The x king performance 29er folding mountain bike tyre fills the gap between the race king and mountain king ii it is super fast yet extremely grippy and the x king was developed in conjunction with the topeak ergon mtb pro team along with the basic versions in 22 and 24 widths here is a tyre to get you up and down any terrain you may come across the performance version of the x king is folding and has contis pure grip compound which gives you a longer lasting more durable grip