Howdy! Are you running the TCS Tough or TCS Light version? The more supportive of the TCS Tough casing allows me to run considerable lower pressures than the TCS Light version. On my Surly Krampus, with 29 x 3.0 TCS Tough Rangers on a rim with a 45mm inner rim width, I feel comfortable running 12 psi. I’d say 15+ with the TCS Light version.