How to Adjust a Shimano 21 Speed
If you want to calculate the total number of speeds or gears on your bicycles, you can do that by simply multiplying the rear cogs of your bike with the number of front chain rings. Normally, a bicycle can have more than 21 speeds as there are seven rear cogs and three front chain rings. However, if you want these gears to work, you have to properly adjust each derailleur cable. Each of these gears rely heavily on the Shimano brand derailleur.
Rather than spending money on adjusting it, you can do it on your own if you have a five millimetre Allen wrench and needle nose pliers.
Instructions
-
1
The first thing that you need to do in order to adjust the Shimano 21 speed bicycle is by adjusting the rear derailleur. In order to do that, you will require a five mm Allen wrench which will loosen the anchor bolt. Once you have managed to loosen the anchor, you can take the next step.
-
2
Now, pull the cable right through the anchor until it is tight. As soon as you are able to tighten the anchor, you can easily tighten the anchor belt.
-
3
The third step will be adjusting the front derailleur. You can adjust derailleur the same way you adjusted the front one. Rather than loosening the anchor, you will change the front gears to the lowest one. Once you have done this, you can easily adjust the front derailleur the same way you did the rear one.
-
4
However, in order to adjust the front derailleur, you will first need to shift the largest rear cog and then the smallest front chain ring. When you do that, the chain will be in the innermost gear combination.
-
5
Using the 5mm Allen wrench, you can further loosen the front derailleur cable that bolts the anchor. You will be able to find the anchor bolt just above the derailleur which is on top of the front chain rings.
-
6
Bear in mind that the front derailleur barrel adjuster of a Shimano 21 speed mountain bike can be found where the whole cable enters the body of the shifter.
-
7
Using the needle nose pliers, you can pull one end of the cable taught and tighten the bolt. If you are not able to shift the chain, you can also turn the barrel adjuster away from the shifter’s body and do it again.
