The track walk dust has just settled at the Lourdes World Cup, but the action just stepped it up a notch or two with the release of Commencal's all-new Supreme V4 bike. A couple of years in the making, it breaks a few molds in the name of delivering where it counts the most, at least when you consider what's going down here later this week - racing.
Commencal's first objective with the new V4 was to deliver a speed weapon. The concept of the high pivot had been on chief designer Nico Menard's mind for quite some time, and he fought long and hard to get the company to commit to testing it out. Despite getting some funny looks upon presenting the first protos, he persisted - and soon enough, people didn't want to hand the test mules back. Commencal knew they were onto something.
The new suspension layout also gave Commencal the opportunity to revise the leverage ratios. More progressive than the V3, they also added 20-mm of travel to provide that extra bit of forgiveness needed when you're going out-of-control fast down rougher and rougher tracks. It wouldn't be completely far-fetched to say that this bikes appears more than perfectly suited to the track on offer here in Lourdes this weekend...
An interesting aspect of the new bike is the multitude of adjustability features. By swapping out head tube inserts you can adjust the reach by 20-mm (that's almost a full frame size in many cases), and replaceable dropouts let you play with chainstay length but also BB height without affecting the head angle (the headtube inserts exist in different heights as well).
In terms of geometry, the big departure from the V3 is the chainstay length. Because of the high pivot placement and the rearward wheel path, there is significant chainstay growth as the suspension cycles through travel. For this reason, the static chainstay length is 430 or 435-mm, compared to 447-mm on the V3. Other numbers are fairly close to the V3, just a little slacker at the head angle. Talking to the riders, the bike is apparently a riot to ride - stable yet fun, and very fast through the rough stuff. It'll take us a while to report back with actual ride impressions though, as the V4 is only scheduled to become available after summer.
Stay tuned as we'll be seeing plenty of the new V4 in action under the Commencal/Vallnord riders this week - catch more information below to get all the details too!
Press Release:
The 4th generation of the Supreme DH V4 pushes all possible limits. Reinvention.
We had to find new ways to offer our riders even more efficient bikes with more innovation...Our goal was to create a frame that goes faster. A frame that doesn’t lose speed, but generates it. Today, with the DH V4 we can say that we have got there.
This wasn’t easy, a lot of development, time spent thinking and rethinking, but THE final solution for our SUPREME has been found.
Design. Having a ‘carte blanche’ gave us a chance to put many possibilities to the test, but also there are big responsibilities. Finally we received the approval of our best riders and all the rest a like.
Genesis
Ideas burst forth every day at the office. Sometimes they’re wacky, sometimes there’re genius but they are certainly never boring. The idea of creating a bike with a High Pivot Point (HPP) appeared crazy to many in the office. Another engineering concept...
While technically this concept has very interesting advantages, it is also very aesthetically risky. At COMMENCAL there is no compromise. A bicycle must look beautiful AND perform. Two significant criteria.
Max COMMENCAL is a passionate man, he never closes the door to new challenges. We got the challenge we asked for.
So we went with this and we tested the concept on a basic enduro frame with 160mm of travel and 650b wheels.
A little shunned initially for being ‘rough around the edges,’ finally the HPP was unanimously fast. For an enduro bike this was an unsuspected capacity, a real step forward as we hope for every time we create a new platform. We shall continue in this direction.
This HPP frame allowed us to understand a totally different functionality compared to a conventional bicycle. For example, being able to test several anchoring solutions of the idler with totally different settings allowed us to imagine the design of the SUPREME DH V4.
Contact System Part 1
One cannot deny that the kinematics of the SUPREME DH V4 have changed radically. Still based on a single pivot and linkage system to manage progressivity, its high pivot point and the position of the idler make all the difference.
Why a high pivot point? To obtain the correct rear wheel path which avoids stumbling over obstacles and carries a greater speed through rough sections. It goes back to a fundamental concept for downhill – speed.
It is however, not without its drawbacks. Using such a high pivot without an idler would generate a lot of chain tension and the bike would be impossible to ride because of the kickback excess.
Kickback is not only annoying for the rider, it also has an impact on the suspension during pedalling and while riding very rough trails.
This is where the idler comes into play. It counteracts the chain effects. As stated earlier, our first prototype was a great help to select the optimum position.
Theory is one thing but it then has to be validated in the mountains.
Specifically, by setting the idler on the swingarm in a precise place, we wanted to create an anti- squat value high enough to be lively when needed, out of a corner for example.
Contact System Part 2
A downhill bike must pedal well; it must be especially effective from the first pedal stroke... And that’s what we’ve got. Whichever cog is being used, its settings will not be affected. A big advantage.
However, a relatively strong anti-squat value is often incompatible with a low kickback value.
The kickback, stemming from the chain tension, is detrimental to the functioning of the rear suspension.
This unpleasant kickback transmits how the bodyweight affects the suspension via the chain tension, which effectively prevents the suspension from working freely.
It was therefore fundamental not end up with too high a value.
Thanks to the specific positioning of the idler, we could reduce kickback significantly. Thus the operation of the suspension is not affected.
With a rear wheel path which facilitates the work of the suspension, it was necessary for us to revise our way of thinking with regards to the leverage ratio of the SUPREME.
Very close to the META V4 in its shape, this allows an excellent grip at the start of the stroke, which then allows an excellent support throughout the middle range of the travel.
Contact System Part 3
A high pivot point avoids the unnecessary consumption of too much travel, which is an important parameter.
Figures are often used as references; the SUPREME DH V4 relies on 220mm of travel. Why so much? Think back to our original objective: speed.
It all depends on the track. The fastest lines of the track are not necessarily the cleanest. Also, to see ‘huck to flat’ in a race is not uncommon and to bottom out in these sections would slow the bike down.
So you have to see the last 20mm as a solution to prevent bottoming out hard but also see it as a barely reached zone.
The first 200mm of travel is actually very close to what is currently found on a SUPREME DH V3.
Kinematics would be nothing without an efficient rear shock. Each manufacturer has been involved in developing a setting to work in perfect harmony with our frame.
Modular Geometry Part 1
Since the first COMMENCAL SUPREME DH, we always wanted to offer bicycles with modular geometry.
Often seen as the Formula 1 of mountain biking, downhill bikes need to adapt to the characteristics of each track and to every riding style. Pietermaritzburg, Fort William, Mont Saint Anne, Vallnord... So many different tracks all demanding the best possible balance.
Within our DH team for example, we have Thibaut Ruffin and Rémi Thirion, two riders with two very different requirements. Two different people to satisfy, along with the rest!
We have therefore decided to create a highly adjustable geometry through a set of specific dropouts and headtube cups. Thanks to them we can adjust the chain stay length, the bottom bracket height and the ‘reach’ without affecting the angles of the bike.
Positioned at 62.5°, the head angle is fixed. It’s a value that is universally recognized in the COMMENCAL/VALLNORD DH Racing Team. Rather than offering a useless adjuster, we opted for a reach setting in order to be able to adjust its position perfectly according to the rider’s preferences, and the track. It can therefore be adjusted between -10/-8/-5/0/+5/+8/+10.
Modular Geometry Part 2
The chainstay length was the subject of our attention. We managed to get a shorter chainstay length than usual, despite the high pivot point and the rearward wheel path.
The idea is to keep a good balance of the bike and avoid it getting too clumsy. If you compare the chainstay lengths of the SUPREME DH V3 and SUPREME DH V4, the difference seems huge (447mm vs 425mm). But on the SUPREME DH V4, the chainstay length increases through the travel, this difference lessens.
It is still shorter on the SUPREME DH V4 (450mm rather than 457mm) to maintain a lively bike. This value is really useful in understanding the bike. The HPP prototype had an even higher pivot point but we decided to lower it on the SUPREME DH V4 to find the best possible balance between the operation of the suspension and the liveliness of the bike.
Available in four sizes (S, M, L and XL), the SUPREME DH V4 covers a wide range of riders and the geometry is directly derived from the work with our own talented team.
Frame Construction Part 1
Over and over again, we persist with aluminium, our tubes are made of 6066 aluminium making the design of the SUPREME DH V4 very neat. Once again we demonstrate that an aluminium frame, when done properly, has many benefits.
First of all? Reliability. That is and will remain our priority. Pivot points are re-machined after welding, we have almost an obsession when it comes to cutting the tubes for a perfect fit. Axles are made of aluminium 7075 T6 and we use oversized bearings which prove to be reliable on a long-term basis.
Ultimately, it’s this careful construction that gives this frame absolutely everything over the rest of the field.
With a 267mm eye-to-eye shock length, it seemed difficult to maintain a relatively low centre of gravity. With a lot of hard work, we got there. The result is a compact system that reduces the feeling of the mass when riding.
Faithful to the single-pivot, a linkage and a rocker are used to control the leverage ratio. This change from the SUPREME DH V3 and its ‘4 bar linkage’ is explained by a more precise control of the leverage ratio and an optimized stiffness of the frame.
As with our other platforms, the frame stiffness is an important parameter and we do not want it to be too stiff.
Frame Construction Part 2
A certain amount of suppleness allows for more grip and tolerance. This has nothing to do with the riders’ skills; World Cup riders demand it for their frames too.
Never has a frame at COMMENCAL had more attention, we pushed every detail and finish even further. So, we can name the fork bumpers that integrate the cable path, the fender, the ‘roller cover’, the double density seat stay protector and the cable guides at the exit of the rear of the swingarm which prevent any inadvertent change of gear... Well, you guessed it, it has been pampered to perfection.
Designing the SUPREME DH V4 was a real challenge.
Convinced of its performance, we worked to make the idler as discreet as possible, hiding it in the swingarm. The final version fully satisfies us. The first raw finish HPP seems so long ago...
“Be beautiful and ride fast.” A successful objective.
4/9/2015 9:06am
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