27.5" wheel, 1.5" hub, heavy duty spokes

Just what the bike world needs, another uncommon wheel size.

26 inchers are 559mm (ISO size), 27.5 inch is 584mm, 700c/29 inchers are 622mm.

There's definitely a larger/cheaper selection of 26" (559mm) rims and tires. If your brakes will reach the rim (if you use rim brakes), then that would probably be the best swap. 622mm rims/tires come in a wide variety, but go under a lot of different names for different widths. Road rims, cyclo, hybrid, 29er. All 622mm tire diameter. Stupid naming system. If you search many bikes sites, you may have to search all these separate categories to see if they have the rim/tire you want.

Again, check if that size will work with your brakes and fit within your frame and forks.

I would get rid of the 27.5 crap in a heartbeat, but it's a matter of preference.