Thetruvativ 4 bolt mtb chainringtruvativ 22t 4 bolt mtb bike chainring made of aluminium a super tough and long lasting inner chainring 64 mm bolt circle diameter bcd you can grace your bike with the benefits of single ring good quality long lasting ring available in hard black colour truvativ 4 bolt mtb chainring features 4 bolt chainring made of aluminium 22 tooth for 64 mm bolt circle diameter bcd a super tough and long lasting inner chainring available in hard b