The most common cause of sluggish shifting is the bits of the nice trail or road you just rode concealing themselves between cable and casing. Cleaning the bike can sometimes serve only to solidify the mud or dust so you have to be careful. Full suspension bikes suffer particularly badly – the loops of casing necessary to connect rear brake and gear cables across the central hinge are often a magnet for unwanted grit. Luckily, the cable stops on frames are slotted, allowing you to remove the casing and clean the sections of cable normally hidden within.
Pull casing forward and out of cable stop
Inspect cable and casing before you start – if either are kinked, frayed or corroded, it’s time to replace them. For gear cables, lift your back wheel off the ground. Shift into the largest sprocket front and rear, then stop pedalling. Click your shifters as if changing into the smallest sprocket and smallest chainring
For V-brake cables, squeeze the brake units together, slide back the rubber boot and release the noodle from its hanger. For mechanical disc brakes, push the actuation lever upwards, as if applying the brake. This creates slack in the cable. Follow the section of outer casing that emerges from the shifter or lever, to the cable stop on the frame. Pull the outer casing forwards and wiggle the cable out of the slot in the cable slot. Repeat at all the other cable stops. Slide the sections of casing along the cable and clean all the concealed sections (a light oil such as GT85 or WD40 works well). Re-lubricate the cable with a heavier oil – whatever you use for your chain is perfect. Slide the casings gently back into place, careful to avoid kinking the cable. Settle them back into the cable stops. For mechanical disc brakes, you need to pull the actuation lever up again to give yourself enough cable slack.
Reconnect the V-brake cable. For gear cables, lift up the back of the bike and turn the pedals around to allow the chain to find a gear. You may need to operate the brake or gear levers several times to pull the outer casing firmly back into the cable stops.
Upgrade cable kits
The standard cable set-up, with a steel cable running through a Teflon-lined casing, works well in most circumstances, as long as it’s kept clean and lubricated. But a variety of upgrade cables are available that will last longer in messier environments. The simplest solution is to use a smooth inner wire that’s been pre-coated with Teflon. These still need lubrication, but they will stay cleaner than standard cables and will reduce friction between cable and casing. They are slightly more expensive than standard cables but are no more difficult to fit.
Signed, sealed, delivered
A more extreme solution is to use a sealed cable kit – Gore-Tex cable kits are the most common example. These use a very smooth Gore-Tex coating (more commonly found as a waterproof, breathable jacket lining) on the cable. The kit comes with a plastic tube that protects the cable through its entire length. A rubber boot guards the end of the cable, stopping mud, grit or sand from creeping into the gap between cable and protective lining. The Gore- Tex coating has to be stripped off the end of the cable, so that it can be clamped securely. These sets are fiddly to set up, so follow the instructions that come with the pack carefully. Once fitted, though, the cables and casings are good quality and last much longer than standard cables. They’re worth the extra money and effort.
Source : BIKE MAINTENANCE TIPS, TRICKS & TECHNIQUES
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