Kona introduced the air-sprung Coilair a couple of years ago, and for 2007 they extended the line to include a second model, the Supreme. With 160mm (6in) of travel front and rear, the bike is targeted at the aggressive all-mountain rider.
Crucially, Kona have also used their DOPE floating calliper braking arm technology to combat the brake jack that can upset suspension performance under hard braking. But is the extra £205 (or £220 for the 12mm kit) for the DOPE arm worth it for the performance return?
The Coilair Supreme shares the same frame as the other Coilair and Coilers. Beefed up with a box-profile front end, it uses 7005 aluminium tubing that tapers ovally and curves subtly into the bottom bracket. The steeply sloping top tube gets a pipe brace, and the seat tube is bulge reinforced at the point where it supports the rocker pivot of the rocker-activated single-pivot configuration. The back end also features replaceable quick-release dropouts, although a 12mm bolt-through kit can be added to truly stiffen things up for £56 more (not including a new hub/wheel). A full, uninterrupted seat tube allows the saddle to change from down low for drops to up on high for climbing.
The bike is decked out with top drawer parts, including a Fox 36 Float RC2 160mm (6in) fork, matched by a Fox DHX Air 5.0 shock. RaceFace supply an Atlas AM X-Type crankset with bashring and an Evolve AM oversize bar and stem combo. The brakes are Shimano hydraulic discs with 180mm (7in) rotors instead of the 203mm (8in) gravity norm. Burly riders might find the limits of the smaller brakes but, for the most part, they’re solid.
A 65.7-degree head angle working with a 70.7-degree seat angle on our 17in test frame, combined with a low 13.7in bottom bracket height, gives the Supreme poise and precision on the trail, making it at home on the tighter, techy stuff as well as North Shore and flowing trails. But at higher speeds over gnarlier terrain it isn’t quite so sure-footed. Instead it demands aggression to prevent it getting out of shape and is best suited to riders who come alive in the red mist. Rear end stiffness could be increased for gravity-orientated duties by buying the 12mm bolt through dropouts, because there’s noticeable flex at the back when seriously cranking, but for all-mountain convenience, the QR does the job.
Although more at home when things point downwards, the bike is capable of climbing – helped by the shock’s ProPedal which reduces pedal bob. And even though the bike (which weighs 16.45kg/36.26lbs) isn’t exactly sprightly, it will slowly grind upwards. Which brings us to the DOPE system – it works. It smoothes out brake jack in the rough under heavy braking, but only the fastest riders will truly appreciate its value – and by then they’ll be pushing the bike’s capability – because at £205 it’s not a cheap upgrade.