My Tallboy has 27.5 x 2.8 Maxxis Ikons - a fantastic tire for the Central Texas chunk. Noticeably slower on the asphalt! When connecting on the Southies, or a short push up 360 after a Greenbelt excursion, it’s a beat down to keep up with those slimmer tires. Funniest thing is, belting down Hwy 50 to Poncha Springs after Monarch Crest, I actually hit ‘hull speed’ - about at 45 mph. I can’t pedal to push the bike, and it will not accelerate downhill on its own.