Fixing frayed ends
The most common cable issue is fraying. Usually what happens is that the cable crimp comes off (or there wasn’t one) and the end of the cable starts unwinding and frays. Because this part of the cable isn’t doing any work, it’s rarely a problem, but it does look unsightly and, worse, the individual strands can easily stab you if you run your finger into them.
To fix this, grip the cable below the fraying with pliers and turn them in the same direction the cable is wound as you pull them toward the end of cable. This presses and twists the individual strands back into place. Crimp on an end and your cable will look great and be safe too.
Make it easy to get broken cables out
When shift cables break inside the shift lever, it can be a pain getting the end of the cable out of the lever. To make the cable less likely to break in the first place and easier to get out if it does, be sure to put plenty of lube on the cable head and a portion of cable inside the lever.
Most bicycles have brake cables that don’t need frequent lubrication because they’re inside fairly well-sealed housing, with a slippery nylon liner inside. But shift cables are usually exposed and can become gunked-up with dried energy drink, or can simply get dry or even rusty. You’ll usually feel this in sluggish shifting and increased shifting effort.
The cure is to regularly check your shift cables and keep them clean and lubed. Energy drink usually runs down the cables and collects on them at the bottom bracket guides beneath the frame. Use hot water to clean it off, and lubricate the cables there with grease.
Also, inspect the cable where it enters and exits the short housing section leading to the rear derailleur. On many bikes the housing stop on the chainstay is split. This allows you to create slack in the cable and then lift the housing section out of the stop. You can then slide it along the cable to apply grease to the section of cable that was hidden to make your shifting smooth and fast again.
I just spotted this in Shimano’s Dealer News and had to pass it on. I haven’t even had time to try it. It’s a trick from Huber Rodriguez, a Shimano Tech Rep out of Fort Worth, Texas. Huber says, “Pack a housing ferrule (the metal or plastic housing cap) with Shimano’s Special Grease SP-41, then insert the housing section into the ferrule. Now attach a floor pump to the ferrule and use it to blow the grease into the housing. Do this procedure twice to each piece of housing.” I’m looking forward to trying this when I install new cables.
No need to double tape
This tip saves a little time, a tiny bit of weight and makes for a cleaner handlebar taping job. When setting up a new bicycle, it’s common practice to tape the cables to the handlebars with electrical tape to keep them in place as you wrap the bars. With just a little extra effort, though, you can easily hold the cables where they need to be as you wrap your bars and just let the bar tape hold them in place.
Diagonal cutters work fine
You can spend a lot of money on bicycle cable cutters, special cutting pliers that have diamond shaped jaws to prevent fraying cables and smashing housings when sizing them. These are nice tools. But if you don’t have one, quality regular diagonal cutters will work fine. They have to be high quality with sharp jaws. I recommend Channel Lock’s #337, about $20.
Cutting housing the easy way
Even with special cable cutting pliers, it’s easy to squash the end of the housing. You then have to use an awl to open the end and sometimes trim it a bit. An easy, simple way to cut housing clean every time is to save pieces of cables you’ve cut. Then insert a piece into the housing before you make your cut. The cable will prevent the housing from getting crushed, and when you extract the cable piece, you’ll have a perfect cut the first time, every time.
A routing trick to prevent paint damage and cable rattle
On bikes with shift cables that aren’t hidden beneath the handlebar tape, two common problems include the housing sections hitting each other, rattling and driving you crazy, and housing that rubs against the head tube, eventually wearing through the paint or even your frame material!
A trick that can prevent both problems is criss-crossing the shift cables and housing. To do this, route the rear-derailleur cable to the leftmost frame stop and the front-derailleur cable to the right. As you do this, criss-cross the housings so that they’re wrapped around each other once. Now, to get the cables routed correctly, criss-cross them beneath the down tube so that they follow the correct path to the front and rear derailleur. When done, the housings will be held in place by each other and won’t rattle. And when you turn the bars the housing will move away from the frame and be unlikely to rub and wear the head tube.