A rachet contains a round equipment or a linear rack with teeth, and a pivoting, spring-loaded finger known as a pawl that engages one's teeth. The teeth will be uniform but asymmetrical, with each tooth having a average slope on one edge and a much steeper slope on the various other edge.
When the teeth are relocating the unrestricted (i.e. forward) way, the pawl quickly slides up and over the gently sloped 
edges of the teeth, with a early spring forcing it (often with an audible 'click') into the depression between the teeth since it passes the hint of every tooth. When one's teeth move in the contrary (backward) direction, nevertheless, the pawl will capture Ratchets Wheel against the steeply sloped border of the 1st tooth it encounters, therefore locking it against the tooth and stopping any further motion for the reason that direction.
Backlash
Because the ratchet can only just stop backward action at discrete factors (i.electronic., at tooth boundaries), a ratchet does enable a restricted amount of backward action. This backward motion-which is bound to a maximum length equal to the spacing between your teeth-is called backlash. In cases where backlash must be minimized, a simple, toothless ratchet with a higher friction surface such as rubber may also be employed. The pawl bears against the surface at an angle so that any backward action may cause the pawl to jam against the surface and therefore prevent any more backward motion. Since the backward travel range is generally a function of the compressibility of the large friction surface, this device can lead to significantly reduced backlash.
This Ever-power 54t Ratchet kit works as a primary replacement and is super simple to install. Just remove the freehub human body the parts you observe here will maintain there, grease up the new parts and re-assemble the hub. Boom! You've merely significantly increased the engagement factors on your hub. To give you a better notion of how this improves your ride think about the engagements in examples of a circle, with the 18t you need to approach the cassette 20 degrees to attain another engagement and with the 54t that knocks it down to 6.66 degrees! That's less than a 3rd the length it needs to go to hit another tooth! You may be wondering if you can really start to see the difference. Merely pedal your bicycle around and keep the bike moving through the use of small pedal strokes and back-pedaling. You will see there's going to become lot's of slop between engagements. Think about if that "slop" was cut down to a third! I'm sure you can imagine that's a huge upgrade. So, in the event that you weren't already totally convinced on the 54t ratchet system I hope this is actually the turning point to getting one!