Single touring using tandem , WHY NOT ??

Seems like the problem with light wheels, front panniers and short wheelbase of the classic diamond bike can be solved by the tandem frame. It is much longer, have heavy duty wheels etc. I am planning on building hybrid , or 1 1/2 long frame with two seat tubes and two bottom brackets , rear bottom bracket will be used for stand. Front wheel will be 36 hole rims with dynamo/brake hub, rear wheel will be 48 heavy duty spokes soldered. Frame will have 5 couplings for easy disassembling, instead of panniers I will have braze ons for two , airline 62 linear inches legal size aluminum cases.

I've seen a great big four wheeler normally powered by four people pedaling, why not go the whole hog & use one of those?

Uh, what am I missing here?
Why would you want to carry the weight of an extra crankset, saddle, bars, etc. if you are riding solo?
If you want a long wheelbase, just get a Surly Big Dummy or any other cargo bike.

who needs extra crankset, saddle , bars , etc. ???
1 and 1/2 longer frame will need only 1 and 1/2 longer chain
i would like to have LONGER wheelbase than Surly

Sound a bit like you are trying to create an Xtracycle? https://www.xtracycle.com/

^ I liked the "Long John" - "steers like a boat." + 1 to that manufacturer for honesty.

OP, this might sound crazy, but couldn't you just make a custom built trailer that would allow your bike to be more maneuverable and save weight? If you have the mechanical skills to build that tandem frankenstein I'm guessing you could build one heck of an aluminum trailer.

I'm presupposing here you only want the longer wheelbase on the bike for cargo carrying capacity, though. Maybe you just want a bike that handles like a pig on roller skates.

well, everybody is PROPOSING same old same old SOLUTIONS
I do not want trailer ( extra wheel, extra weight, extra volume)
I do not want to have anything weighting down front wheel

The idea is to have TWO hard cases with 62 linear inches for air travel)
secure them to the frame in lieu of panniers ( that is why the long wheel base)
Frame also will have to withstand extra weight of water for stealth camping , multi fuel stove with large tank , to avoid frequent refueling

yes and no

xtracycle is just "adaptor" or extension for regular bike with regular diamond geometry

Well since you've made up your mind, OP, why are you asking people's opinions?

Please do not get offended

well
I need a good argument WHY NOT
but not the same solutions from the past

from my perspective having double purpose hard case air travel / panniers is very valuable feature
light load on front wheel is great for steering
second bottom bracket is ideal for steady kick stand
extra length translate to larger volume behind pedals and space for water etc

You can tour on anything, including a tandem with one person. However, the question is, why? You can always put heavy duty tires on a regular bike, you don't need front panniers (I've never used them), and I don't see where a "shorter" wheelbase has anything to do with touring. And if you have to get repairs on such a modified bike, you might have problems getting someone to fix it for you.

What you need more than anything else is a bike that feels comfortable to day after day after day....

From the sounds of things - not quite a tandem since its not intended for two riders. More like a custom bike using a stretched frame. Could be interesting!

Sounds crazy to me, but I'm not going to be the one pushing the pedals, so who cares what I think. Post up some pictures when you are done.

more or less

how crazy ???

crazy hahahaha
or crazy hihihihihi

WHY NOT use longer bike and save front ???

well
what do you do in far away land with your two
air line traveling cases 26X26X10 ???
and why do You need panniers there
when you have to dispose hard cases
which were used to transport panniers

For anything above very low speeds, bicycles turn by leaning the whole frame. The cyclist starts the lean by trying to turn the bars in the opposite direction from the intended turn, in response, the whole bike leans in the opposite direction. Put an experienced cyclist on an off-road trike for the very first time, and his reflexes will be all wrong in turns, and he may crash (speaking from experience here!)

Basically a load on the front wheel just makes it harder to steer at very low speeds

sounds a bit eclectic,think i understand the concept - op wants to be fully self supported includingbike transport luggage. i've cycled solo on our tandem a few times - not the best balanced rides. the stretched frame concept makes more sense in terms of bike handling and performance. the only serious why not ? weight - the fully loaded bike and stuff would be pretty heavy - it would be a beast to slog up hill or into a wind.

You'll figure out why not when you try touring with the thing. A good rule of thumb is that everyone else is not stupid.

First of all, I don't oppose your idea. Build it. As far as "why not" here's all I've got:

1. You need to keep the rear wheel weighted on a tandem. Otherwise, when you apply your front brakes, your rear end will literally fly by you in mid-air. I know you are intending to keep all your gear over the rear wheels, but that may not be enough if you don't have great braking skills when the feces hit the blades on a steep descent. (Hint: if the rear wheel is losing traction, the front brake is working too hard.) You are also giving up the technique of getting your bum behind the saddle to increase rear wheel load for improved braking.

2. It sounds like you are going for a heavy rig. In my neck of the woods (Pacific Coast), speed equals safety. Dragging extra pounds up hills means having more motorists pass which increases the odds of winning the lottery. If you're riding where that's not an issue, have at it. Besides, lots of slow riders tour here and we only have a handful of lottery winners each year.

sure

WHY NOT ??
weight ??
how many #s
is extra seat tube & bottom bracket & half top tube & half down tube & 50% more chain

thanx

PS - the contraption won't be full tandem size

I used to commute (solo) on my tandem. It's a really great bike for solo use, very solid and dependable. The only thing is, if someone yells, "you forgot somebody" one more time I might try to kill them

That certainly hasn't been my experience in many miles of riding our tandem solo without any extra weight on the rear of the bike. The tandem used to be our commute vehicle so if I ever needed to go somewhere during the day I'd hop on the tandem by myself. Applying the rear brake could be an issue since it would skid rather easily with the light load on that wheel, but using the front brake was never an issue. Also used the tandem to climb some particularly steep (but fairly short) hills since the low gearing on the tandem let me pedal up them whereas I'd be forced to walk on my solo road bike. Definitely had to use the front brake a lot on the way down - but again, it was never an issue and the tandem handled fine (although a bit truck-like) when ridden solo.

To the OP:
I know it's been done before since I remember reading an article about someone setting out on a long (round the world?) tour who was choosing to use a tandem for its ability to carry lots of luggage within the long wheelbase. But I wouldn't choose to use your proposed design. For one thing the extra weight burden seems excessive - the tandem itself probably adds 15 or more pounds compared to an equivalent solo bike, the large number of couplers add some more pounds, and the two hard cases plus packing material add still more. So you're probably at least 50 lbs. over the typical bike tourer.

And then there's the bulk of the package you're proposing. A tandem is trouble enough to transport, but consider if you ever find the need to hitch a ride or take public transit with a tandem plus two full-size suitcases (yes you could do the disassembly and packing - but in my experience with other's coupled bikes that's a rather lengthy procedure - and you still have two big and heavy pieces of luggage to deal with plus whatever you now have to carry the rest of your gear).

An alternative to fully self-contained touring incl. airline luggage would be Bike Friday's system using a folding bike that tows a trailer frame on which you carry a regular Samsonite suitcase with your gear inside. Ride to the airport and the bike and trailer frame fit inside the suitcase after you take out the gear and pack it in your carry-on duffel. That way you only have one big suitcase, the bike packs more quickly (and folds enough for transit systems in only a few seconds), and the trailer disconnects quickly leaving you with a nice riding and maneuverable bike for city sightseeing when you stop somewhere for a day or two. Or, if you really don't want a trailer then something like a Big Dummy gets you the long wheelbase and luggage carrying capacity but without going all the way to a tandem length and weight.

It sounds like you want one of Avorn Cycles touring longtails.