Siren Bicycles will be using sliding dropouts from Ahrens Bicycles on their new product line. Check out the Trauco frameset which uses 7005 tubing throughout:
Sliding dropouts from Ahrens Bicycles serve as an alternative to eccentric bottom bracket shells for chain tensioning. Each pair comes with brass wear guides to so nothing gets damaged when the assembly is tightened. 
1/29/2007
Siren Bicycles
