Thanks for the question, but do you have an easier one?
The problem is that we all ask it at one time or another and have found that the range of available touring bike options is so broad that this question, the resulting information overload and then the information rich decision process can threaten to overwhelm a touring newby, noob or newb.
It certainly did me, and trying to sift through all the various options, configurations and opinions confused me to the point that one day, on a whim, I spent $1,000 on a mountain bike. Certain that would be OK, and if it wasn’t, then I would make it work.
It had two wheels, knobbly tyres and looked great.
What more did I need, it had to be perfect didn’t it?
The problem was that it didn’t turn out that way.
The gearing wasn’t right, there were not enough braze-ons and it was heavy.
But it got me the 1700 kilometres down the River Murray in 2015 and as it turned out, it was perfect for something; by spending three weeks on this bike, I discovered what I really needed in my “next bike”.
People have asked why I didn’t buy this second, more suitable bike ( a Vivente Anatolia) first and to be perfectly honest, until I had made my initial purchasing mistakes I didn’t know what I really needed. I just had to make that first exploratory move.
The lesson here is that you may well also have to make your own mistakes to work out what best suits your touring requirements. You may not get it “right” first time.
The important thing is to work out the type of touring you want to do.
Out of the following, what is going to be important to you?
How long will your tours be? A few days or a few (many) months?
What surface will you be covering: Off-road, on-road or a combination?
How fast do you want to travel? Cycling fast or slow.
How much will you need to carry? Not much (10kg+-) or a home away from home (40kg+)?
How deep is your wallet? I don’t want to spend much or the price is not a major issue?
Let your ride and budget determine the type of bike you buy and use other people’s experience and suggestions as a guide, there is no “one bike fits all” solution.
However, having said that, if you don’t mind paying a little extra, a reasonable quality off-the-shelf touring bike should be good place to start. These bikes are built to a specification that appeals to a wide range of customers who have a broad range of requirements. But if budget is an issue and you are not going far or for long, you may be better with a reasonable town bike.
Having got through all that pre-amble, if you read touring blogs, you will know that there people out there happily exploring the world on old, second-hand bikes that only cost a few hundred dollars or less.
My advice for what it is worth, buy the bike that suits you and it will in all likelihood, be perfect.
It is not what you ride, but where you ride that ultimately matters.
There is one final question you should ask, and I apologise if it offends, but “Are you likely to quite after the first weekend ride?” Do you have what it takes to be a bikepacker?
This should be a real consideration if you are going to spend thousands of dollars, yuan, peso or lempira (and you can many times over) on bike and gear. Selling it “as almost new” on Ebay will not get you your money back.