I tried both those and the sidewall clearance was too tight. I’d really like to run MTB tires, as the 45-50mm fast rolling, light knob tire options kinda suck. The 54c rubbed with the i25 hookless rims, and I was bummed. Maybe I should try a narrower rim. Can you do the hex key test for me - see whats the biggest key you can get through clean on either side?
Why are you running a Ralph in front BTW? Are you going down steep downhills? I had them flipped. The better rolling TB in front for better rolling; Ralph in the rear for better push on the slippery stuff.