one long clamp to pull both ends
towards each other, following the curve of the form. one thing to note is that the mudguard aught to be centered on the form, i.e. with the same length of fender sticking out beyond the form on each end. 

Getting Fancy
I decided to make one fender with a more complex pattern. the top layer will still be a racing stripe pattern, but it will be interrupted by slanted dashed lines composed of alternating light and dark parallelograms. (pics coming soon if you cant visualize it).
This is where you an get really creative, and come up with something unique and tailored to your tastes.

If you end up with a complex pattern that is hard to keep organized, you can stick all of the pieces onto a piece of tape for the entire lamination process. 

As far as i know, this has never been done before! so i have no idea about how well the lamination will stay together with all those separate pieces. i made this with bits of extra wood, after i had made all the fenders i needed. so if it breaks, i have a replacement anyway.

Step 6: Wood Finishing

The first step is to tidy up the wood on the mudguards, then to waterproof them. 

Trimming the wood
I will refer to a few different parts of the fender in this section. by "edge" i mean the long, thin edges. by "end" i mean the short stubby ends. "top" means the outside of the curve -- what will be visible on the finished bike. "Bottom" means the inside of the curve, which wont be visible. 

To trim the edges, i used a wood plane. adjust the blade so that it only takes of the tiniest sliver of wood. then, hold the plane in one hand (i use my left, being right handed) and the fender in the other. bracing the plane against your body, draw the wood along 

Step 7: Mounting Your Fenders

I went ahead and figured out how i was going to mount my fenders, before i treated my wood. there were several reasons for this. firstly, i knew i would be drilling through my fenders, and i want to be able to treat the inside of the holes to prevent rot. secondly, some parts of my mounting system are permanent, so i wanted to treat underneath those pieces. 

Here is how i went about devising a mounting system. this is certainly not the only way, and may require tweaking to work with your bike. 

First, i ordered Sheldon Fender Nuts made by Problem Solvers. you can find them easily online, and although they are pricy for what they are, it makes for a slightly more elegant mounting system. 

The basic system 

Comments

author
Lost+Moai made it!(author)2011-06-26

I'm thinking of doing this minus the plywood form. For the sake of scrap wood preservation and laziness, I was contemplating using the bike's wheel for the form. I don't know if I'll leave the tire on or not, but either way I'm going to try clamping it down using a tie-down strap wrapped around the entire circumference. Think it'll work?

author
redskyes made it!(author)2012-08-17

I've made a version (not quite as nice as these!) of wood fenders using the wheel as a form, leaving the tire on the wheel and taping down a spare length of bicycle (or motorcycle for more room) chain along the length of the tire between tire and wood to build some space while keeping the correct shape. It takes some finesse while clamping but worked like a dream!

author
adie.mitchell made it!(author)2011-06-26

I think thats a great idea...simplifies things a lot. make sure not to get glue on your wheels! and I would use clamps...not tie downs, as you do need quite a bit of force. By the way, i have now used these fenders on a two month, 3000 kilometer bike tour of france and spain. I had the fenders on the bamboo frame i built. check out my blog

bamboobiketour.wordpress.com

Adie

author
Datum made it!(author)2012-07-05

I was making my own set based on your directions, and I found a novel way to clamp the wood down while it dries. I ran out of normal clamps about halfway through, so instead I found a ratchet-strap in my garage and figured out how to secure it around the whole mold. Once around, I tightened it as much as possible, so instead of multiple clamps providing localized pressure I had a single strap providing equal pressure around the whole thing. Worth a shot if you're building more!

author
adie.mitchell made it!(author)2012-07-05

yeah thats a good system.
Ezra at fastboy cycles (s\check out his fenders, they are sweet) has a system that uses a long metal ruler, which is bolted down at each end, giving similar pressure through tension.

hope the fenders worked out.

author
nduetime made it!(author)2010-12-28

How did the parallelogram pattern strength hold up once finished?

author
adie.mitchell made it!(author)2011-09-27

strengthwise it seemed ok, it just didnt end up very tidy, i never used them because i had enough of the normal pattern.

author
sparta.rising made it!(author)2011-09-27

What are you using for fender stays?

author
adie.mitchell made it!(author)2011-09-27

i used 3mm thick stainless steel rod that i got at a metalworks/welding place. i drilled through the fenders, threaded the rod through, bent it 90deg on either side of the fender. then i got some 1mm thick stainless sheet metal, and cut rectangles, about 20mm by 15. towards one end i drilled a 3.5mm hole for the end of the stay, towards the other end, a hole that matched the bolt holding my rack on. i threaded the rod through the hole in the plate, cut it to approximately the correct length, bent it 180deg back onto itself so it couldnt come off, then bolted it to the rack braze-on. to fine tune the stay length, you can just rotate the plate around the mounting bolt.
I realize that's quite wordy. if you are actually making these, and are confused, i can dig up some photos.

Adie

author
BAMBOOBIKER made it!(author)2011-07-21

Hey, thanks for the link over to my instructable. It makes me wonder how many others have built bikes? I'm about to dig into your fender instructable to throw some fenders on a coulple of my frames. These look nice, and easy to do! I'm probably going to go Carbon and Wood laminate, just for something a little different! Not sure how it'll work out, with such different materials, but worth a shot! Thanks again for the link, and for this well written instructable!

Eric

author
adie.mitchell made it!(author)2011-07-21

hey, the fenders are really great, they go great with the bamboo. thank you for your instructable! I built mine fixed/free and took it on a two month bike tour of france and spain, the frame held up really nicely!

author
BAMBOOBIKER made it!(author)2011-07-21

I've spent the last hour or so reading your blog from the trip, and it sounds like an absolute blast, but also incredibly difficult on a fixie! Good job! Are you still riding the bikes?

author
adie.mitchell made it!(author)2011-07-22

Yep, I ride about 20 miles (commuting to work) 4 or 5 days a week. Doing it on a fixie was definitely tough! Although the tour was great fun, all the most dificult and least enjoyable bits (hills, lol!) would be so much better on a geared bike!

author
Leemister made it!(author)2011-03-29

You know what this reminds me of? A body of a long bow. If you make an instructable on how to do that, tell me. Cuz I've been trying to find out how to make a long bow.

author
plasticpopcorn4 made it!(author)2010-10-02

What kind of elasticity did the finished product have?

author
adie.mitchell made it!(author)2010-10-03

its pretty damn stiff, id say. you have to actively try in order to make it bend.

author
hassi made it!(author)2010-10-01

Just one quick question (after the following compliment). Looks grand!

Now the question...How did you calculate "spring back?" That is to say, when one removes the final laminated piece, there is invariably a degree of relaxation wherein the final piece does not retain the exact curvature of the template. How did you calculate that or did it just work out? Inquiring minds want to know...

To reiterate, great job...Looks grand!

author
adie.mitchell made it!(author)2010-10-02

thanks,
and i didnt make any calculations. i just used the radius of the tyre, knowing two things. a) that it would "relax" when taken off the form, as you said. b) that i would mount my fenders with approx .25 to .5 inches of clearance, so the "springback" would approximately match the effective radius i was after. it wasnt particularly scientific :)

--Adie

author
hassi made it!(author)2010-10-02

Many thanks for your reply and explanation...I must try this...

Again, good job on an excellent project...

author
Hiroak made it!(author)2010-09-30

Wood these be strong enough for a motor cycle?

author
adie.mitchell made it!(author)2010-10-01

well, the nicke thing about laminating wood is that you can do as many layers as you like, and it just gets stronger and stronger. as it is, with three layers of wood, they are very inflexible, and if you had a sturdy mounting system im sure it would work!

author
allbeef made it!(author)2010-09-19

this is amazing, i was just cleaning out my work space and stumbled on some walnut and mahogany veneer, i also happen to be in need of fenders haha! im excited to see how you mount them.
good luck!

author
adie.mitchell made it!(author)2010-09-19

I'm excited too! heh, i think i have a system that will work. we shall see :)

author
Archergal52 made it!(author)2010-09-17

Whew! I am VERY interested in how you do this, so I'll stay tuned for updates! Thanks!

author
adie.mitchell made it!(author)2010-09-17

thanks! i hope i dont dissapoint :)

author
Archergal52 made it!(author)2010-09-16

Did I miss something? This seems incomplete.

author
adie.mitchell made it!(author)2010-09-17

correct. i will be adding pictures and more staps as i get to them. i was surprised they featured it given how incomplete it is!

author
f3rg made it!(author)2010-09-16

Yep, definitely not a complete project. I'll stay tuned for the rest, though.

author
adie.mitchell made it!(author)2010-09-17

yeah, i just started yesterday, should finish this week. ill be updating as i go along.

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