Today not many bikes come with dual shocks on the rear, and those who do are the budget commuter ones which concentrate more on giving more distance to the fuel burnt and also being able to carry as much as weight it is asked to carry like a fully laden donkey. So when companies actually decided on designing bikes for the commuters, they realized that there is no practical decision in giving monoshocks to the bikes since they will be put under a lot of stress and hence it would result in more damage than good of the bikes.Hence they decided to go with the same dual shocks at the rear for the commuters and some other mid-sports bikes which couple as commuters. So what resulted eventually were various types of dual shocks which are being fitted on various bikes depending on their cost, the expected kind of use and also the complimenting looks. So here we are going to check out the various kinds of dual shock absorbers available for the bikes as follows:
1. Hydraulic Spring Loaded Shocks:
These are the conventional types of shocks available. They are the first kind of shocks that were used which had a hydraulic piston inside suspended with hydraulic fluid inside it and the outer end had a spring loaded on it to provide additional support. These shocks have great efficiency and the load bearing and bump absorbing capability of the shocks can be easily tweaked by changing and adjusting the hydraulic fluid inside it by using a different viscosity fluid.These are the highly used shocks and are functional even today on low cost commuter bikes. They are sturdy, keep the bike stable on the worst of roads and are capable of handling the heaviest of loads. They even last a long time and are pretty much zero maintenance in most cases as well which is really awesome and they are even cheap to produce and hence are ideal in low cost bikes.
2. Nitrox or Gas-filled Shocks:
These are the dual version of the single mono-shocks that are on most of the sports bikes today. They work on pretty much the same principle of regular hydraulic shock absorbers with a small change that they use nitrox gas or other gas. The reason for this is because the gas used has a very loose molecular structure and it has the elasticity capability as well. For this reason when the bike hits bumps the gas inside gets compressed leading to absorption of shocks and later the elastic nature brings the shocks back to the original shape and form.Since they are very useful in performance areas owing to its lighter weight and higher stability overall, they are used in some of the medium performance machines that are equipped with dual shocks like the Hero Karizma R and ZMR series of bikes.
3. SNS Shocks:
These are actually quite interesting and are something that was invented and patented by Bajaj Auto here in India. The idea behind them is really simple. Instead of using hydraulic fluids and gases it uses a Spring in Spring system where two spring are suspended to each other in there. What this does is, it makes two springs suspending the shocks, the one on the inside as the main load bearing one and the outer spring acting as a support to it to limit the spring action and rebound. This way by using the two springs the shocks work well and are quite capable as well.The advantage of this is it keeps the cost low and hence they are used in most of the Bajaj commuter range of bikes. Also this makes maintenance a lot easier since there is no hydraulic fluid or gas to take care of in any case which makes it the most ideal one on paper but it still has its own chinks in the armor.
So these are our 3 different kinds of dual shock absorbers that are being used on many of the bikes plying on the road. Even though they are the thing of the past in terms of performance bikes, still one cannot really let go off the advantages this has to mono-suspension and hence the reason why they are being used still.
By: Pratik Patole