I never rode a coil shock but am seeing it more and more. Can anyone describe how it’s different feeling? I can imagine that an air shock could heat up and as a result become firmer- but I have never noticed that.
Honestly, most would not be able to tell much difference. A fork or shock with a spring will always be more reliable and better to be able to handle big hits but for most an air shock is more than acceptable.
Raced and tested both types in motocross and even today would go for coil suspension but am more than happy with air suspension on a MTB.
Sorry, I'm definitely no expert on this but surely an air shock is better able to tolerate big hits? I'm thinking back to fournales shocks on motorbikes - impossible to completely bottom out because the effective spring rate ramps up as you compress them? ( I remember snapping suspension bolts when doung silly things with a fournales shock......)
Springs always gave a better ride once you had customised spring rates and preload to suit the rider - so for high end users they can be set up better. Again, motorbike knowledge - not mtb so I could be showing my ignorance here?
Spring = linear ratio (ignoring progressive springs)
Air = progressive ratio
Now we got the physics out of the way here are the pros and cons in breif.
Coil
Pro - supreme small bump performance and grip, longer service intervals, no stiction.
Con - linear by design, if the frames kinematics (suspension design) is not progressive enough (rising rate) then bottom outs can occur on harsh landings and drops with a frame design that doesn’t have enough progression Or too low spring rate.
Air is infinitely adjustable in spring rate, coil shock takes spring rates in 25/50lb increments. It can be costly to get the goldilocks sag point. 25 or 30 is just a guide and some bikes work best well outside this ballpark. It could take several spring rates to find the right one meaning added expense.
Air
Pro - progressive by design for regressive or linear frame designs. Infinitely adjustable for spring rate and air volume within reason.
Con - lower performing small bump compliance when compared to coil (this gap has been bridged significantly recently)
Service intervals more frequent.
IMO, the ultimate is large volume air shocks with high and low speed compression and rebound adjustment, such as fox x2, cane creek double barrel air. Small bump compliance with added ramp up of air with all the adjustment in the world to suit any rider without custom tuning.
This is coming from a diehard coil fan too. I’ve seen the light.