Thanks, that's a lot of empty space. From the photo it looks like that's the Explorer 29er (disc) which would be taller than the Explorer (disc) or the (adjustable) Uni Explorer (disc) models. See
https://www.topeak.com/us/en/products/91-Racks for the various options.
If you can get me the measurement from the rack mounting hole near the axle to the top of the tire, I'll check against my Explorer (disc). I have nothing like that amount of empty space on my 700x38c hybrid and my seat sits higher. It'll be a couple days though until I return to where my hybrid is right now.
If you're near an REI it might be worth ordering/buying one of the racks from them so you can truly hold it up against your bike and see how it seems to fit.
(I don't do the rolling dismount stuff these days; I'll just stop, tilt the bike, and swing my leg over.)
Edit - also you might consider a rear rack seat post collar rather than the pictured spot on the seat stays if there's a way to raise the bottom of the dropper post enough or mount to the actual seat tube.
Add a rack to your frame, even if you don’t have rack mounts. Allows standard rack stays to be bolted directly to the seat collar, for a clean and simpl...
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