RockShox Metric Coil Spring - Length 151mm Travel 57.5-65mm 650 lbs Black. Metric Coil springs are available in many sizes and weight ratings allowing riders to take full advantage of their shocks rebound and compression adjustments by dialing in the spring rate and setting the correct suspension sag. Coil springs are available in many sizes and weight ratings Each are available separately and are not included with aftermarket shocks