DIY tandem or trike
 

Looking for info on building my own tandem and maybe a solo trike.

Because of my wife's health issues regarding balance, but still wanting to ride a bike, we decided to get a tandem. BUT, good quality tandems aren't cheap, and I don't want a Walmart type bike. I've read a bunch of stuff online, mostly through Sheldon Brown's stuff... The bike won't see high speeds, and won't see trail use. Mostly flat and slow bike paths.

I'm picking up 2 Trek 950s Monday. And believe I have a line on some chromoly tubing. My intention is to use a larger diameter tube (probably 1.5") for the main bottom tube, and possibly the same tubing to sleeve and extend the rear top tube to the seat tube of the front bike. I'm not sure if the front top tube needs sleeving. But I will add a brace behind the headtube to give some support between the top and down tubes.

The other part of the question... WHAT is required and where can I find parts to build a trike from a standard MTB frame? I have an older Trek 820 that would be perfect for this.

Good luck! Sounds like a fun project, though it might be easier to build from scratch if they make lug sets for tandems.

However, I notice that unless you are making your own lugs you are probably out of luck :)

Your basic approach to the tandem sounds fine. They don't fail as a beam; they just get squirrelly if they twist, and large tubes are good for that. With trikes, there's an inverse relationship between the percentage of bike parts and general desirability. There are seldom any substantial frame chunks in common, except for the upright styles.

In addition to Sheldon Brown's info (too bad the master has passed), I found this last night...
mattsbikes - Step-by-step: How I made a home built tandem bicycle on the cheap.
AND, he is in the Salt Lake area. I will probably try this method first, out of expedience. But can add tube and reinforce as I go. Now all I have to do is be patient till I pick up the bikes tomorrow!!!

Of the various bike parts resources, none have tubesets and lugs for tandem specific applications.

I found Atomic Zombie's website... WOW! Over the top on everything...
AtomicZombie Recumbent, Trike, Chopper, Scooter and Electric Bike Plans
I've looked at great length though this site and others, and think I have a good idea how to setup a rear for a trike.

Those two sites were the ones I was thinking of suggesting. I think you've found the best sites for doing what you're doing. Get to it! If I had a welder, I'd have a tandem already.

Great idea, and good resources. Good luck :D

Picked up the 950s last night. They are a little shorter than I wanted, but I can make them work. Remember, this isn't a speed machine or hardcore downhiller. Found a source for 4130 through an aviation supply house. Now if I could just find it locally. Downside, they are lugged frames. Upside, the lugs are thicker and easy to weld to.

Anyone know what the wall thickness of the Trek double butted tube is? I have a friend with some 1.5"OD .125" wall 4130 left over from a rollcage. I'm guessing this is going to be too heavy. But if I used it, it would be SOLID!!!! Looking for some tube about half that thick, and 1.25" OD...

And I've been in touch with Matt (built the tandem in the link above...). Good guy and good info.

I'm loving that StreetFighter Race Recumbent... that thing is sick, for sure. I might have to either buy those plans, or head-game the design and see what I come up with!

There is some incredible stuff on the AtomicZombie website... 20 years ago I might have even built a tallbike! But the build your own trike hubs I found very interesting. I know I can build a trike now if I have to, but hope I can find something that I can lighten (and maybe get a hubmotor to drive the front wheel)...

And a question. Has anyone used studded MTB snow tires? I've never seen them before and ought to go get a pair of them for next winter. Novel at least...