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Shimano Gears won't shift

billsk8billsk8 Posts: 2
edited May 2015 in Workshop
Basically when pushing the button to shift gear I can only get one speed up and one speed down. I tried adjusting derailer and the tightness on cables but it makes no difference.

Figured I'd make a video to explain it better here you go.

https://www.youtube.com/watch?v=N86AkyA7gn4

thanks and ask questions if needed

Posts

  • First.AspectFirst.Aspect Posts: 5,423
    Still none the wiser I'm afraid.

    Is your problem that you can only change gear one at a time?

    Or is your problem that no matter how many times you try to change gear, it will only move by one?
  • cswitchcswitch Posts: 261
    cable might be snapped / frayed.
  • arlowoodarlowood Posts: 2,501
    Operating the shifters with the rear wheel static does not help to elucidate where your problems lie.

    Would have been better to have the bike on a stand and turned the pedals while you moved the thumb button and/or the brake lever shifter. That would then have shown us what the rear derailleur was doing in response to the actions at the handlebar end.

    Can you explain or film what happens to the derailleur. That would help.
  • OuijaOuija Posts: 1,386
    Process of elimination. Ignore the shifters and simply yank on the bare bit of cable nearest the back of the bike and see how far up or down the cassette you can get the derailleur to go when turning the cranks.

    If you can get it all the way up and down the cassette it's a shifter/cable tension problem.

    If it doesn't move more than one or two positions it's a derailleur problem.

    If it's the derailleur, unscrew the two bolts on the back of the derailleur as far as you can and try the above test again (by pulling the cable yourself, not with the shifters). If it still doesn't work your derailleur probably needs replacing.

    If the derailleur seems to be working fine doing this test then move your attention to the shifters. Unclamp the cable from the derailleur and set the shifters to their lowest tension setting (press the thumb lever as many times as you can). Pull the cable tight through the derailleur and reclamp it. Now start going through the gears with the brake/gear lever and see how many you can get. If the first click doesn't do anything, don't worry, that's just because there isn't enough tension in the cable yet (use the inline or back of derailleur adjuster to add a bit more tension)

    If the shifter still refuses to move up more than one gear then your shifter is jammed or broken.
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