Cable friction is one of the leading causes of sluggish shifting. To lubricate your cables, simply apply a Teflon based lubricant to any exposed cable where it enters into a cable housing. Good access points for lubrication are often located at the shift lever, where the cables enter the derailleurs and under the bottom bracket (where the cables are routed on many bikes) . After applying the lube, work it into the housing by pedaling and shifting the bike. Lubricating the pivoting sections of the derailleur itself, as well as up in the shift lever housing, is also a good idea. Unless you don’t care to stop when using your brakes, use care to keep all lubricant away from the brake pads or the braking surface of the rims.