Can I Put A Longer Rear Shock On My Mountain Bike?


If you are a fan of mountain biking over rough terrain, you’ll know that shocks play a vital role in comfort and performance. No one likes a spine-shaking ride! If your bike’s shocks need replacement or upgrading, you may have some questions about what to do and how to choose the right one for your bike. 

Can you put a longer rear shock on your mountain bike? Take some measurements to make sure a shock matches your bike height, weight, and overall movement. If you put too long of a rear shock, it can negatively affect your comfort. Do it right, though, and you’ll be able to absorb a lot of the shock well. 

There are a lot of measurements, physics, and geometry that go into finding the perfect rear shock that will fit your bike. It sounds daunting, but with the research I’ve done, we can do this together! We will go through everything step-by-step so that you will have a clear understanding of what kind of rear shock will work best for your bike! 

Do Your Research on Mountain Bike Shocks

Let’s start with the rear shocks themselves. So, a rear shock is made up of two parts: the shock and shaft. The shock is sometimes referred to as the eye-to-eye, which is the space between the two eyelets on either end of the shock. The stroke is the travel measurement, or how far the rear shock can travel and absorb the shock. 

Research your products. Don’t buy the first rear shock that you see! Quality is just as important as the measurements you took on which rear shock is best for your bike. You don’t want to waste all that time and research and buy a crummy rear shock that doesn’t do what it’s supposed to do. This one from Amazon has good reviews and is a great buy! 

Do the math. The leverage ratio is your best friend in this scenario. It will tell you what your rear wheel is capable of doing, and what it will do so you can plan for what rear shock will work accordingly. It is essentially: shock movement forward versus upward. Typically, most bikes are 2:1, or for every 1 millimeter of movement forward, there will be 2 upward. 

Check the suspension design of your bike. Mountain bikes are made differently depending on the brand and overall makeup of the bike. Your rear shock should help promote better suspension rather than hinder it with an ill-fitting rear shock attachment. Find the best rear shock that fits your bike rather than forcing one to work. 

Choosing a Shock for Your Mountain Bike 

The fit and size of the shock are crucial when selecting the right one for your bicycle.

You’ll overheat and overuse a poor-fitting rear shock faster than a well-fitting one. If your rear shock is too small for your bike, it will be working much harder to give you good movement and travel. This can overheat the shock, which will result in it needing to be oiled more often and have more chances of breaking while riding your mountain bike. 

The longer the rear shock, the more oil will be available to absorb the shock better. In this scenario, it does make sense to buy a longer rear shock. There will be more oil and space to absorb a lot of the movement of the bike while riding. It will also cope better with more erratic movements and bumps, equally for an overall enjoyable ride. 

Too long of a rear shock, and your movements will be limited. You only have a finite amount of space available by your rear tire, so if the rear shock is too long, then it will limit the amount of movement you can make as well as response to sudden jerks and turns. This is why measurement is key. Make sure you know how much space you have on your bike! 

Most mountain bikes have these measurements on the bike specifications for you. These can be found on newer bikes, especially. The measurements are listed as “eye-to-eye” and “stroke,” so you know what rear shock will best fit your bike. If you already have a rear shock and want to add an even larger one, measure the space first!  

The Measurement System for Bike Shocks

Companies making the shocks created a metric system with their products to help you. When shocks were first made, there were close to ninety different options to choose from. The lengths, sizes, and capabilities all varied greatly from one product to the next. It got to the point that it was too confusing for the average consumer to decide which to buy.  

There are now six major options when deciding on what shock will work best for your bike. The measurements take eye-to-eye and stroke measurements as their primary measurements to let you know how large or small each one is. Here are some examples of what the measurements look like: 

Eye-To-Eye [mm]Stroke [mm]
23065
23060
21055
19040

Less is more, for both manufacturer and consumer. Limiting the number of rear shocks that manufacturers make has really helped them home in on some really great pieces of equipment. This, in turn, helps the consumer enjoy a quality product that will help them get the most out of their biking experience. Everybody wins! 

Poorly fitted shocks can affect the ride as well as the condition of your bike. If you buy a shock that is too long for your bike, it will work well, but it can also damage it. The shock may be too long if your rear tire has moved at all after you installed it. Parts of the frame of your bike may also touch that aren’t supposed to, causing unnecessary damage. 

How Do I Know If I Have The Right Size Shock?

Check with your local bike shop. If you purchased a mountain bike from the store and are wanting to get a longer rear shock for it to help with the ride, take to a local bike shop associate. They will be knowledgeable and can probably do measurements with you in the store. They can recommend whether going with a longer shock is a good or bad idea. 

Read forums or post your own question. You are not the only mountain bike enthusiast who wants to get the best ride they can. Chances are, you are also not the only one with this exact question. Online forums can be great ways to read other people’s stories on what worked and what didn’t work for them. You can learn from their triumphs or mistakes. 

Check the fit of the shock on your bike. Once you’ve installed it, check and see if anything major has changed with the shape of your bike.

  • Have any of the tires moved out of alignment?
  • Are the frames scraping or wheel hitting the seat?
  • Do you sit more forward than you’d like to?

If you say yes to any of these, chances are the fit isn’t right for your bike. 

Summary 

We’ve discussed whether you can put a longer shock on your mountain bike. We’ve gone into the mathematics of how to figure it out as well as how you can objectively tell if the shock is a good fit for your bike.

All in all, make sure to do your research before putting a longer rear shock on your mountain bike.

Zach Reed

Hi, I'm Zach Reed and I'm a Colorado-based mountain biker! I spend my weekends cruising around on a Wasatch Peak Comp 29er and love every minute of it :) For more information, take a look at my dedicated about me page.

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