Have you ever wondered about the difference between an air vs coil shock?
These suspension designs are standard among full-suspension mountain bikes and work on the same principle—they absorb shock from impact. However, they offer riders different benefits, making them suitable for different riding needs.
If you wish to know their differences and which is better for your riding needs, keep reading. We will explore how they each work, when to use them, and the pros and cons between air vs coil shocks. Let’s dive in.
Contents
Air Shocks
Air shocks are also called air springs. In the late 1990s, during the experimental phase of mountain biking, very few air shocks could offer good performance on descents. Seals would break, overheat, leak oil, and throw up other issues.
However, since the mid-2000s, these models have improved drastically and have become more common on full-suspension bike frames.
How Do Air Shocks Work?
Air shocks harness pressurized air for compression resistance to absorb shocks while riding. The spring in an air shock comes from compressed air in a can or airtight chamber inside the shock’s body. When the air gets compressed, it resists additional compression.
Air shocks have a progressive spring rate, which makes the suspension more challenging to compress while traveling throughout the suspension range. This causes the stiffness to increase tremendously. The design of an air shock makes it most suitable for a frame with a progressive or linear spring rate.
To adjust the spring rate of an air shock, you need to change the air pressure inside the shock. To do this, you need a shock pump, which is a special high-pressure pump. It has different controls for adjusting the sag and preload of the shock.
Many models also enable you to use spacers to change the volume of air inside the air chamber so you can adjust the progression.
When To Use Air Shocks
Air shocks are best for mountain biking. Nowadays, these suspension designs are pretty common, and almost every full-suspension bike has them fitted in. They are beneficial for enduro and trail mountain bikes.
This is because they have a progressive spring rate that gives the bike extra support on large bumps, rollers, jumps, and drops. These shocks are also lightweight and allow bikers to climb hills smoothly. A lighter bike also lets you bunny hop more easily.
However, they are not so popular among downhill and freeride mountain bikers. This is because they have many seals that create friction and heat, especially on descents. This causes extra stiffness in the shocks and leads to poor riding safety and performance.
Pros
- Air shocks are highly adjustable, as you can precisely tune different aspects of the behavior of the suspension.
- You can also change the spring rate or stiffness of an air shock to suit your comfort level and the riding terrain.
- Air shocks do not need replacement now and then to suit the rider’s weight.
- Air shocks are lighter than coil shocks, which translates to a lighter bike. They allow you to ride faster and navigate the riding terrain more smoothly and easily.
- An air shock offers better bottom-out resistance than a coil shock.
- Air shocks usually cost less than coil shocks.
- Air shocks are compatible with almost all kinds of suspension bike frames.
- An air shock operates more quietly than a coil shock.
Cons
- Air shocks need a high level of maintenance as they have many internal seals that attract dust, sand, dirt, and grime.
- Air shocks heat up much more than coil shocks on long rides, as the seals create friction and cause wear and tear.
- An air shock is not as sensitive to bumps on the ground as a coil shock. It has more seals, so it requires more breakaway force. As a result, it lacks slightly in the shock absorption department. This provides a rougher, slower riding experience on bumpy ground.
- Air shocks offer lower traction, grip, and stability than coil shocks owing to their decreased sensitivity to bumps. This prevents you from braking or taking corners hard and quickly, as your bike wheels may skid or slide out from under you.
- Air shocks are more fragile than coil shocks. So, they do not last as long as the latter.
Coil Shocks
Coil shocks are also called coil-over. Every dual-suspension bike had them in the 1990s. Due to the advancements in air shocks, they have taken a backseat in recent decades.
But coil shocks still offer many unique benefits that air shocks lack. So, they have been making a comeback on many bike models, mainly downhill and trail bikes.
How Do Coil Shocks Work?
Coil shocks use a wound spring made of titanium or steel to offer resistance and absorb shocks while riding. They have a linear spring rate, which means that the amount of pressure it takes to compress the spring constantly increases throughout the suspension range.
Coil shocks do not offer good bottom-out resistance due to the linear spring rate. This makes them best for bike frames that have a progressive spring rate. Coil shocks also need fewer internal seals, as they do not have to be airtight. Unlike air springs, they do not need to hold air under high pressure.
Seals tend to increase friction in the movement of the shock. So, a steel coil will generally need less breakaway force to start moving. It is also more sensitive to small bumps and other imperfections on the riding surface. This increased sensitivity improves grip and traction and keeps the back wheel tracking the terrain. This helps improve the comfort and control of the ride and enhances riding performance.
If you wish to adjust the spring rate of a coil shock, you can replace the metal coil with a softer or stiffer spring. The coil shock also has a knob that allows you to adjust the preload and sag. This helps compress or decompress the coil.
When to Use Coil Shocks?
Coil shocks are common on downhill mountain bikes. This is because a steel coil shock can manage heat on long descents better than an air shock and is also easier to maintain. This enables better riding performance and safety and allows bikers to ride for long hours.
Coil shocks are reappearing on enduro and trail mountain bikes owing to their many benefits. Learn more about their advantages below.
Pros
- Coil shocks do not have many internal seals, so they do not need as much maintenance as air shocks do.
- A coil shock does not heat up as much as an air shock does with heavy use.
- Coil shocks are highly sensitive to small bumps and other imperfections on the road than air shocks. This is because they have fewer seals and require less breakaway force, so they can absorb shocks better. This provides a faster, smoother, and more comfortable ride on bumpy terrain.
- A coil shock provides better grip, traction, and stability than an air shock due to its superior sensitivity to small bumps. This allows you to take corners and brake faster and harder without worrying about your bike wheel sliding out or skidding.
- Coil shocks are slightly more long-lasting and sturdier than air shocks and can deal with neglect better.
Cons
- You do not get too many adjustment options with coil shocks. They are also harder to adjust.
- Changing rider weight often requires the replacement of a steel coil shock with a new one with a different spring rate.
- Coil shocks are usually heavier than air shocks as they have a heavy metal coil. A coil shock with a high spring rate will have a thicker gauge metal for additional stiffness. This leads to a heavier bike, making it harder to climb slopes smoothly.
- Coil shocks provide poorer bottom-out resistance than air shocks. This can cause severe damage to the spring and other bike parts at high speeds.
- Generally, coil shocks are a little more expensive than air shocks.
- Coil shocks are incompatible with suspension bike frames with a linear leverage ratio.
- A coil shock can be noisier than an air shock if the coil is loose and knocks against its bases.
Air vs coil Shocks – Which One Is Better for Me?
A coil shock is better for you if you ride regularly in bike parks or downhill trails. It will help you avoid overheating, friction, and other riding issues and tackle small bumps better. It also lets you keep maintenance costs to a minimum compared to air shocks.
Meanwhile, an air shock is better for those who mostly ride on flatter terrain or uphill. It helps riders enjoy a more lightweight bike and ride faster and more smoothly on slopes. It also offers more progression to prevent bottoming out on big hits.
Moreover, it is great for those who need to regularly adjust the spring rate or other aspects of the shock to suit the riding terrain, rider’s weight, and so on.
Conclusion
Choose a type of shock that suits your riding needs and comfort level the most. This will help you get more bang for your buck and enjoy a superior riding performance.
If you found our article on air vs coil shocks useful, do check out more such biking articles and guides on our website. Happy reading!
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Last Updated on November 23, 2022 by Matthew Carpenter
