Morning all…I need to sort my shifting out. My gears are constantly skipping up and down at the back. What’s the correct order of doing things to fix this?
Thanks

You need to set up your gears. I think the Park website has good video guides.

You may have a worn dérailleur or sticky cables also.

providing the chain and/or cassette aren’t knackered it’s just a case of setting the cable tension.

have a look here, it’s alot quicker than me typing it all out!

http://bicycletutor.com/adjust-rear-derailleur/

I suppose that the first question is how old is everything? You may be looking at replacing stuff. You can try a quick fix by indexing the gears. There is plenty of stuff online about this, google the Park Tools website or Sheldon Brown. It is something you can definitely try yourself and is very satisfying when you fix it.

HTH

Hi all….everything is fairly new. Chain is at 0.5 on the wear tool so I’ll just try cable tension and failing that clean the cable.
I just wondered how little i could get away with.

Thanks for the advice

I found the above mentioned (sheldon brown) sire useful. http://www.sheldonbrown.com/derailer-adjustment.html

First time I had gears skipping I just followed his advice for Indexing Adjustment and hey presto.

From that site…

Indexing adjustment
The indexing adjustment is the most frequently needed derailer adjustment. The detents (click-stops) that provide indexing are in the shifters, and the index adjustment sets the length of the cable so that the derailer is in the correct place to correspond with each click stop.
If a derailer is correctly adjusted when it is installed, this is the only adjustment that should have to be tweaked later on, to accommodate cable stretch, or when cables are replaced.

The indexing adjustment is an adjusting barrel located at one end of a length of cable housing. Many rear derailers have more than one index adjuster. All indexed derailers have an adjuster where the final loop of cable housing ends at the derailer itself. Many bicycles also have another adjusting barrel located so that it can be adjusted while you are riding. On mountain-bike-type shifters, this will be located at the shifter itself, just where the cable exits. On road bikes with handlebar-mounted shifters, there will usually be an adjusting barrel at the cable stop where the upper length of housing ends on the upper end of the down tube.

It doesn’t matter which of these adjustments you use, use whichever is more convenient.

Before you try adjusting the indexing, shift to the highest gear (smallest sprocket.) Make sure that the shifter is in the position that allows the cable to be as loose as it can get.

Click the shifter to the first click after the fully loose position, then turn the pedals forward. The chain should shift to the second smallest sprocket. If it doesn’t, it means the cable is too loose. Turn an adjusting barrel counter-clockwise to tighten the cable. Start with half a turn, then check again. It is very common for beginners to over-correct by turning the adjuster too far. Sometimes this will result in moving the indexing so far off that it sort-of works, except that the clicks are one notch off, so one of the extreme gears doesn’t work properly, but the others appear to be OK. This is why it is important to check that the shift from the smallest to the second-smallest sprocket occurs in the right place on the shifter.

Fine adjustments are accomplished according to the following principles:

Shifting to larger sprockets is accomplished by tightening the cable;
if such shifts are slow, the cable is not tight enough–
turn the barrel counterclockwise to tighten it.
Shifting to smaller sprockets is accomplished by loosening the cable;
if such shifts are too slow, the cable is not loose enough–
turn the barrel clockwise to loosen it.
If the rear indexing works properly when using the large chainwheel but not on the small chainwheel, or vice-versa, this is often a sign that the rear derailer hanger is bent.

If it’s constantly clicking and shifting up and down, it suggests to me that your tension adjustment is not quite right. My usual drill is to shift onto the smallest sprocket which relaxes the cable. Put a couple of turns on the fine-adjuster; it’s usually up at the shifters. Gently release the cable-grab nut at the derailler and pull the cable taught then re-tighten the nut. Then spin the pedals and shift up and down the block a few times to make sure it shifts one sprocket with each click. Fiddle with the fine adjuster. If this doesn’t help, it’s worth investigating the cable. If it gets dirt in it, it can get sticky so that it doesn’t consistently shift. The final section of cable outer is the worst offender. Rusty cable-inner is another culprit. Just replace the whole thing.

Consider also that the derailleur hanger (or frame) may be damaged.

Most shifting issues can be sorted with a new cable. Even cleaning and relubing an old one doesnt seem to be as good as new inner and outer set. Make sure the outers are cut square with no burrs and the inner plastic tube is not crushed. If that doesnt sort it then start checking for wear in the chain and sprockets, hanger alignment etc.