Schwalbe marathon plus 27 5 tyre smartguardthe new flat less tyre after 10 years we have thoroughly overhauled the marathon plus the only true flat less tyre gets a new dynamic profile and boasts many internal improvements rolling resistance the patented 5mm thick smartguard layer when compared to all generic products has a significant advantage in rolling resistance we further extended its lead in the latest version recycling also in the smartguard we now use a proportion of rec