How Do I Adjust Rear Derailleur
Your friend finally had enough and could take it no longer. He stated in as few words as possible that if you didn’t fix the constant ticking and “gear chatter” on your bike that he was going to ride with someone else.
This noise had been coming from your rear gears for quite awhile and you just assumed that it was normal. It was like your bike was constantly trying to change gears but never following through. The problem with this bike is that it needs to have a simple rear derailleur adjustment completed on it. Let’s learn how fixing a bike need not always be all that difficult and specifically answer the question of how do I adjust a rear derailleur?
How Do I Adjust a Rear Derailleur – Explained
The picture below shows a typical rear derailleur that you will find on most bikes.
This type of “derailleur” system allows the modern day bike to adjust the ease of pedalling to the terrain experienced. Obviously if you are starting to climb a large hill, you want to make it as easy as possible. On the other hand when you get to the top of that hill and need to come back down, you want to be in a larger gear so your feet don’t have to spin too fast.
This switching between gears is done via your rear derailleur by “derailing” your chain from one sprocket to another.
The derailleur also has another function as well. As your chain moves from sprocket to sprocket (i.e. gear to gear) its overall length must changed as well since each sprocket is a different diameter. To account for this, your derailleur is spring loaded and will act to keep constant pressure on your chain. The 2 pictures below illustrate the rear derailleur in action keeping constant pressure on the chain.
Why All the Ticking?
One of the arts to fixing a bike is to not have to fix it in the first place. Proper maintenance will allow your bike to run much longer before needing any repairs. The rear derailleur system is one such system that will need little adjustments over time because it is constantly moving and changing shape. When it does get out of alignment, your gear changing becomes tougher and noisier, mostly due to the rear derailleur not being in perfect alignment to your sprockets.
When this happens it is constantly trying to change gears but hasn’t moved enough to actually move them (thus all the noise). Let’s do some minor adjustments and eliminate all that unnecessary noise.
Simple Adjustments – That’s All
The adjustment process is as follows.
Locate the 2 little screws (see the picture below) found on the back of the derailleur which are usually labelled H and L (for high and low). Their only job is to keep the derailleur from pushing your chain completely off either side of the sprockets. The H screw controls the limit it can move inwards or towards your axle. The L screw controls the limit it can move outwards.
All you need to do is loosen the cable that moves your derailleur and then using your hand, pull and push the cable and watch the derailleur’s travel. If it looks like the travel is out of range then adjust either the H or the L screw (depending on where the travel is out). Trust me, this sounds way more confusing than it is to actually just do it.
Last But Not Least
The last step is to actually get rid of all that noise and this is done by adjusting the tension on your cable. There is a cable tension adjuster (located where your cable enters the derailleur) that only requires you to turn it either clockwise or counter clockwise. The picture below shows an example of what this adjuster looks like.
The easiest way to know which way to turn it is simply by using your ears. Have a friend lift the rear of the bike so that you can spin it in place. While spinning your chain, start to slowly turn the adjuster. You’ll know when you’ve got the proper adjustment simply by listening (noise disappears).
You Now Have Your Riding Partner Back!
A lot of the time, fixing a bike is really not all that difficult. It usually only requires some basic knowledge, with which you will be able to fix practically every minor problem that you might encounter with your bike. Now that the question of how do I adjust a rear derailleur has been answered, your noise issue would have been solved as well. You can once again call your riding partner back up and ask him to head out with you on a “quiet” ride.