This bike is a fun twist on the classic tandem, and creates a more 'intimdate' and team oriented approach to the old two people one bike problem. The bike can be ridden with the peddler facing the pilot or the peddler seated on the handlebars.

For the design. I don't have the skills or resources for welding, which has always been a huge hurdle in approaching fully functional bicycle mods. I suspect I am not alone in my desire to create awesome things that dont need welding skills or special tools, so here it is if you have two bikes and a free afternoon you can build this simple design too.

Supplies

two bicycles of about the same wheel size (partly or mostly functional, you can see in photos one bike that was missing the bottom bracket)

seat post clamp

hanger iron straps

wrench set and or allan keys/ wrenches (one for removing the axel bolts, and one for tightening the post clamp)

mallet

soemthing to cut through the frame of the bike (one of the following):

-metal hacksaw

-sawzall with metal cutting blade

-angle grinder with metal cutting wheel

-other simlar tool that can confidently and safely slice through your frame

safety glasses

work gloves

block of wood (scrap 2X4)

mallet (or other striking tool, i.e. hammer, bat, etc)

helpful working knowledge of the names of the parts of a bicycle frame

use labeled image as guide, image taken from https://en.wikipedia.org/wiki/Bicycle_frame

Step 1: Cut Off the Front End of One of the Bikes

This is a great way to reuse a bike with a damaged front end, or missing front end (handlebars, fork, wheel, etc.), I recommend choosing the bike with the less functional front end to be cut, but with a functional back end, since thats the part that will be driving the bike.

Cut the front end off. if using electric tools wear protective eye wear.

Cut the top tube as close to the seat tube as possible without causing damage to the seat tube.

Cut the down tube as close as possible to the seat tube without causing damage to the chain or gears, I left a nub on mine the height of the larger gear in case I wanted to add some additional mods later on.

Step 2: Remove the Seat From the Bike You Just Cut

Remove only the seat from the cut bike, Leave the seat tube on the frame.

Step 3: Remove the Front Wheel of the "base Bike"

To avoid confusion the bike you just cut will now be referred to as the "cut bike" and the other still intact bike will be referred to as the "base bike".

Remove the front wheel of the base bike axel and all. You won't need it for this project.

Remove the rear wheel of the cut bike (you will be putting it back on but it makes it a little easier for getting the next step right)

Step 4: Fit the Fork of the Base Bike Over the Rear Wheel of the Cut Bike

Most likely the fork on your base bike wont fit over the rear wheel/hub of your cut bike, if it does you are very fortunate and can skip this step.

Sometimes you can manually pry/force the fork to sit on the axel of the rear wheel. but in most cases you need to stretch the space between the forks a bit. this can be achieved with a block of wood and a mallet.

Place a wood block, I used a scrap bit of 2X4, between the forks, so it sits perpendicular to them. then tap or gently strike the center of the block of wood, till the forks begin to stretch apart. Continue till you achieve the necessary distance to fit over your rear wheel hub on the axels. Try to stretch in an even manner, so as not to compromise the strength of your finished product.

The fork is going to sit on the axel of the rear wheal sandwhiched underneath the chain /seat stays of the cut bike that will also share that axel. You only need to stretch the fork wide enough to fit over the rear hub to be tightened down on the axel.

You might also need to stretch the rear stays of the cut bike to fit over the fork. Use the same stretching method of wood block and mallet. Stretching it a little will make the next step much easier.

Avoid over stretching too much as you will have to squish it back down later.

Step 5: Assembling the Two Frames Onto the One Rear Wheel

This is probably going to be the most difficult part.

If you have a chain tool and are confident you could unlink and relink your chain it will make this step a bit easier.

if you dont have that tool or confidence, you don't need it, I didn't use one either. Put on your work gloves, drink some water and stretch, its time to get to work.

You are going to sandwhich the two bikes onto the cut bikes rear wheel axel. the fork goes on first. the cut bike goes on second outside the fork.

The method that worked best for me was to first put the rear wheel back on the cut bike with the chain in place correctly as it was.

Then (and this is why stretching the cut bike really helps) remove the bolt off one axel, and loosen the other side as much as you can then force the fork onto the axel the side with the loose bolt first to sandwhich between the cutbike frame and the hub.

The other side the cutbike frame might slip off a little its okay you can force it back once you get the fork secured and one side tightened down. If you over stretched the frames this might be the part whereyou ahve to squish them back down, a clamp will come in handy or having a partner put weight on it with it laying on its side.

Tighten it good, make sure the chain is back in place, and you can turn the wheel with the crank. Adjust if necessary.

This will take a bit of finagling, its the hardest step so once you get it, you are mostly done.

Step 6: Connect the Seat Tube of Cut Bike to Handlebars of Base Bike

Full disclosure I dug through my random parts and used what I had that would do the job, and then googled what these parts were for the instructable.

a hanger iron strap ( I had to use two scrap pieces 6 holes in length and bolted then at one end, cause I didnt have one long enough piece that i could bend around the handlebar, but if I were to rebuild I'd try to find one long piece as explained here)

Attach the seat post clamp to the seat tube of cut bike.

Wrap/bend the hanger iron strap around the handle bars of the base bike and have the two ends of the strap meet in the middle to reach the seat tube clamp

Thread the hardware of the clamp through both the clamp and the strap.

Tighten this up as tight as the clamp allows, otherwise your tandem partner may pull the clamp off.

Do not wrap strap around frame of base bike, only the handle bars, otherwise turning will be a challenge.

Step 7: Tighten Everything Up Get a Friend and Go for a Ride

Tighten it all up so its nice and strong.

The heavier person usually needs to be the pilot otherwise the bike becomes too front heavy and will tip.

The pilot should always be seated before the peddler hops on.

Have fun!

My friend nicknamed this 'the make out bike', since technically you could kiss a date on this bike while you ride, but for safety purposes I don't recomend it be used in this way. Though, I do recommend asking your tandem partner to brush before riding though.