XYZ Recumbent Trike

So I've been wanting a recumbent bike to help me get in shape. I'm far enough out of shape that a standard bike is uncomfortable to the point of being a deterent. The biggest obstacle to me is the price. Even the Terra Trike which is supposed to be an affordable, entry level option is almost a grand even bare bones. I tried looking on craigslist but even used ones rarely dip below 800. So I looked for something I could diy. My biggest obstacle on that front is I don't own, or know how to use a welder. I think I've found something promising though. 

There is a group in The Netherlands called N55. They are sort of a engineering/art collective and they focus on things to improve modern life. One of the projects they have out there is their XYZ Vehicles. They are pedal powered vehicles designed so that they can be put together with a minimum of tools. All that really should be needed is a power drill, some wrenches and a metal saw. From what I understand, they do classes where they build the 2 upright versions, the bakfiet and the tadpole design with the cargo box, but these are all over in europe and I am in Arizona so... I haven't been able to find anyone as of yet who has made one of the recumbents here in the states and posted about it. I would love to do this and post it as an instructable but I need some help. All of the materials list is metric and while I personally think a base-10 system makes a heck of a lot more sense that what we call standard measurements, I'm still not familiar with metric.

So my question to the community is, should I convert all the measurements to standard or is there someplace i can buy these materials from here in the states in metric sizes?

B I L L O F M A T E R I A L S :
B O L T S & N U T S
M6 SELFLOCKING NUTS, stainless (DIN985) - ca. 150 pieces (TWOSEATER: 200 pieces)
M8 SELFLOCKING NUTS, stainless (DIN985) - ca. 5 pieces (TWOSEATER: identical)
M8 NUTS NORMAL, stainless - ca. 5 pieces (TWOSEATER: identical)
M6 and M8 BOLTS with Hexagon head, stainless, (DIN931):
6mm x 140 mm - ca. 2 pieces (TWOSEATER: 3 pieces)
6mm x 90 mm - ca. 15 pieces (TWOSEATER: 20 pieces)
6mm x 90 mm - ca. 5 pieces in DIN 933 (full thread) (TWOSEATER: identical)
6mm x 60 mm - ca. 60 pieces (TWOSEATER: 120 pieces)
6mm x 65 mm - ca. 10 pieces (TWOSEATER: identical)
6mm x 40 mm - ca. 25 pieces (TWOSEATER: identical)

8mm x 120mm, 2 pieces (TWOSEATER: identical)
8mm x 100mm, 2 pieces (TWOSEATER: identical)
M6 WASHERS - ca. 300 pieces (TWOSEATER: 400 pieces)
M8 WASHERS - ca. 10 pieces (TWOSEATER: identical)
A L U M I N U M
2x25x25mm ALUMINIUM SQUARE TUBE: 15m (TWOSEATER: 34m)
3x30x30mm ALUMINIUM SQUARE TUBE: 1m (TWOSEATER: 2.5m)
4x60mm ALUMINIUM FLAT: 1m (TWOSEATER: identical)
2x22mm ALUMINUM ROUND TUBE Ø 22mm: 1m
P L A S T I C S
3x880x340mm POLYCARBONATE SHEET (TWOSEATER: 2 times)
ENDCAPS (PE), black, for 2x25x25 tubing: ca. 70 pieces (TWOSEATER: 100 pieces)
ENDCAPS (PE), black, for 3x30x30 tubing: ca. 10 pieces (TWOSEATER: 15 pieces)
POM or PE black, round Ø 25mm: ca. 0,3m (TWOSEATER: 0,5m)
POM or PE black, square 21x21mm: ca. 0,6m (TWOSEATER: 0,5m)
POM or PE WASHERS M8: ca. 20 pieces (TWOSEATER: identical)
M I S C E L L A N E O U S
AXIAL NEEDLE BEARINGS M8: 4 pieces (TWOSEATER: identical)
NYLON SPHERE w. screwthread, black, diameter 50mm: 2 pieces (TWOSEATER: identical)
NYLON RIBBON, black, width 25mm, for seat side support: 1,7m (TWOSEATER: 3,5m)

Picture of XYZ Recumbent Trike
0allbikes.jpg
Kiteman2 years ago

Outside the US, they *are* standard sizes. Just buy a metric tape measure, and cut your own parts.

dark8587 (author)  Kiteman2 years ago

That should definitely work for the tubing, I was mainly worried about the size tubing not matching and if that would cause any problems. I looked into it a little more and I think I'll be ok.

Don't blame the world for the US using the wrong system for measurements ;)

Simply convert the measurements and use nuts and bolts close to the original, there is always a suitable size at hand.

Some online charts for metric and imperial screw sizes will help, for the other materials a bit of calculating is needed.

Or as Kiteman pointed out use a double tape measure, one side shows metric the other inches - quite common here in AU.

dark8587 (author)  Downunder35m2 years ago

I didn't intend to put down the metric system, to be honest, I like it more than what we use. I just am not as familiar. I was hoping to use metric sized parts so I know all the measurements are dead on the same as the instructions given. I am just having trouble finding metric hardware and from what I understand most of the (US) standard measurements are close but never exactly the same.