The gang is joined by Mason from Sportster Parts Swapper on Instagram @sportsterpartsswapper. We talk about tire ratings, psi, and what all those numbers really mean. We answer a question from our Gnar Talk Hotline answering machine, about putting an open primary on a Twin Cam. And we ask our listeners for feedback about their gear ratios on 74" Shovelhead at highway speeds. Song of the Week by Fly Anakin; Backyard Boogie.