Mortal Coils! Benji and the crew look at coil shocks and explain why they’re for trail riders and not just for downhillers.
With this Kit Essentials feature we’d like to de-mystify and de-macho the whole thing about coil shocks. They aren’t just for Red Bull Rampagers, Hardliners, or racers seeking better heat management. Every single mountain biker can benefit from going coil, if they want to. We’re going to try not to be overly preachy about coil suspension (although coils really are great, sorry). If you’re happy with your air shock, that’s fine, they are pretty darned good.
But good as they may be – and convenient for the retailer that needs one component to fit all – air shocks just aren’t as good as coils. Honest. Despite what manufacturers can do with modern air shocks (better seals, larger and larger negative air chambers for suppler sag, etc.), coils are just more consistent. This isn’t bike journo waffle, it’s maths. Air shocks have seals to keep the air in, which give friction – or ‘stiction’. Coils are supple – there are no stictiony seals. You can make some of the coil shocks reviewed here compress just by pushing down on the saddle with a single finger. Does that make them a complete unpedal-able mess? No, not really. The damping quells the trampoline. Coil shocks don’t bob significantly more or less than a modern, large-negative-chambered air shock. The only air shocks that don’t bob (as much) are those that are so stictiony they aren’t doing much actual suspension duties.
At the end of the travel, all the air in an air shock is compressed, making it harder to use that last bit of travel – they have a progressive spring rate. Combined with the stiction at the start and the negative air spring in the middle, this gives an S-shaped graph (see our interactive über-graph above) as you move through the travel of an air shock. In comparison, coil spring rates are linear – the graph is a straight line. It’s consistent. It’s maths, see?
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Consistency is good – you’re getting the same amount of support wherever you are in the travel. Once you’ve ridden a coil or – more accurately – once you’ve ridden a coil and then go back to an air shock, you’ll notice how air shocks feel like they have two parts to their travel: the sag point and the end stroke. A lot of air shocks don’t really have much of a detectable, push-against-able, workable middle zone. This means better bike handling on a coil shock, because you can feel what’s going on underneath you, and the support, feedback and feel are wholly consistent throughout the travel.
That suppleness that helps give you consistency, also gives you traction. A coil shock hoovers up traction like there’s no tomorrow. This is good everywhere. Coil shocks will successfully get up more climbs than an air shock. They will hold their line better across off-camber roots. They will do their damnedest to not slide-out on filth. The other nice thing about a coil’s reduced friction is, quite simply, that it’s more comfortable. Regardless of any pedal bob argument you may hear on The Internet, the fact that coil-sprung rides end with the rider feeling far less jarred, clenched and fatigued is a real win here.
Oh, and as for weight. Yep, coil shocks are heavier than air shocks. Now is the not time or place to discuss the whys and wherefores of weight again. We’d just say that we feel less tired and beaten up after a coil sprung ride. If you are really concerned about weight, then there are brands that make lighter weight springs to save some grams. You could even have a titanium one.
How to go coil
We would strongly recommend going to the bike shop. This will overcome the single main hurdle in ‘going coil’, namely, getting the correct weight spring. Go to a decent bike shop, they should be able to get two or three different springs for you to set your sag with. Keep the correct one, give the others back. For the purposes of this test we experimented with a few different online spring calculators and they were at best 50/50 in whether they got it right or not. The bike shop will also obviously help with installing the correct mounts/bushings/etc for your bike.
The other thing we would advise is to stop worrying about perfect setup and just ride the thing. Dial all compression dials to open, rebound to mid and go for a ride or two before tweaking as and when you discover a characteristic you want to reduce/increase. But please just give it time or you’ll just end up chasing your tail. Get used to the feel of coil first. Fine tune later. That’s the other great thing about coils compared to finicky air shocks; they don’t need setting-up ‘just so’ for them to work really, really well.
Finally, a quick word about frame design. Occasionally some manufactures will say that a frame is not compatible with coil shocks. You should probably listen to them…warranty and all that…
Unless your frame is explicitly excluded from coil compatibility, there are a few design considerations to take into account. Firstly, coil shocks can take up more frame real estate than an air shock. The main culprit is the piggyback reservoir clashing with a frame member or a water bottle. Do some measuring first (you can find the dimension of the shocks on the manufacturers’ websites). If in doubt, go for coil shock designs that have the piggyback brought in/away from the eyelet end of the shock: Fox, Marzocchi and DVO offered the most clearance.
Another thing regarding frame design is the leverage rate. A lot of nonsense is talked about bikes requiring super progressive leverage rates to properly work with the linearity of coil shocks. Single pivot Orange bikes apparently ‘don’t work’ with coils according to various keyboard warriors. The thing is, in our experience, they do. They work really, really, well. Where you may have an issue is on multi-link rear suspension designs. Some can have linear-to-the-point-of-falling leverage rates. In which case, all is not lost. Companies like Cane Creek offer progressive rate springs (around £90).
While we’re talking linkages, a final consideration is that skinnier coil shock shafts can’t deal with the side-loads that some yoke or linkage systems may place on them, causing them to eat themselves. In these instances, you should consider a shock with a thicker shaft.
Coil shock reviews:
The Verdict
We’ll be totally honest here. Like we always are, but we thought we’d preface this verdict anyway… We were quite worried while carrying out this test. Mainly we worried that we couldn’t really separate these shocks from each other in terms of their performance. They all felt the same. They all felt great. This was something of a problem. Grouptests, which is essentially what Singletrack Kit Essentials is, are supposed to find differences and objectively order test items in terms of how they function. You can’t just say “they all felt the same”. Well, Singletrack could do because we tell it like we find it, but you know what we mean.
Fundamentally, this test was very probably the hardest test we’ve ever done. It certainly took far longer than we expected it to. But the extra time period of testing was well worth doing. All of these coil shocks are great. But they are not all the same.
Now then, they are all undeniably similar to each other – which is interesting in itself – but there are some that exhibit certain traits more than the others do.
Starting reverse alphabetically, just because, the X-Fusion H3P RCP is a well-priced and well-made shock that was tricky to set-up (sag vs rebound) but for those that like plenty of sag, or those who only want to spend £300, it’s a sound choice.
The RockShox Super Deluxe Ultimate RCT Coil was something of a dark horse. For whatever reason, RockShox coils may not have the cachet of some (OEM overfamiliarity?) but the Super Deluxe Ultimate RCT offers exceptional performance without a ridiculous price tag. Definitely the best mid-price option.
The MRP Hazzard really won us over. First of all by how well it appears to be made and certainly be how nice the dials, lever and collar are to use. But secondly by how insanely supple it was. Totally beguiling and addictive. Compared to the similarly priced Cane Creek Kitsuma Coil, it’s hard to pick a winner. It mainly depends on what you like. The Kitsuma has more support in the middle – and thus feels more responsive and ‘poppy’ – but the Hazzard just feels so good and… coily.
The Marzocchi Bomber CR was another great performer on the trail. Is it worth the extra £50 over the X-Fusion? Not in terms of theoretical on-paper adjustabilty (there’s no climb switch) but we did find it had a larger sweet spot in terms of spring weight and rebound set-up. So yes, it is worth the extra money.
The Fox DHX on the face of it appears to be a tad overpriced. Sure, it has a climb switch but what else? It’s pretty sparse on the external adjustment front. What gives? What gives is the damping performance, and the niceness of the physical external adjustments that it has. If you need to know such things, we think it just edges the RockShox in terms of sheer performance. It lets its guts do the talking.
The DVO Jade X may not offer quite the top level of performance as some of the shocks in this test but it’s more than acceptable on the trail. It’s… yep, you guessed it… great. What the DVO has going for it is a couple of practical factors. Firstly, it will fit a lot of frames that other shocks here will foul. And secondly, it really is home serviceable. There’s a reason why DVO has its vocal fans out there.
Which leaves us with the Cane Creek Kitsuma Coil. And, goshdarn it, if it isn’t The Best Coil Shock here. That’s annoying. It’s always nice to say that the most expensive product isn’t the best in test. And we very nearly overthought our way into declaring the RockShox Super Deluxe Ultimate RCT as The Best In Test (as it is, RockShox can definitely have the Best Value In Test accolade here). In the end though, if we focus on the job rather than the price tag, it’s the Cane Creek that takes the win. It had all the best bits of all the other shocks in one package. The one and only thing you can complain about is that there might be too many adjustments for the complete layperson to comprehend. But even then, all that person has to do is read Cane Creek’s recommended settings, dial them in and never touch it again. Super supple, super supportive, supremely well made. And as regards ‘value’, we think it outperforms many of the four-figure über shocks out there.
Just to reiterate our main, over-arching finding with this test: all of these coil shocks are great. We can’t think of any air shock that we’d run in place of any of them. Finally, the other key takeaway we had here was that we couldn’t help wishing there were more coil sprung forks on the market. Coil front and rear? Yes please!
