Shimano Sora not shifting down gears! Please help!

galego
galego Posts: 15
edited November 2017 in Workshop
Hello,

Shimano Sora not shifting (rear) down gears.

Please see video below.

https://www.youtube.com/watch?v=n2H39xMRpJ8

Any idea what it could be?

Comments

  • arlowood
    arlowood Posts: 2,561
    Galego wrote:
    Hello,

    Shimano Sora not shifting (rear) down gears.

    Please see video below.

    https://www.youtube.com/watch?v=n2H39xMRpJ8

    Any idea what it could be?


    Bit difficult to diagnose without knowing what, if anything, is happening at the rear derailleur/cassette. From the video it looks as if the cable has either snapped, become detached at the shifter end or the rear derailleur end.

    The return spring on the derailleur provides the tension that the shifter works against so if your lever is moving all the way across as you show in the video it suggests that the cable is not attached somewhere to provide the tension needed to work the ratchet inside the shifter.

    Peel back the rubber hood and have a look to see if the cable is seated correctly in the shifter mechanism. When you swing the inner paddle across does anything happen at the derailleur? Try detaching the inner cable at the derailleur and give it a pull with some pliers to see if it is broken along its length
  • galego
    galego Posts: 15
    When you swing the inner paddle across does anything happen at the derailleur? Try detaching the inner cable at the derailleur and give it a pull with some pliers to see if it is broken along its length

    No, nothing happens. It does shift up though. If cable was broke, would I be able to shift up?
  • fat daddy
    fat daddy Posts: 2,605
    when was the last time you cleaned and lubed your gear train ?

    My bad weather bike does this every couple of months when the rear derailleur gets coated in a build up of that black road gunk or the rain has stripped everything off and needs some tlc ... basically the cable isnt pulling back through normally GT85 and some lube sorts it all out

    check the cable as well, they do this if the cable has frayed and is getting stuck
  • bbrap
    bbrap Posts: 610
    System needs a clear out. When you shift one way you are pulling the cable which exerts quite a force and thus works. Going the other way you are letting out cable and relying on spring pressure to move it which can't overcome all the crud and muck . Strip and lube and all will be well (obviously you will need to readjust after but it will be worth it).
    Rose Xeon CDX 3100, Ultegra Di2 disc (nice weather)
    Ribble Gran Fondo, Campagnolo Centaur (winter bike)
    Van Raam 'O' Pair
    Land Rover (really nasty weather :lol: )
  • galego
    galego Posts: 15
    Thanks to all for your responses.

    I had a closer look today and looks like the cable snapped inside the shifter.

    There is a guy calling to my house this Wednesday to repair it. He's charging 35eur. Seems a good price. Will try to learn this time how he does it so I could have a go myself next time.