Wogster

So why can't you downshift?

There are one of five reasons.....

1) Everything is way out of adjustment
2) The cable needs to be lubed or replaced.
3) The Dérailleur is pooched
4) The Shifter is pooched
5) Two or more of the above.

First thing is to determine what is wrong.



Put the shifter in the lowest gear, put you thumb against the cable, now shift to the highest gear, the cable will either be tighter or looser, if it's about the same, the shifter is probably not working correctly. Spray some WD-40 into the shifter mechanism, use lots, see if you can un-stick the mechanism. If you can, then that may be all it needs, but we will do some more.

Get some bicycle oil and degreaser, and a can of WD-40, with the little straw nozzle on it, and a new dérailleur cable. You need a good pair of cable cutters, nice and sharp ones Now look at the rear dérailleur loosen where the cable is attached to it, pull the cable off. Pull the cable back through the housing bits, keep them in order. As you pull the cable out of a housing section, flush it with WD-40.
Then pull it out of the shifter, look at the old cable, is there any rust on it, loose bits or kinks in the cable, if any of these questions are true, then you need to replace it. Take the new cable, one end will look the same, the other looks different, cut off the one that looks different.

Take the derailleur and push it side to side, with the bike upside down, so you can pedal with your hand, push the derailleur all the way so that it lines up with the large sprocket, if it doesn't want to move, then spray the pivot points with the WD-40, and work it back and forth until it moves easily. Let go, most deraiileurs will go to under the largest cog at the back, I'm assuming that is the case, if not, then reverse what I am about to write.

Hold the derailleur so that it's over the largest sprocket, and hold it there, turn one of the screws, you should see it move slightly, if it doesn't rtry the other one with one of them, if it does, that's the one, turn it so that the derailleur moves towards the wheel until the chain rattle slightly, then turn it back 1/4 turn. Now let the derailleur go, it should spring under the largest sprocket, Turn the other screw, so that it moves away from the wheel, until you get a rattle, and again, back 1/2 turn. Now there should be an adjusting barrel the cable goes through, turn this so that it gets shorter, until you get to the shortest position, then turn it back 1/2 turn.

Now taking your new or good old cable, put some oil on your fingers and run them along the cable, then through a rag to take off the excess. Feed it back through the shifter, and along it's path, through the cable housing as needed, then through the cable adjuster, and through to where it attaches to the deraillaur, make sure the shifter is in the same position as the derailleur us normally in. This will be the lowest if it's under the largest cog, highest if under the smallest.

feed the cable through the shifter, then back along it's original path, through the housing through the adjusting barrel, and to the point where it attaches, hold it taught but not tight, and tighten up the bolt holding it, as tight as you can. Now with the bike right side up, move the shifter through it's range while pedalling with your hand with the back wheel lifted up. if the chain rattles turn the adjusting barrel 1/4 turn, if it still rattles, another 1/4 turn. At some point it will shift between all of the gears quietly.

Go for a short ride, and see if that fixed it, you may need to make more adjustments, and if it starts rattling again, then you need to turn the adjusting barrel 1/4 turn.










Feed the cable through the shifter, and back through the housing bits. Before you feed it through a housing bit, put some WD-40 along the inside.