Do I Need a Coil Shock?
Yes I do. Then I'll look and ride like a pro (fat chance of that). Let's back the truck up a bit.
I've had the good fortune to try a few coil units on my bikes lately. I was amazed at the performance of the Push Industries Eleven Six but it's price and weight put a stumbling block in the middle of my brain. The Fox X2 coil again was superb but still at $1200 was a big ask to get permission from the wife to buy.. I mean that would pay for new curtains in the lounge. But now that Cane Creek have released this funky little Inline Coil jobby that will fit any bike and costs a mere $719 rrp and only adds 2-300 grams, all of a sudden Joe Public has a realistic chance at getting in with the In Crowd.
Coil is the original suspension platform for bicycles. Solid, reliable, heavy, non adjustable…gee you can see why there was a push to get a good air shock onto bikes. Look at all other off (and on) road vehicles and most of them have coils. The benefits are a lesser bump force to get it moving, a linear spring rate (it requires no extra force as it moves through its travel) and they rarely ever fail. In the real world this means great small bump capability, lots of travel all of the time and it doesn’t blow up. This is why they use them in bigger vehicles that get hammered where passenger/load weight is a variable feature but minimal compared to the weight of the vehicle.
But look at a bicycle and those attributes aren't enough. The benefits of air? Infinite tuneability to achieve perfect travel ratios dependant on rider weight and force of impacts, a progressive spring rate (requires added force the further it travels) and can be adjusted in 2 minutes. This means the right set-up for the trail/bike/rider with a more dynamic compression giving more “pop” and playfulness and you can change its behaviour out on the trail. Oh…and it’s lighter.
Air sounds so much better huh? So why are the cool kids riding coil? Because it’s cool that’s why? It’s new for trail bikes. Springs are lighter now and anti-bob pedal platforms now have way better technology.
Let’s look at the negatives.
Coil is heavier, you need to change springs for different riders and possibly trail types, usually comes only in 50lbs per inch increments so is difficult to get the perfect weight spring, bobs more from rider pedal input and relies on a 50 cent rubber bottom-out bumper to prevent end of stroke bottom-out.
Air requires a greater initial force to get started (seal friction = stiction), ramps up (progressive spring rate) so can feel too soft in mid stroke and too harsh at end stroke and more likely to blow a seal and dump air (though this is a rarity these days)
So you can see that coil shocks aren’t really better at all right? Wrong! Two factors: the initial suppleness and lack of stiction give incredible stutter bump (high speed roots and rocks) performance and due to the linear spring rate you are getting more travel out of your bike on each bump. What this means is that it feels AMAZING. If you can get the correct spring rate and your bike is designed to have a natural ramp-up (progressive spring rate) and the end of its stroke then you are in the money and it could be the best thing you did to your bike since adding a dropper post.
Back in the real world, your bike will feel like it has more travel, is smoother, eats high speed bumps better BUT may bottom out harshly on drops and g-outs, bob a bit more under pedalling and deaden the trail so your bike loses its playful nature. Yes, you have to decide what you prefer. I prefer both. Keep your air shock and swap them out for different trails. That’s what I do.
Rod “wound like a spring” Bardsley.