- Kona CoilAir Supreme
- Magic Link variable-travel suspension
- Top-drawer spec
All dimensions based on 18in frame
|Effective top tube length (TT)||600mm (23.6in)|
|Chainstay (CS)||445mm (17.5in)|
|BB height (BB)||365mm (14.4in)|
Kona’s long-travel CoilAir has been in the range for a number of years with only minor tweaks, but for 2008 it was completely redesigned to incorporate the Magic Link suspension system. Magic Link is the work of Brake Therapy’s Brian Berthold, whose floating rear brake system has appeared on a number of long-travel Konas under the DOPE name. Magic Link takes the idea of making brake forces work for the suspension to another level, though.
The bike pictured is the 2008 model, but not a great deal has changed for 2009. The most obvious difference is the switch to Fox 36RC2 fork rather than the Marzocchi prongs shown here. It’s also red and white rather than plain white. The rest of the spec is unchanged, although the price has gone up by (gulp) over £1,000.
None of this will affect the performance of the Magic Link platform itself, though. Let’s dive in…
The 2009 frame has a couple of less-obvious changes from the 2008 one. The only really significant one is a switch to a 1.5/1.125in head tube to accommodate the new crop of tapered-steerer forks. Apart from that, it’s Kona business as usual up front, with big, square-section 7005 aluminum tubing.
In fact, the whole top half of the frame looks entirely familiar, with a long rocker arm having a Fox RP23 shock at one end and a pair of seatstays at the other. The hind quarters hold no surprises either, with Kona’s usual bolt-on dropouts and chunky chainstays.
Head towards the bottom bracket, though, and it all starts coming from Mars. Where you’d expect the chainstays to attach to a pivot somewhere behind the BB shell, instead they sail on underneath before arcing up to a pivot ahead and in front of it. That pivot is mounted to the Magic Link itself, which pivots off the frame at the bottom and has the shock attached to the top.
Confused yet? Stick with it. There’s also an additional spring between the Magic Link and the seat tube, which acts to hold the Magic Link forward. If everything was fixed in this position, you’d get 6in of travel. But as the suspension compresses, the Magic Link rotates backwards, altering the geometry and rate curves and ultimately delivering 7.4in of travel. Which is quite a lot.
So far so good. But it’s having the chainstays attached to the link too that’s the really magic part. Pedalling pushes the stays forwards, holding the suspension in its shorter-travel, stiffer mode. Braking pulls them back, rotating the link straight into the long-travel mode. As well as changing the behaviour of the suspension, as the link rotates back the BB drops, the angles slacken and the effective chainstay length increases (not necessarily in that order).
It’s quite a lot to get your head around, and there’s a fair bit of setting up to do (of which more later) but it’s not quite as complicated as it first appears.
You’d hope for a pretty spectacular array of parts for the asking price of the CoilAir Supreme, and to be fair it’s all top-drawer stuff. You’re getting Mavic CrossMax ST wheels shod with 2.35in Maxxis High Roller tyres, Shimano XT brakes and transmission (with a rear mech upgrade to a perhaps unnecessarily pimpy XTR Shadow carbon-caged unit), Race Face Atlas AM twin-and-bash chainset, bars and stem and so on.
It’s all good, but even so it’s hard not to feel just a little short-changed. This is a £4,400 bike. Sure, prices have ramped up for 2009, but it still seems like a huge pile of money in pure spec terms. By way of comparison, Trek’s Remedy 9 is similarly specced and costs a grand and a half less.
All full suspension bikes come with something of a setup overhead, but the Magic Link comes with a whole extra layer of fiddling. As well as the usual air pressure/rebound settings, the Link itself needs setting according to your weight and riding style. There’s a choice of mounting holes, adjustable preload on the secondary spring, interchangeable elastomers… The supplied instructions are pretty clear, although the suggestion to use digital calipers to get the preload set to the nearest mm is likely to be a little offputting for less experienced riders. You’re likely to have a few goes at getting it right, too – we were fiddling for the first couple of rides until it felt like it was doing the right thing at the right time.
One of the more unique characteristics of the Magic Link CoilAir is its behaviour under braking. There’s a lot of witter out there about “brake jack” on full suspension frames, but for the most part it’s just a consquence of having lots of travel at both ends. Brake hard on a long-forked hardtail and you get a forward weight shift and some fork compression. If the back end is on pivots too, it tends to unfold itself. Various floating brake setups are around that aim to counteract this mechanically, but the Magic Link goes a step further.
As you brake, the Magic Link rotates backwards into the long-travel position and the suddenly-softer back end sucks itself on to the trail like a remora on a shark. The faster you’re going the more pronounced this effect seems to be, and it’s quite fantastic. We rode some steep, fast, bermed trails on the CoilAir, and a whiff of brakes on the way in to the corners had the bike hunkering into the berms like a pre-pounce cat. It takes a little getting used to – the whole balance of the bike shifts in what is, at first, an entirely unexpected direction and we nearly lost the front wheel the first couple of times. When you get into it, you find you can stay over the front end a lot more than you may be used to.
When it’s time to pedal, you get the same effect in reverse – the bike steepens and stiffens and picks up speed with a degree of alacrity that you really don’t expect. There’s never any sensation of abrupt switching between travel modes – the Magic Link is constantly moving, and it’s only really the extremes of hard pedalling or braking that force it to one end or the other.
On long climbs the CoilAir’s 34lb weight makes its presence felt – even with the Magic working with you, this is still a big, heavy, long-travel bike. The cunning suspension makes it tolerable to haul a very capable bike up hills, but you’ve got to want such a big bike in the first place – we can’t help thinking that most UK riders would benefit from the same system in a lighter, shorter-travel package. For our money, a bike that topped out at 6in but felt like 4-4.5 most of the time (and weighed under 30lb) would be a considerably more useful tool.
There’s no denying the CoilAir’s fun factor on the descents, though. The handling is great, that inch-plus of extra travel arrives just when you want it (once you’ve got the setup sorted) and all the parts work great. The only exception was the Marzocchi 55 fork, which felt notchy out of the box and never really got any better than “a bit blunt”. That’s kind of moot, though, given the 2009 switch to a Fox fork.
Ups and downs
Positives: Self-adjusting suspension that works, air of unstoppability, top-drawer spec
Negatives: Expensive, pernickety setup, still a big old bike to haul around
Yes, bikes and kit are all more expensive in 2009, but even so, the CoilAir Supreme is quite startlingly pricey, although cheaper (and heavier) models are available. The Magic Link certainly works as claimed (although setting it up and getting the best out of it presents a bit of a learning curve). If you’re in the market for an extra-long-travel bike that you can actually get to places under your own steam, the CoilAir is well worth a look. We’d love to see the system on a shorter-travel, handier bike, though.