The Impossible Hybrid

[Coalfield]

It seems to me that rigid mtn bikes would come very close to meeting your needs. Maybe a change of handlebars? Tires without knobs?

You have one = What am I missing?
OK, maybe not every rigid mtn bike fits the need. But upright riding position, shifters on h'bars, slack angles, etc.

 

[bikeworkshop]

It seems to me that rigid mtn bikes would come very close to meeting your needs. Maybe a change of handlebars? Tires without knobs?

You have one = What am I missing?
OK, maybe not every rigid mtn bike fits the need. But upright riding position, shifters on h'bars, slack angles, etc.

But the bigger wheel of a hybrid rolls nicer on decent ground.
Frame geometry up to mid 90s was very similar.

 

[Woz]

At one point in time if you went in a bike shop and didn't want a DH monster or road bike you got pulled aside to the unlit corner to eye over 3 sad pathetic Hybrids. All some generic AL crap and sporting the worst generic toss with low end gruppos.

AFAIK, Bridgestone, Breezer, Marin, and Gary Fisher all had good Hybrids that may be easier to find in your parts.

 

[Woz]

Consider to turn it all around. Get a more available good tourer / CX and slap some flat-bars on.

[ there would potentially be other considerations to take in account, but all feasible ]

 

[Coalfield]

I think the issue of 'rolls better' for 622 ETRTO over 559 is 'generally' true. And may feel more natural to tall guys seeking XL.

However, I would submit that tires and gearing are not to be underestimated when making comparisons. The smaller diameter rim can be more responsive in tight conditions, potentially a stiffer wheel and still offers tyre widths from 1" - 2.3", including options with 'supple' sidewalls (casing).

My real world experience with Hybrids may be limited because ... I fail to understand the distinguishing features that matter most to a hybrid buyer. Maybe they existed shortly, according to OP (though I might challenge that opinion), because the term is so nebulous. Flatbar tourer? Multi-purpose City bike? Errand runner? Off-road capable to some extent? Low gears for easy on hills?

I do not ride off-pavent often - every time I think about a drop bar conversion for my 1991 GaryFisher = can't pull the trigger. It has had narrow Tom Richey slick tyres that measured ~30mm, Kenda 1.75" (~44mm), and presently Schwalbe 2.1" (54mm). And what a huge difference each makes. It is the largest frame SuperCaliber in '91. 71° HTA makes sure it is not overly quick handling at slow speeds, and 42cm chainstays keep it nimble for maneuvering/stiff for accelerating. Handlebars/stem can be changed to suit one's best position/use.
Here is an example of versatility - maybe lacking enough eyelets for some. Last pic shows inner 'bar ends' allowing vertical wrists and narrow position for pavement or hardpacked trails.

 

[winjohn]

I have had a couple of Marin San Rafaels which were great bikes and very cheap, £25 I seem to recall. I serviced them and sold them on to friends' kids as university hacks and they did the job really well.
The only bike I have atm that fits that niche is a Falcon Carmargue with a 501 frame and I am not sure if that was originally a drop bar that has been converted many years before i got it.