Hand made wooden Mudguards / How to make thread.

Hi again ,
Ive had a few people ask me how I made the wooden mudguards on my Rotrax so i thought id share the process. I never took many photos during making them but here goes -
So firstly if i start with the mould.
Here-




This is made from a sheet of 3/4" sterling board (cheap ply) and Its two layers glued and screwed together which gives 1 1/2" (40mm ish) thickness, enough for the width of the mudguard.
I used a glue called d4 on this mould, although anything will do like Pva, or gorilla glue etc, and also screws to pull it up tight.
So depending on your wheel size? mine are 27" , I measured the diameter of the wheel including the tyre inflated and added on about 10-15 mm, enough for the mudguard to be clear of the tyre when mounted.
Then glue and screw both pieces of board together (oversize)
Then using a string, a nail and a marker pen, mark out the circle on the sterling board (to the diameter of your tyre including the 10-15mm clearance)
The diameter of my mould is 705mm.
Then cut out the circle using a jigsaw, and finish off with a belt sander to a smoother & neater finish.
Once the glue is dry you can remove all screws , this allows you cut out the middle sections as shown so you can handle the mould easier and they are lighter to work with.
Now the Mudguards-
I used Mahogany & oak -



The mahogany i used is from and old window cill that i had in the garage, i used my circular saw to rip thin strips off then reduced them further with the belt sander.
The oak is from the top layer of engineered oak flooring left over from a job i was doing. I managed to prize off the top layer (i did soak them for a day or so which helped) then cut and sanded again in to strips.
For full wrap mudguards you need the lengths to be -
Front 700mm & rear 1200mm
The thickness of the strips i ended up with were about 2mm or just over( just enough to get the bend on without them breaking)
And they were about 40mm wide
To achieve the stripe finish which i chose. i had to cut one of each strip (mahogany and oak) into narrower strips then place one between the other two for the top layer section of the mudguard , but its probably easier just to make plain ones -

The thickness of this cut section measures 7mm thick & 35mm wide.
So once you have strips ready they are good for glueing around the mould.
3 strips per mud guard
I used normal pva wood glue, cheap and very strong.
Lay the strips on a flat surface & use a paint brush to apply the glue evenly all over with no gaps or debris.
First strip which is the bottom layer, apply to the top side only (don't want to stick to the mould) ,
Second strip - the middle layer, apply to both sides and place on top of the bottom strip (glue to glue). Then the top strip, again one side only and place on top of the middle one (glue side down).
Then push down on them and give them a slight side to side movement to get the glue evenly spread & compressed, clean of excess glue with damp cloth.

Stand the mould up vertically & lay the mudguard onto it, starting from the middle use tape (i used electrical tape) and tape it nice and tightly around the mould every 4 inches or so, working your way along to the end & then back to the other end (that's where the cut out sections on the mould come in handy).
They should pull the strips down nice and tightly to the mould , you can fit both mudguards around the mould so may aswell do both at the same time.
Then wipe off all excess glue again. Then as a final securing device , i used a ratchet strap and placed around the whole mould and pulled it tightly.
I left mine for about one week as I was busy, but i think a couple of days would be just fine.
Once the glue is dry you can remove the strap and tape and then begin shaping.




I used my belt sander to get the slight curve on the top of mine,
Using electrical tape again i secured the strip onto the mould and worked in small sections as its hard to run the sander right round the mould due to the tape.
I secured the mould upright to the side of a bench at standing height to make it easier for working with.
Once i had a fairly good shape i just sanded by hand going up the grades to a finer finish until you are happy.
The finish on mine is just normal clear wood varnish , 2-3 coats.
And that's about it for the woodwork side,
Then its making the brackets, I used 22mm copper pipe rolled out and polished, then shaped using tin snips and bent in the vice & edges filed smooth.




The rivets i used are 5mm flat headed copper. At first i tried to use a rivet punch but i found that i could not get the dome shape as the rivet shank just kept bending and there was a risk of splitting the wood so instead i resorted to using a ball pein hammer to flatten it off which worked a whole lot better & i left about 3-4mm protruding to do this.

Quick refresh in some dimensions-
Strips before shaping= 2mm thickness 40-45 mm wide
Front length 700mm (best to over length, say 750mm)
Rear 1200mm (same again 1250mm)
After shaping = width 35mm

Mould diameter = 705mm , thickness 1 1/2" (40mm ish).

And now mounted on the bike-





Thanks for looking and good luck if you give it go

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viewtopic.php?f=12&t=298673

Re:

This kind of advanced guru woodworking terrifies me, so I don't think I'll be attempting this! Still, seriously impressive stuff.

Absolutely gorgeous .... chapeau indeed

Re:

Fantastic work! ..well beyond my 'woodworking' abilities of hedge laying and coppicing though!

Beautiful Rotrax you have there.

Very nice indeed fellow maker of mud protection


Well,ive experimented in one but put it on the back burner till i can sort out a workshop or bench space and ill be doing my own . Being a cabinetmaker i'd have to add something exotic for the top waterfall bubinga or something such

On the first prototype i made i used a former with a convex surface to create the curve on the underside. I though this would either do away with sanding or help it by having it started and making the underside curve more pronounced :? A working prototype showed that the rain came straight out the sides when the underside is totally flat.
Gluing it is difficult though, and if i produce more ill have to go the route of sand bag. or thinner more flexible veneers.
I also looked at using standard mudguard fittings which can be easily found in the bike recyclers.


Anyway, very nice indeed Well done.
I will add though it may present no problems but mahogany is close grained whereas oak is open grained. I wouldnt think they'd split but the will move differently and that may cause problems. :? Just a top of head though

Re:

Hi Dyna-ti

This sound very interesting by going down the route of a curved underside. I think this would be beyond my capabilities with the tools i own , & im a carpenter/kitchen fitter so a little less detail involved than a cabinet maker i guess .
A friend of mine who's an electrician and doesn't own or ride a bike liked the mudguards but then told me that i should of made the underside concave using a router :facepalm: It was easier for me to agree with him
The close grain & open grain you mention has slipped my mind, its been 25 years since my apprenticeship & yes I do have a slight bit of twisting, I think this occurred when they were left off of the mould whilst making brackets etc, they seem to be ok now they are varnished & mounted , touch wood.

So what is an exotic waterfall bubinga :?: , or do you mean some fancy detailing.

Be sure to post them up on here when you get around to completing them.

Thanks.

I favour the method of sanding the top from square to curve it. It means you can use different thicknesses of veneer with different colours.
eg You start off with a couple of layers of the same species and in something very close grained, the harder the better. It will be taking damage hits from gravel and the like being flung at it and then constant immersion in water so whatever that surface is it better be hard wearing. Maple would be a good choice and a few layers will mean its maple all the way through the curve when you machine it on.
Above that given the maple is creamy white something contrasting it would be nice. You might want to continue that then add in the odd slice of maple for a thin white line running around it.
For your final you would use a strip of exotic say 1/2 as wide as the total width then 2x 1/4 ,one down each side
the curve will only touch the edges of these so the exotic strip (read expensive ) isnt wasted, A thick veneer could be used here ,bookmatched :?


Im sure you had a google for ideas for this. Did you not come across anything quite visual ?


Pic of a laminated spoon, the sides constructed with about 20 layers of 0.6mm veneer around a former. Finished spoon the former forms the base and is permanent/was worked prior to gluing up.. A later prototype went on to include a white strip running through it. I wasnt limited to smooth curves so could dig deeper on places accentuation more of the contrasting in different spots

2nd pic is bookmatched Snakewood


Bike looks great by the way The mudguards are its crowning glory in my humble opinion. The look like they belong and now weve seen it would look lesser were they removed.