Is it finally time to change the cables?

andy83
andy83 Posts: 1,558
edited February 2009 in The workshop
I havent rode for nearly a week cos of the stupid weather but my bike is in desperate need of some maintenace. The front mech doesnt always index correctly and when the shifter is set to the biggest chainring it will move up but not move back to the middle ring unless i shift and actually push the mech across, also the cable seems really loose (hanging off the frame) so is it just a case of tigtening the cable by undoing the nut on the mech and pulling the cable through?

i have a new set of cables but not overly confident of fitting them (dont know why as i built up my bike) its prob cos im a wus and have nowhere indoors that i can work on my bike and its VERY cold

I have some shimano grease which is for bbs and hubs etc, would this be suitable to just put on the cables to protect them. dont fancy full casing cables just yet.

also my chain looks a little rusty in parts and worse for wear, is it worth replacing it or should a bit of decent lube keep me going for a few months whilst the weather is rather rubbish??

Comments

  • It sounds like your front mech needs lubrication on the joints where it pivots. There are a few of these; just apply a little oil to each of them and then move the front mech by hand several times to help the oil penetrate.

    If the cable is only loose when you try to shift from big ring to small ring, then that is because of the above. The front mech is not able to move to take up the slack. If the cable is loose when the front mech is correctly aligned on the smallest ring, then maybe you could do with tightening it a little. Many frames have adjusters on them for this purpose. Mine are just on the downtube near the top. Or do as you suggest and pull the cable slack through.

    You could grease your cables; just wipe some grease onto a rag and pull your cable through the rag. This will apply a thin layer to the cable. Some cables come with grease pre-applied.

    Your chain may have life in it yet if you clean and lube it, but beware that if it is old, it may have stretched and cause excessive wear of your cassette. You can get a tool from most LBS that will measure chain stretch.
  • andy83
    andy83 Posts: 1,558
    thanks a lot for that

    chain is not too old, less than 12 months

    just persuaded mom to let me do maintenance on bike in her house next week so in the warm lol

    i have some finish line oil i use for my chain, will this be ok??

    the adjusters are on the shifters on my bike (converted mountain bike for commuting) and the one cable casing has split so think i might just go the full hog and replace the cable whilst im at it

    thanks again
  • For gear cables (brake cables are different) I wouldn't recommend using grease as a lubricant. The pulling forces applied are smaller (in that you move the cable just a little each time you change gear as opposed to pulling it through completely as you do when you brake). This can lead to the grease 'gunking' up the cables and introducing more friction which in turn leads to sloppy gear changes (normally, seen when you change down on the rear derailleur, and thre is a delay between changing gear on the shifter and the gear actually.

    At what point is the cable loose against the frame - before or after you shift down from the large to small front chain ring?

    Suggest you give the cables a good lube - the finish line lube you have for your chain is fine. Pour some onto a rag and full the cable through the rag to coat them in lube. Make sure you do all the cable, in particular the sections normally in the cable outer sections.
  • andy83
    andy83 Posts: 1,558
    its tight when on middle ring, but is loose when i go onto the big ring and then wont move back

    looking forward to getting oil on hands again next week fixing it lol
  • andy83
    andy83 Posts: 1,558
    got out to have a play and luckily was just a build up of rubbish and after a good clean, lubrication and increasing cable tension gearing is now all fine and smooth

    cheers