Front wheel bike wheel system uses racing bike triathlon size 28 inches size etrto 622 x 15 series mavic ksyrium weight 675 g tyres clincher brake mount rim brake spoke type bladed spokes hub 18 spoke material stainless steel fitting dimensions front wheel 9 x 100 mm lacing radial front rim joint welded rim flange parallel type of bearing industrial technologies mavic fore mavic isopulse fabric specification mavic maxtal