cant shift into lowest gear

frosty99
frosty99 Posts: 115
edited November 2011 in Workshop
Noticed two problems on a ride today, I think (but cant be sure) they came on after I fixed a puncture so may have knocked something putting the rear wheel on.

1) going up a hill i couldnt stay in my lowest (biggest) sprocket, i could just about force the derailleur onto it but a few pedal strokes later the chain would slip back to the second biggest.

2) When in my large chainring the cage is rubbing on the chain unless i keep pushing the shifter across and hold it there while I pedal.


I wondered if the two problems could be the same thing. I have tried loosening the lower limit screw on the rear derailleur, this had no effect when i unscrewed it 2 full turns so i put it back to where it was.

any ideas??
thanks alot
Frosty

Comments

  • dabber
    dabber Posts: 1,937
    As this has occurred after you having had the rear wheel out for a puncture repair I suspect the problem is that you haven't reseated the wheel properly in the dropouts. With the bike upright, release the QR and push down on the rear of the frame and make sure the wheel is seated correctly before retightening the QR.
    “You may think that; I couldn’t possibly comment!”

    Wilier Cento Uno SR/Wilier Mortirolo/Specialized Roubaix Comp/Kona Hei Hei/Calibre Bossnut
  • frosty99
    frosty99 Posts: 115
    thanks Dabber, just tried that, to no avail, it seemed it was seated well in the dropouts and certainly is now but still no good!
  • Three things are needed for your bike to shift to the biggest cog in the back and stay there:

    1. The derailleur hanger needs to be straight. Check and make sure your derailleur hanger and derailleur haven't been bent out of shape due to a crash or such. And as previously mentioned that the wheel is seated in the dropouts correctly (and cassette lockring is tight on the freehub).

    2. The lower limit screw on the rear derailleur needs to be set correctly.

    3. The rear derailleur cable needs to have sufficient tension. If it does not, turn the barrel adjuster counterclockwise in 1/8-turn increments until the chain can shift to the biggest cog and stay there.

    Pretty simple, really.
  • frosty99
    frosty99 Posts: 115
    Thanks LongIslandTom. Cable was the problem!! The RD doesnt look bent and the stop screw wasn't the issue. I turned the cable barrel adjuster anti-clockwise 2 turns and this solved the problem!!

    Thanks alot
    Frosty