Materials and parts

Frame materials

The choice of the frame material is up to you. But I found aluminum easy to work on and it does not have to be all that expensive ordering from a large supplier. It can cost considerably more buying in a local what I call 'chipboard' shop. Be sure to look around before you purchase any aluminum. If the total of all you need is in the region of 100-150 euro you did alright. 


But if you want to use steel or other materials the design will not change a lot.Combinations of wood, steel, aluminum are all possible.

The frame's main tubes I used were 40x40mm and 50X50mm aluminum profile. Imperial sizes it will be like 2" and 1.5" alu. For the cross member 40X40mm works slightly better then 50x50. It will give a little bit better turning radius. But 50mm will work just as well.
The wall thickness of alu tubing can be 3mm or 4mm. Any thicker and the frame start to get a unnecessary  heavy. It will also be more expensive. Aluminum especially is payed by weight.
 
The rear stays can be 50X50,40X40 or even 30x30mm. Larger diameter tubes won't make a lot of difference. Most flex is in the long main tube and boom. Don overbuild it.

Anything that comes close to this sort of tubing will work. And it does not have to be completely square tubes. Say if you have 35x55mm, you can use that.  Of course measurements will change accordingly. Do not simply follow the dimensions in the plans but keep altering things according to the size of the materials you got your hands on.

Support stays, seat frame, brackets, rear dropouts, and other small parts will work with lighter material when used in a double layer. In that case it often can be bought  at the local store. Don spend too much money on it. But it could come in handy if you forgot to order it with the rest. And of course a steel rod from the junkyard is perfect till you have some lighter replacement. Paint the steel and leave the aluminum as it is and it will look great.

Do not make the trike heavier then needed. Save weight trying to build light.  For example a 3mm wall for the main tube is quite enough for even the heaviest of rider. Where there is a problem you can insert strips, washers and stuff to reinforce the weak parts. In the worst case scenario you need to replace some of the main frame with stronger tubing. But is won be the end of the trike.

The trike can weight anything between 18 to 25 kilo. Put it together with modest materials and do the weightsaving overhaul once you are completely happy with the handling.


I have no idea what sort of aluminum the tubes are. I know there is 6000, 7000 etc. To me it is aluminum.


Here a rough idea how much you need of each size alloy.The dimensions are based on 20" front wheels with a 75cm track and a 26"rear wheel. Wheelbase something like 120cm.

Notice that things like the seat are totally up to you. I have used both square and round tubes. When built wide enough the square tubes won't hurt you back in any way. If you want a hardshell seat go ahead. The hammock type with nylon mesh is simple to make and cheap though. And I prefer it over any hardshell.

Nylon mesh is about 2 cents for a kilometer or two. Well, cheap anyhow. Step in a sailmakers shop that make tents, trailer covers. Not in a luxury boat joint. Though even there it may not cost you a fortune.


  Nuts and bolts

Avoid self locking nuts while you are still building. At certain spots self locking nuts are an excellent choice. We will get to that later. But the are very annoying and time robbing when you have to take a piece off again for the next treatment.

Most large bolts you can saw from a threaded rod.  Screw one self locking nut on to act as a head in case it is awkward to tighten. It is more work but saves some cash.  Allen bolts give a nice touch to the trike once finished. By then you will know how long they ought to be and how much you need. You may even want to have a bit of stainless steel hardware. That is up to you. 

Do not forget to put on a nut before you saw off a rod or bolt in case the thread gets damaged. Quickly grind the ends sharp edges off and it will work and feel smooth while working.

The steering knuckle L-profile.

This can be harder to find. At the moment Iḿ working on other types of steering for which you don't need such a thick piece of L_profile. But if you do find it it can be use for several parts on the trike so it doesn't hurt to have some waiting. Like for example the rear dropouts, brackets for the caliper brakes, and seat brackets. Beautiful stuff. You can built a spaceship with L-Profile and beat the Klingons every time.


The handlebars are regular 2.2mm round tubes. I happen to  have some square tube in which it perfectly fits. But there are workarounds. You can bend the round tube somewhat by filling it with salt ( or fine sand) in case you have some other design in mind. A 90 degree bent is awfully difficult though without splitting or denting the tube.

Plate material.

Don make the plates too thick. 5mm is what works best. The rear frame connection should not stick out to much or the chain will rub against it and the bolt heads/nuts. It is possible to set the rear wheel off center like on the Windcheetah. Looks very strange, but the trikes handling is the same. My rear wheels are not dished so I discovered later I always have them slightly out of the middle. Of course a dished wheel will also work. Ain't that great? We can do whatever we want.  


 

to be continued.  

SI (Metric)
kilometer (km)
meter (m)
decimeter (dm)
centimeter (cm)
millimeter (mm)
Nautical Length Measure
Nautical mile (nmi)
Fathom
U.S. and Imperial Length Measure
Mile (mi)
Furlong (fur)
Yard (yd)
Foot (ft)
Inch (in)
Mil