Eibach ERS ERS LINEAR MAIN SPRING 0600.188.0125 eBay Eibach ERS Linear Main Spring 0600.225.0575 EIBACH Aftermarket Eibach ERS Linear Main Spring (1000.300.0400S) eBay Australia ERS Main Metric Dia. 2.36 in Len: 4.72 in Rate: 1370 lbs in. Eibach's ERS line has evolved over the years to be the world's most prominent, comprehensive and superior Race Spring System. Eibach Race Springs are all manufactured in series production, often repeated, with a strong manufacturing experience. Thus, Eibach constantly achieves the most linear spring characteristic (rate) while maintaining the lowest tolerances and the highest quality in the industry.