Preventing energy dispersion is possible with the velocetm chain power transmission is assured the hd linktm system protects you from any risk of the chain not keeping traction at the delicate closure point silence and fluidity of pedalling are achieved by the perfect machining of the link profile technical specifications width 5 9 mm ni ptfe finish 114 links ultra drivetm requires hdlinktm for ultra narrowtm chain weight 2 39link