# Rear shifting really hard and skipping gears



## dana109 (Jul 15, 2008)

I have a newb question. 

My rear derailleur is shifting really hard and sometimes skipping gears. When out today just on the flat surface my foot jumped off the pedal because of this. How do i make minor adjustments? Do I use the barrel by the derailleur or by the shifter? Do you just experiment with it until it's better? or is there a method?

Thank you for your help


----------



## emtnate (Feb 9, 2008)

Is your cassette and chain in good condition? Make sure the drive train is cleaned and lubed. Make sure the chain has not stretched as well. I use the park tool website as well as a couple of books when I do any repairs.

Good luck.


----------



## Kaba Klaus (Jul 20, 2005)

You are on the right track. Most likely the shifting problem is simply a problem of setting the tension of the cable right.

You can use either barrel to make the adjustment. Yes, there is a method. Go to Shimano's web site (www.shimano.com) and download the product manual for your derailleur. It includes the standard method to calibrate the derailleur.

If you like to experiment use this guidance: Focus on the barrel at the bar first. Ride. Turning the barrel in one direction will make shifting to a longer gear better, the other direction improves shifting to a shorter gear. Establish this by turning the barrel several times in one direction untile the effect is obvious. Now turn the barrel back until you reach a happy medium.

No, it is not that I don't know which direction is causing what. There are two types of derailleurs. I simply do not know if you own a top normal or low normal one.


----------



## dana109 (Jul 15, 2008)

shimano lx


----------



## The Understater (May 6, 2007)

If you find the shift lever is hard to use, then you may have dirt inside you cable housings, stopping the cable from sliding smoothly. This will adversely affect shifting and cause your gears to skip. If you shift to low gear on the rear (assuming your derailleur pulls cable to acheive low) then without spinning the rear wheel shift all the way to high gear. the derailleur will only move a bit and the cable will go slack. Then you can unhook the cable housings from their frame stops and slide them up and down the cable to see how much friction there is. It should slide really smoothly. If not, get a rag and maybe some lube and wipe as much dirt of the cable as possible, then lubricate until they slide nicely and hook them back up.
I personally use full length cable housings as they are much less prone to filling up with dirt and affecting shifting performance.

Hope this helps.


----------



## EnglishT (Apr 9, 2008)

You're on the right track - its probably cable tension which IS set on the barrel adjuster.

LX is simply a component level.. whether you have a normal or rapidrise is something we dont know. Its also important in tuning your gears up (rapidrise you start in biggest cog/lowest gear - and work down - opposite for normal mech).

As stated already - a slowness to shift (when shifting by decreasing cable tension - the one thats easier work to push) would probably be due to dirty cables/grit in the housings...

To remove the cables from their housings to clean them properly.. youre gonna need to trim off the crimpcap... so you will need dedicated cable cutters (DO NOT use pliers to cut cables, they wil fray and you wont be able to rethread them). Youll then need another crimpcap to put back on afterwards (to prevent the cleancut end from fraying later.

Did you buy the bike from your LBS? If so - they would probably do the job at a reduced rate for you... You could even ask them nicely to show you how (if you bought there, they might well help you).

_EDIT::_ When you press the shifter that INCREASES cable tension (the lever that is harder to press) - does that shift UP or DOWN a gear?
(This helps us identify the type of mech you have, and hence which cog to tune from)


----------



## xnothingpoetic (Jun 6, 2008)

This happened to me twice over the past two months so far. The second time was today. The cables are about 2 months old- so my extra adjusting might be due to the break-in/stretching on the cable. 

I always screw up and try to adjust the tension screws first- only to be pissed off as to why it is still ****ed up.

But I soon realize that there is too much play in the cable- so I tightened it (but there is such thing as too tight I learned). Problem solved.

I'm sure going to remember to check the cable first for now on.
So don't go messing with the H/L screws just yet. And don't take it to a LBS, because this will happen to you again. You will have to tweak it every now and again if you want smooth shifting. And you can't rely on a LBS in the middle of the trail. Save your money and learn to do it right.


----------



## EnglishT (Apr 9, 2008)

the H/L screws are simply the mechanical limits...


The low (on a conventional mech) will denote the rest position (when theres basically no cable tension), and the low will decide the limit of how far it can go laterally (you set it just enough to get the top cog, too much and you have potential to throw the chain over the back of the cassette).

Best way to set those, is with the cable not attached. In this case, you dont wanna touch those at all.


OP -- Look up threads about gear indexing - its all been posted many times before


----------



## The Understater (May 6, 2007)

I generally like to set my limit screws with the chain removed. Getting directly behind the mech and eye-balling the alignment. Just make sure the top jockey wheel is directly under each cog. Actually when setting up a rear mech I usually do the whole thing including setting the cable tension with the chain removed. Then I fit the chain and give another visual inspection. After that I'll ride the bike around and maybe move the barrel adjuster a couple of clicks and I'm done.
That's just my method. Others may have different advice.


----------

