Alas, the selection of tires available for the 650C size was miniscule in 2015, and may be less than miniscule now, and those available were mostly 23 mm models, tho' I think Terry made a rather heavy 28 mm model. Tho' the selection of good road-capable 559 tires is small, it's a heckofalot bigger than that for 571.
There's only about 1/4" radial difference between 559 and 571 sizes: my 650C wheels with 23 mm Pro Races measured about 24.5" in diameter, my 559 wheels with 23 mm Turbos measured 24" in diameter. Past tense for both.
Patrick Moore, who still has a small stash of Sun ME14A 650C rims waiting for the time when BQ introduces its full line of 571 tires, from 26 mm to 60 mm in smooth and knobby models.
And, yes, that bar. So, so many things wrong. (But if the rider found it the best solution to needs, and this is not merely a desperate attempt to make an unrideable bike rideble, more power to him/her.)