Air Vs. Coil
Mountain bike technology has come a long way in the past 20 years. Having moved on from very basic elastomers and underdamped po-go like sprung suspension of the naughties, we are now in an era where we are have an almost infinite range of adjustments on a shock, and the choice between an air or coil sprung damper. With different options available and every bike having slightly different kinematics and ride characteristics it can indeed be difficult to work out which is best for you.
There is a reason the vast majority of enduro mountain bikes come with an air sprung shock; air shocks are incredibly easy to setup - All that's required is a shock pump and you can set the correct amount of sag easily. This is much more appealing to the mass market, as bike shops aren't required to keep a large stock of different size/rate/fitment springs.
It is also very simple to adjust the amount of ending stroke ramp up by adding or removing air volume spacers which are quite easy to get hold of. Air shocks are also slightly lighter than most coil shocks as they don't require a spring, however with an up-surge in demand for coil sprung dampers thanks to Enduro World Series atheletes wanting more from their suspension, manufacturers have worked hard to refine dampers and save weight where possible - Couple this with a lightweight titanium spring and you have a setup that is really not much heavier than an air sprung shock at all!
Air sprung shocks however do work great on some bikes, specifically those with a falling rate suspension design, where ending stroke ramp up is crucial to avoid a harsh bottom out. This can be understood simply by physics; as the air is compressed the particles are pushed closer together and air has less space to go, causing the shock to ramp up and become stiffer. This can be acheived with a coil shock, but often not without using alot of compression and setting up a custom shim stack inside the shock itself.
There is also a reason the vast majortity of downhill mountain bikes come with a coil sprung shock; coil shocks provide alot more grip. While modern air shocks do have very good small bump sensitivity, the super supple, ground-hugging feel of a coil shock is simply unrivalled. Downhill riders require this more than anything, as their wheels need to be firmly planted to the ground as they constantly battle to find grip whislt tearing down the mountain at speed! Coil sprung shocks are also much more consistant as they are not relying on air for support, but rather a spring. On long, rough, descents, air shocks are renowned for getting very hot and this can cause the damping to stop working properly. In fact it is not uncommon for seals on air shocks to fail and/or need replacing in some conditions. Compare this to a coil spring shock where it is not uncommon for a well made damper to go a whole season without a service and still perform faultlessly - They are reliable!
The vast majority of coil sprung shocks on the market are now available with some sort of climb switch; a lever that allows you to lock out or increase the compression on the shock at the flick of a finger - This is a really useful feature for enduro mountain bike riders as it improves pedalling efficiency whilst climbing - Previously a feature that was only available on air sprung shocks.
With our wide range of lightweight titanium springs, available in 25lbs/in increments up to 650lbs/in, it has never been easier for a rider to find the perfect spring rate/size/fitment for their coil shock, and this is another reason why we are seeing more and more riders and bike companies switch to coil sprung dampers.
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