Carbon Frame Tech Explained

Ribble has been synonymous with producing top quality, high-performance carbon road bicycles since they first hit the market back in the early noughties. Every frameset is designed in house, by our R&D team based in Lancashire and is custom made for us and us alone.

Every Ribble carbon frameset is engineered to go far beyond the required safety standards. We don’t just meet the benchmark - we set it. From the earliest sketches to the final clear coat, our aim is the same: build class-leading frames using the most advanced construction techniques available.

Before a frame leaves the factory, it’s put through stringent quality control and safety checks to make sure it delivers exactly what we promise — performance you can trust.

Take our flagship ULTRA-RACE carbon frameset. It’s one of the most advanced aero road frames on the market, pushing aerodynamic integration to the limit in the pursuit of pure speed. Like our endurance carbon range, it’s designed for real-world riders as well as pros, but it’s tuned to squeeze out every last watt.

Here’s what goes into the DNA of a Ribble carbon frame.

In simple terms, carbon frames are built in two main ways: monocoque or tube-to-tube.

**Carbon Monocoque ** Individual carbon strands are layered and woven into a single mould to create a one-piece structure. With no bonded joints, dynamic stress is spread evenly across the tubing, avoiding weak spots and delivering exceptional stiffness and strength.

**Tube-to-Tube ** Each frame section - head tube, top tube, down tube, bottom bracket, rear triangle - is made separately, then bonded together. This is quicker and more cost-effective to produce, but can’t match the strength, stiffness, or weight advantages of a true monocoque.

**How it Feels on the Road ** A monocoque frame resists torsional and lateral flex better, meaning less energy lost to frame twist and more of your power driving you forward - whether you’re sprinting for the line or climbing out of the saddle.

As well as being of monocoque construction, the ULTRA series of framesets also benefit from an advanced manufacturing process known as a Full EPS Inner Core System or expanded polystyrene system if you like the techy stuff.

EPS is a process whereby an expanded polystyrene internal mould is covered in latex. Individual strands of carbon fibre are then ‘layered up’ to an exacting specification over this internal construct. The whole mould is then heated to 130°, inflated and then cured. When the latex is removed it produces a perfectly smooth finish, with none of the excess material you tend to find on the inside of less advanced frames. But what difference does this EPS core make to the overall construction of a frame?

• Unlike other methods of manufacturing, the EPS process results in a frame that exhibits zero excess carbon material on the inside of the tubing. Why should this matter we hear you ask? Well, not only is the inside of the frame completely smooth to the touch, but it also eliminates any imperfections, which in turn enhances the structural integrity of each carbon fibre to create a stronger frame.
• It enables the frame to be constructed as one complete section of carbon. A monocoque frame is stronger, lighter, and stiffer than a comparable bonded frame.
• It eliminates the imperfections in the carbon layup that earlier production methods were susceptible to. Zero imperfections result in exceptional strength and reliability.

Using the highest quality carbon tubing is essential to achieving the holy grail of strength, durability, and weight. Using high-quality carbon fibre and the EPS construction technique allows us to build carbon frames using less material, without compromisng strength or the overall ride quality. And just as importantly, it results in a much lighter frame overall.

The graphic above demonstrates how various frame shapes affect airflow differently. From left to right: Round, Aerofoil, and Truncated Aerofoil tube profiles.

Aerodynamics played a key role in the development of the ULTRA-RACE, ULTRA-AERO SL R & SL. With every tube shape being analysed, dissected, and perfected in the wind tunnel and during real-world testing to enhance the aero gains experienced at speeds achievable by riders of all experience levels as well as seasoned pros. Extensive wind tunnel and real-world testing resulted in the most aerodynamically advanced and slipperiest aero road framesets Ribble has ever produced.

• **Truncated aerofoil tube profiles **- Previous generations of aero frames featured teardrop tubes which were extremely aero but less stable in crosswinds. The truncated aerofoil reduces these effects whilst providing beneficial aero drag savings.
• **Enhanced lateral stiffness **- When you stomp on the pedals, the power generated will cause a frame with reduced lateral stiffness to 'flex'. Thereby reducing the amount of power generated being transferred to forward motion. This is inefficient, so a frame that exhibits a high degree of lateral stiffness is more advantageous to overall speed and pedalling efficiency.
• It's lighter as there is less material - A monocoque frame can be manufactured to be lighter for the same amount of strength
• Provides better vertical compliance. The dropped seat stay design of the frame and profile of the tubes work mutually to absorb vibration transmitted through the frame.
• **Internal cable routing **- Cables create drag as well as looking untidy. Routing the cables through the frame removes the drag effects of the cables whilst giving the bike a super clean look.
• Internal wedge seat clamp- Instead of an external seat clamp, there is now an internal wedge mounted within the junction of seat tube/top tube.*

Above image: The ULTRA-AERO SL R's tube profiles are designed to minimise the effect the rider plays on the overall aerodynamic efficiency of bike and rider combined.

Image: The distinctive dropped seat stays that are the trademark of all Ribble's carbon frames.

Each Ribble frame feature dropped seat stays which are far from being a cosmetic affectation. Dropping the stays down the seat tube introduces vertical compliance for enhanced comfort through vibration absorption and more efficient power transfer.

Every Ribble frame incorporates several cutting-edge design features to make them faster, lighter and more comfortable.

• Precision steering- An oversized (tapered) fork steerer, headtube and fork blades stiffen up the front end for pinpoint handling during out of the saddle efforts.
• Dropped seat stays- Enhanced shock absorption helps filter out the fatigue-inducing effects of 'road buzz', keeping you fresher for longer.
• Boxed section chainstays- They ensure that the bike remains stiff for better power transfer.

Our current range of high-performance carbon road disc bikes offers more than sufficient clearance to fit the modern tyre widths that are better suited to the rigours and demands of today's road surfaces.

Tyre clearance has undergone somewhat of a revolution over the past few years and consequently, most bikes are now optimised for wider tyres that enhance ride comfort, speed and grip.

For those who wish to sample the delights of riding off-road, there's the option to choose Gravel, Hybrid, or ALLROAD bikes. These framesets are designed to accommodate a vast selection of tyres to suit all types of terrain/surfaces, offering compatibility with chunky gravel tyres as wide as 50mm.

In summary, we can say that our carbon framesets are manufactured from the best carbon that money can buy. Not only are they light and stiff but they also absorb more of the vibrations from uneven surfaces than any other carbon frame that have come before. In practical terms, this ensures you feel less fatigued when riding longer distances and on rougher surfaces. Plus, they can be built up come in under the UCI's weight limit to create a bike that will literally float up the climbs.