Commencal has a rich history when it comes to making race winning downhill bikes. The pedigree goes all the way back to the nineties when the brand’s founder, Max Commencal, helped design one of the most successful downhill bikes of all time when he worked with legendary French brand Sunn. Then, as now, he isn’t afraid to try different things in the search for speed, and this is the fourth iteration of the Commencal Supreme — and it’s quite a radical departure from the previous bikes, especially when it comes to suspension design.
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Called the HPP system, it’s essentially an ordinary linkage driven single pivot but with a couple of differences that turn it into something rather exotic. The biggest difference is that instead of being at roughly the same level as the top of the chainring, the pivot for the swingarm is considerably higher. This means you get a much more rearward axle path, which Commencal reckons gives improved bump performance.
It also means that the wheelbase grows significantly as the suspension compresses, improving stability when you’re deep into the travel. Such a high pivot point would usually cause huge issues with chain growth and pedal kickback as the suspension compresses, so to get around this the extra long chain takes a more circuitous route, threading vertically up from the cranks and then over the main pivot and back to the cassette via an idler cog. That means that chain tension from pedalling — anti-squat — no longer has such a great effect on suspension performance.
This isn’t a new idea by any means, but the Supreme is one of very few modern bikes to use this system and Commencal is pretty much the only mainstream manufacturer to do so. The suspension also boasts 220mm of rear wheel travel compared to 200mm up front, when most bikes on the race circuit have 200mm at either end.
As well as there being more of it, it’s also more progressive relative to the old Supreme, with a shock leverage curve that’s been tweaked to be more sensitive at the start of the stroke and with greater support in the middle — thanks to the rat’s nest of linkages and levers that drive the low slung shock.
Compared to the suspension, the rest of the bike is pretty traditional. The frame is all-aluminium with internal cable routing and there are some neat integrated fork bumpers set behind the head tube. There are other trick touches too, such as the built in rear mudguard and downtube protector, while the space left open in the downtube for the shock to sit in is stuffed with plastic wool to prevent mud from accumulating there.
Elsewhere you can adjust the reach of the bike by using offset headset inserts, and at a rather short 407mm for a size large you’ll probably want to stretch it out as far as it’ll go — unless you’re a fan of tiny front ends. It’s worth noting that at 62.5 degrees, the head angle is pretty much spot on for inspiring confidence on fast and steep trails, while a relatively short stack height gives you plenty of options when it comes to getting your bars in the right place.
The static chainstay length is a tight 425mm, but don’t let the figures fool you because as soon as the suspension compresses they grow significantly, ending up at over 465mm long at full travel. That’s really quite noticeable when you’re trying to pull manuals at low speed, especially with the ‘folding in the middle’ feel as the suspension compresses. However, once the pace is higher it’s not much of an issue at all.
I tested the top of the line World Cup model, which comes with a pretty natty selection of kit for the money. E13 provides both a set of carbon fibre cranks and a pair of LG1R+ wheels, the latter shod in tough, grippy and predictable Maxxis Minion DHR II tyres in sticky 3C rubber and dual ply sidewalls.
SRAM manages the stop and go business with a downhill specific 7spd X01DH cassette and shifter, and four piston Code stoppers with 200mm discs at either end. The former works flawlessly with a tight range that’s sufficient for race use and the latter provides oodles of stopping power, even if the lever is a bit indelicate to the touch as well as feeling somewhat spongy.
There’s a direct mount Renthal 50mm stem and 780mm wide carbon Fatbar, while Commencal provides its own seatpost and saddle.
Suspension is controlled by a RockShox Vivid R2C2 coil shock at the rear and an air sprung Boxxer World Cup with a sealed Charger damper. The Vivid allows independent high and low speed rebound adjustment as well as compression, while the fork gets just rebound and compression. Compared to their main rival Fox that means fewer knobs to twiddle, but more importantly they aren’t quite as polished when it comes to the flat out damping refinement of the latter’s top line offerings.
While the Fox units get on with taming the bumps unobtrusively, the RockShox items let you know when they’re working hard and there’s definitely more flex and twang from the ageing Boxxer chassis than from a Fox 40, though it’s not too much of a hindrance when it comes to pointing the bike where you want it.
A sucker for punishment
That said, haul the Supreme at full tilt into the gnarliest, roughest terrain you can find and the capacity of the rear end to swallow up punishment is gob smacking. It treats the most intimidating of rock sections like a glutton at an all-you-can-eat buffet; the high pivot giving the feeling that the bike opens up like a set of jaws to devour the biggest of hits, wipes its mouth and move on.
The lack of pedal kickback adds to the feeling of isolation from the bumps and, rather like a toddler that’s being ignored, I started trying to provoke a reaction by taking ludicrously rough and fast lines in an ultimately unsuccessful attempt to unsettle it. It’s true that the change in wheelbase length as the suspension compresses is definitely noticeable, but for the most part it’s positive, with the bike settling into a rearwards biased weight balance and keeping the head angle kicked back and the bike feeling calm.
Less positive is the sheer amount of drag the idler introduces into the drivetrain. Pedalling it along flatter trails is distinctly unrewarding to the point that I simply didn’t bother and stuck to the steepest, toughest and roughest I could find — a luxury not open to anyone doing a race season.
It’s an issue compounded by the rather substantial 17.4kg bulk of the bike too. While it’s not too much of an issue on pure descending capability where the weight helps it plough through, it’s inevitably more tiring to wrestle about than composite framed rivals that are nearer the 16kg mark.
The lack of reach is also noticeable at speed where you feel less in the bike than on it. Commencal may well have done this to try and keep the overall feeling of the bike more agile despite the muffling suspension action, but it’s more of a hindrance when you want to stop playing about and start really charging. Happily, an updated V4.2 model for 2017 that cures this very issue has recently been announced, with a reach that’s 23mm longer in a Large. That bike also has the suspension linkage tweaked and lightened, and the top-line bike comes with Fox suspension as standard.
As a bike made for going downhill, the Supreme is mighty impressive. The innovative suspension design delivers when it comes to laughing off the most chaotic tracks you can find and it offers really impressive kit for the money too.
If you’re all about pure gravity performance and pedalling is something you only do to get moving, then it’s superb. If your usual riding includes a bit less plummeting and a bit more contouring then it might turn into hard work quite quickly. That said, despite there being excellent discounts on this bike at the moment we’d be tempted to wait for the updated bike. I’m pretty sure that the Fox suspension would polish that bump performance further, while more space to move on the bike as well as less weight are all extremely welcome things.