Internal gear cable replacement

gubber12345

The gears on my bike have internal cabling but they were pretty stiff to change especially the front one so decided to change inner and outer cable on it.

Got the job done without any major trouble but instead of the shifting being nice and slick as I expected it,it seems to have gone the other way and is now worse...everything is as it should be as far as I can tell,is there anything I may have missed?

TIA

cougie

Are the cable ends back in the holders on the frame ? Make sure they're all the way in.

StillGoing

What bike is it and is it the rear, front or both derailleurs?

Are the shifters operating freely. Are the derailleurs moving freely. If yes to both. Hold the end of the cable inner in one hand and try the shifters to see if they still operate freely. If they do, maybe the cable routing isn't following the correct course through the frame. If the shifters don't operate freely, have you threaded the cable inner into the shifter correctly? SRAM shifters for example have a number of apertures and easily get confused if you don't pay attention.

gubber12345

cougie wrote:

Are the cable ends back in the holders on the frame ? Make sure they're all the way in.

Yeah..made sure to push them in properly....even after a short test ride everything seems in place.

gubber12345

philthy3 wrote:

What bike is it and is it the rear, front or both derailleurs?

Are the shifters operating freely. Are the derailleurs moving freely. If yes to both. Hold the end of the cable inner in one hand and try the shifters to see if they still operate freely. If they do, maybe the cable routing isn't following the correct course through the frame. If the shifters don't operate freely, have you threaded the cable inner into the shifter correctly? SRAM shifters for example have a number of apertures and easily get confused if you don't pay attention.

Just did the front at the minute didn't want to do the rear til I get this sorted.will try tor row and release the cable and try the shifter and see if it is running free...pretty sure it's ok tbh.
Only thing I can prob think of is as you suggested maybe the cable has twisted round the rear cable..just have 105 group set on a Merida 904 so the routing looks pretty easy although I couldn't use the sheath that comes with the cables as it wouldn't pass through the eyes on the frame leading into the tube.

StillGoing

gubber12345 wrote:

Just did the front at the minute didn't want to do the rear til I get this sorted.will try tor row and release the cable and try the shifter and see if it is running free...pretty sure it's ok tbh.
Only thing I can prob think of is as you suggested maybe the cable has twisted round the rear cable..just have 105 group set on a Merida 904 so the routing looks pretty easy although I couldn't use the sheath that comes with the cables as it wouldn't pass through the eyes on the frame leading into the tube.

A Merida 904 should be dead simple. The front being 105 should shift easily. You don't need to apply lots of pre-tension when securing the cable to the derailleur clamp, but you do need an in line cable tensioner. Maybe you have too tight a turn in the cable at the bars? There should also be a sheath over the cable inner where the cable inner exits from the bottom bracket position up to the front derailleur. The rear should be a continuous length of cable outer from shifter to rear derailleur, so shouldn't be any problems the rear.

Nick Payne

philthy3 wrote:

There should also be a sheath over the cable inner where the cable inner exits from the bottom bracket position up to the front derailleur.

I have found in the past that this sheath where the cable inner exits behind the bottom bracket can be the cause of the front shifting being very stiff. Every time you ride in the rain, some of the crap that comes off the tyre will go down the inside of this sheath, and over time the inner cable starts to bind at this point. I've serviced bikes where this piece of tubing was so full of crap that the new gear cable couldn't be pushed through it.

These days I replace the sheath at the same time I replace the inner cable, and I also cut a small length of heat-shrink tubing that is a sliding fit over the sheath, and heat the top of the heat-shrink so that it shrinks around the inner. This acts as a boot to prevent the grunge that comes off the tyre from getting in.