28 inch bike rim uses triathlon racing bike size 28 inches material aluminium weight 490 g size etrto 622 x 15 series mavic open tyres clincher brake mounts rim brake disc brake hubs 32 36 empfohlene reifenbreite 19 32 mm speichennippellnge 12 mm rim joint plugged ventillochgre 65 mm rim flange wear indicator fabric specification 6106 aluminium technology mavic ub control usin brut control