the bike's frame tubing is used as the oil reservoir and cooling system The Yamaha SR400/500 uses a dry-sump design where the bike's frame tubing doubles as the oil reservoir and cooling system. Harley-Davidson has used dry-sump type lubricating oil systems in their engines since the 1930s. The Rotax engined Aprilia RSV Mille, and the Aprilia RST1000 Futura both incorporate a dry-sump, along with sister bikes, the SL1000 Falco and ETV1000 Caponord. The Honda NX650, XR500R, XR600R, XR650R and XR650L four-stroke dirt bikes utilize a dry-sump with the oil in the frame tubing. The Suzuki DR-Z400 has a 2L dry-sump with oil in the frame tubing. Chennai built Royal Enfield prior to 2007. Royal Enfield dry sump designs were completely phased out by 2012. See also Wet sump References External links Engine lubrication systems Engine technology