Home-built Tandem anyone?

[BrigmasterA]

So... My wife has decided we need a tandem bicycle, and the only 'affordable' ones are real plain straight-barred ones. I have a few frames, and I'm sure I can do it... Anyone know of any cheap plans or have any tips for doing this?
Thanks

 

[Markm]

I thought about cutting the head tube in half...top to bottom..then welding it too the seat post of another half frame.Then a bar across the bottom...

 

[BrigmasterA]

I thought about cutting the head tube in half...top to bottom..then welding it too the seat post of another half frame.Then a bar across the bottom...

I've thought of that too... The biggest question I have is with the chain setups...

 

[Markm]

just two double sprocket set ups...mountain bikes.....could even run gears if ya wanted... :mrgreen:

 

[Markm]

heres some-Thing I picked up. It was a welding experiment from Indiana State Prison....made by inmates. Its very rough and had single sprockets that I changed out, but they were close....

 

[BrigmasterA]

So one chain between the two sprockets and one from the back sprocket to the wheel right?

 

[Markm]

yea. That pic was before I changed it. I would stick to MTB donors. theyre cheap. :mrgreen: :mrgreen:

 

[MadMick]

I've heard a few horror stories which feature home built tandems. Factory tandem frames feature all overbuilt tubes, especially the 'drainpipe' which connects the two bottom brackets. If you can re-enforce this area the bike will handle better and be less likely to fail. Oh and good brakes!!

 

[jerrylee]

heres some-Thing I picked up. It was a welding experiment from Indiana State Prison....made by inmates. Its very rough and had single sprockets that I changed out, but they were close....

Let's hear it for our Hoosier prisoners!!!

 

[aka_locojoe]

I thought about cutting the head tube in half...top to bottom..then welding it too the seat post of another half frame.Then a bar across the bottom...

That's what I did here.

 

[user 135]

I used that same technique in college. We use onepiece cranks with a double sprocket in the stoker (rear) position. The frame had some flex but worked fine. Some sort of idler cog or derailer should be used to tension the front as Markm's has.

 

[BrigmasterA]

So I'm about 275, and my wife is about 125... Anyone have any suggestion as to what I should/could use as a heavy-duty tubing to connect the 2 lower gearsets together?

 

[Markm]

big ole square tube stock..?

 

[KZ1000]

While on this subject, Are Tandem wheels made different than regular, I would like to make my single speed tandem a 3 speed using a 26X1-3/8 wheels, should they handle the weight OK, Rick

 

[aka_locojoe]

I think tandem wheels typically have bigger gauge spokes. On my homemade I just used the wheels from the original bikes. We've really only ridden it one time for about 10 miles or so. The wife doesn't like to ride it because 1 it's ugly and 2 she's seen other things I've welded break :lol:

 

[MadMick]

While on this subject, Are Tandem wheels made different than regular, I would like to make my single speed tandem a 3 speed using a 26X1-3/8 wheels, should they handle the weight OK, Rick

More spokes usually but often with heavier gauge spokes too.

 

[C.S.]

Using off-road wheels on a street tandem should be a safe bet.
Suggestion: In addition to the fat tube at the bottom, weld two small diameter (1/2") pipes one on each side of the bike, from the top of the steering head to the rear dropouts, and connect them to every tube they pass on the way. that way it won't twist so easely.

 

[jdpcsm]

Here is my home-built tandem, made from two MTB that were on the trash:
before:


after:


was my first project I like it alot even know that isn´t perfect.

regards