In this post we are going to take a look at Devinci bikes. Devinci – Wilson Carbon to be more specific. Recently I had an opportunity to try it out for the first time and instantly fell in love with it.
Devinci introduced its modern Wilson frame model in 2011. The frame has an 8.5-inch travel and a suspension system developed by Dave Wiggle with a hinge located around the axis of the rear wheel. Same year, the company’s management signed a contract with Canadian racer and public favorite Steve Smith.
At the “Interbike” exhibition, a version of the Wilson frame with a carbon swingarm was presented, and everyone understood that swingarm was just the beginning. The release of a full carbon frame was only a matter of time, however, Devinci’s management did not comment on this topic.
“When I first started working at Devinci, it was clear that sooner or later we would start producing downhill carbon frames,” says Wigle. “Carbon swingarm showed itself well, and we decided to take the next logical step – to make a front triangle from carbon and see what advantages it will give.”
Devinci’s engineers were no pioneers in the production of carbon frames for downhill, nonetheless, they chose most unusual approach to building a bike – the first carbon element of their new frame was not the front triangle, but the swingarm.
There are several companies today that manufacture downhill bikes with a carbon fiber front triangle and aluminum rear triangle. Manufacturers explain this by the high cost of making a rear triangle from carbon, and that it is not an easy task to make it reliable and aesthetically pleasing at the same time.
So why then in 2011 Devinci started from swingarm. The fact is that engineers wanted to better study the effect of the materials used on ride quality, and in addition, the use of carbon fiber swingarm allowed them to achieve the required rigidness of the rear triangle. Required rigidness of the rear triangle is exactly how much a downhill frame needs, no more, no less.
Most common questions that are being asked about carbon frames are, of course, questions about weight. People are interested in how much lighter the carbon version is compared to aluminum model. An equally important question is about the stiffness of the frame. Moreover, under this term people understand that elusive sensation of riding, which gives each frame its own unique characteristics.
It is known that carbon and aluminum versions of the same frame behave somewhat differently and require different suspension settings – all because of the different properties of materials. This is why Devinci engineers decided to leave aluminum chainstay on Wilson Carbon, which is reasonable – carbon would weigh less only by a fraction but will be a lot more expensive. In addition, chainstay is being constantly hit by the chain and rocks from under the wheels, which is another argument in favor of aluminum.
“You should not think that there can’t be too much stiffness. We tried to find a middle ground when it is not too much or to little, but exactly as much as necessary. ”- Dave Wigle.
Vast majority of carbon frames are made by using hydroforming. First they make a steel mold, then place sheets of carbon fiber inside and form it under pressure using a special elastic chamber made of nylon or latex. Sounds simple enough, but in practice, manufacturers often face certain difficulties.
Despite the fact that the hydroforming technology has been successfully used for many years, it has its drawbacks that become noticeable when it comes to manufacturing complex shape parts.
To make a strong and reliable carbon frame, it is necessary to precisely and evenly distribute the pressure inside the mold so that there are as few empty spaces as possible in walls of the finished product.
This is hard to achieve in narrow spaces and bents by using this method, so Devinci engineers had to use ingenuity. The solution was to use special silicone inserts with two carbon spars in places where down and top tube meet with head tube.
These inserts allow to evenly distribute the pressure in hard-to-reach places in the elastic chamber. As a result, thanks to the absence of empty spaces in walls, the frame becomes a lot stronger.
A longitudinal section of the test frame showed that the walls turned out smooth and evenly molded, and this applies not only to the top and down tubes, but also to the places where they connect with head tube and bottom bracket.
Split Pivot Suspension
Although the new frame has a carbon front triangle the suspension system remains the same as on the aluminum version. It’s called “Split Pivot” developed by Dave Wigle. Dave and other Devinci engineers have spent more than one year developing a bike that could handle bumps better than almost any other bicycle. And I must say, they did it. So for Devinci there was no point in creating a new carbon frame from scratch – it was enough to make a front triangle from carbon for the”Wilson” model.
The Wilson rear suspension system consists of four basic elements. A carbon swingarm, a hinge located around the axis of the rear wheel (which is called the Split Pivot), a link of the floating brake (in this case, its function is performed by the chainstay) and another link for suspension.
The rotation axis of the carbon swingarm is located fairly high – this is done so that the rear wheel, when the suspension is working, goes backward. According to the manufacturer, the Wilson suspension system provides at the same time excellent handling on sharp edges of uneven terrain and the ability to effectively pedal, and this is probably the most important thing for a downhill bike.
The hinge connecting the swingarm with the chainstay is located around the axis of the rear wheel, and the brake caliper is attached to the chainstay as well – this gives the effect of a “floating” brake and minimizes the effect of braking on the suspension. So, even when you are breaking, the suspension continues to work.
The first thing that catches your eye when looking at the Wilson frame is the hinge located around the axis of the rear wheel. However, there is a more important element in suspension – a link that is almost invisible from the outside, which sets in motion rear suspension.
Thanks to this link Wilson frame owes its excellent suspension performance thanks to this link. This element, milled from a single piece of aluminum, rotates around the bottom bracket on two massive closed bearings. This link has a chainstay hinge and eyelets for fastening the shock absorber.
“This link is the heart of the frame,” explains Wigle. – “It provides the stiffness in connection of the chainstay with the front triangle of the frame and determines the behavior of the bike when riding on uneven surfaces.”
Experiments with the size and shape of this link allowed Devinci engineers to achieve desired performance of the suspension.
It is considered that the stiffness of the rear triangle of the frame is determined primarily by the rigidity of the seat stay and chainstay. In a way this is true, however, the link described above also plays a significant role here. Devinci engineers’ task was not to just connect the chainstay to the front triangle of the frame with a massive piece of aluminum and thereby ensure maximum stiffness, it was to ensure exact amount stiffness as needed. The shape and size of the link is not at all accidental. “while experimenting with the link, we changed both the stiffness of the frame and the characteristics of the suspension,” says Wigle. In order to lower the center of gravity of a bike all heavy parts were installed as low as possible.
The efforts of the engineers were not in vain – the frame performed well on the very first race, when Steve Smith won the downhill at the Crankworx festival. The race was tough, in terms of complexity it wasn’t inferior to races of the World Cup.
It should be noted that for Steve, this race was not so much a serious competition as a kind of respite between the stages of the Cup. It is unlikely that Smith would have shown worse result on the aluminum frame, however, his first place shows how confident he felt on the new bike, which he received just before the race.
The next challenge for Steve and his new bike was the World Championships in Leogang, where the track was relatively smooth and very different from the Canadian track. Steve on a Wilson Carbon bike did not disappoint the Canadians and proved their versatility – Smith took third place, he was only 1.2 seconds behind the champion. It is unlikely that some readers will compete with Steve in the World Cup races, but we must note that Wilson Carbon theoretically allows you to do this. Not counting team colors, Smiths Wilson Carbon bike has the same frame that Devinci is selling in stores.
“Everyone says that we ride prototypes with some special geometry, but when you buy a Devinci frame, you buy exactly what I ride. This is the bike on which I participate in World Cup races. ”- Steve Smith.