I recently found myself without a Geared bike after gifting my Marin Muirwoods (to my son) and trading my Norco Indie for another Single Speed.
Fortunately, I had a Giant OCR3 road bike (collecting dust for many years because riding Drops became uncomfortable) and converted it to a flat-bar.
I guess it can be considered a Fitness Hybrid now so here it is. Happy to get it back into the Rotation!
2001 Giant OCR3 - Before

After
Parts used:
Easton 22" straight bar, ARX PRO 3T 120mm stem, Shimano BL-R550 brake levers, Ergon grips, Microshift Mezzo's,
Mavic Open Pro with 105 hubs, 105 FD/RD