The best coil shocks are enjoying something of a resurgence at the moment as riders look for extra grip and damping performance on more challenging terrain, be that steeper or rougher. While it’s mostly enduro bikes and e-bikes that are seeing aftermarket upgrades from performance-hungry riders, some progressive trail bikes are starting to get in on the act too, now that brands are beginning to design models with kinematics that work with the characteristics of a coil spring.

The Marzocchi Bomber CR shock is ostensibly the Fox Vanilla RC from a decade ago, rebranded… but this is no bad thing when you’re looking for stiction free performance and simplicity

So now the barrier is less about compatibility and more about cost, both in terms of weight and price. A new Ohlins TTX shock will set you back £795 for example, and the EXT Storia is over £1,000. So Marzocchi’s Bomber CR is relatively affordable at £345 (add a further £46.95 for the spring), and this means it will be of interest to anyone looking to upgrade or replace their original shock. Marzocchi certainly isn’t shy in offering it in pretty much every shock dimension – and mounting standard – under the sun.

The Bomber RC is essentially the classic Fox Vanilla RC rebranded. Although this kinda means it’s a shock from a decade ago, that’s not necessarily a bad thing when you’re dealing with coil shocks.

The whole benefit of a coil shock is to do away with all the inherently air-based issues that air shocks have spent the past ten years trying to iron out. What are those issues? Stiction, and non-linear spring curves. Despite drastic improvements in air shocks’ suppleness and the development of tuneable end strokes, there can be undesirable qualities to air shocks’ mid-strokes. They can lack support.

Now a whole load of this depends on the frame design. But as air shocks have had their undesirable qualities tuned out, so frame linkages have become more adaptable to either spring material, to the point where the linear curve of coil works better with more bikes these days. This, and the general move away from weight weenie concerns, has contributed to the comeback of coil.

Low speed compression dial, hard to turn but oh so effective at smoothing out the terrain

The absence of any progressive end stroke to this Bomber CR could make still make it unsuitable for certain very linear frames even if there is a Nitrile rubber bottom-out bumper for dealing with full travel moments.

There are companies who make progressively wound coils, which is one potential solution if you own a linear bike and still really want to go coil. You can also opt to run a firmer spring so long as you’re okay with less sag and a higher ride height/less dynamic sag.

Although ostensibly simpler, I actually found setting up the Bomber CR rather drawn out. You really need a good bike shop to sort you out with the correct spring to start with as online spring calculators are a minefield! With this sorted, my next issue was all about not knowing how to set sag. The best option is to use the bottom out bumper like an O-ring – push it up the shaft to the damper, sit on the bike, then measure the distance between the damper and the bumper to get your sag.

Getting the correct spring strength is what it’s all about when setting up the Bomber, then sort your rebound via the red dial

With the shock installed on my Cotic FlareMax and the sag set, the difference was simply amazing. Okay, so there’s definitely less pop and the bike doesn’t feel quite as responsive to rider inputs, but when the traction is this good… who cares? Not really; pop and responsiveness are both important. What I did find surprising however was that post-sag (mid-stroke) support was significantly better on the Bomber CR compared to air shocks. This goes a long way to offset the lack of insta-pop when exiting corners or on lips of jumps.

Coil is amazing when the conditions and/or the terrain suits. I can see myself opting to run an air shock in summer/autumn and switching to coil in winter/spring just as I do with specific tyre treads. Or maybe I won’t, since the sheer comfort from a coil shock is a real unspoken win too. I’m less fatigued after rides on coil, despite them being heavier and more supple. I think this is especially true for flat pedal users. And that midstroke feel is similarly addictive.

What else? The price is great. The relative lack of servicing is nice. Niggles? The low speed compression dial is hard to turn. The rebound dial ‘lost’ its detents after a few filthy rides.

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