StoneWeave: Why carbon?

04.12.2023


We at Coh&Co are quite focused on understanding our role in a new urban mobility landscape. Our mission is to get more people out riding their bicycles because we believe that riding to work is not only more environmentally friendly, it also makes for a happier healthier commute. Our cities today, so filled with the hustle and bustle of morning traffic should look forward to a morning and evening procession of cyclists with bells instead of horns and with a smile instead of a scornful grimace.

A commuting life

While this may sound idyllic cycling to work can indeed not only reduce the CO2-footprint of the urban commuter, it can also reduce health costs and there is no doubt that a bit of exercise before and after work is a great way to relieve stress while improving our urban backdrop. Part of the Coh&Co ethos is therefore a unique ride that is intended to make the experience playful and versatile. Be it transporting your kids through town on a VeloSled or zipping through city streets on an Erik urban; be it with the help of a motor or with pure pedal power, Coh&Co bikes are intended to provide a great lifestyle experience in an urban outdoor context…

So why do we design so many of our bicycles from carbon and basalt fiber composites?

What makes StoneWeave strong?

Fiber composites like carbon fiber, basalt fiber and a broad assortment of other reinforcement fibers offer some great performance advantages in comparison to traditional frame materials. First off is the issue of weight. We reinforce our laminates with carbon fiber and that means that we can produce a frame with unparalleled stiffness and strength per kilo. Carbon fiber is one of the strongest and stiffest materials known to man and when toughened with a supporting mineral fiber like basalt it can also become one of the toughest materials for the job. Carbon may be strong and stiff and therefore we don’t need to use a lot of it – that means a normal carbon laminate is very thin, and despite the structure having a global strength and stiffness allowing it to do a great job as a bicycle frame material it will be fragile if damaged locally. This is one of the reasons we add supporting fibers to make the tubes more robust. We do this not just by adding carbon fiber but also by adding additional mineral fibers such as basalt-based fibers. Bulking up our laminates may introduce a bit of weight but it does so at great benefit to the frames’ ability to withstand the punishment of everyday life on a city street. We are not trying to produce the lightest frames on the road, but we do want to make the best bikes and just to put this in perspective our VeloSled Family’s carbon frame weighs in at around 5 kilos and we have tested them to well over 400 kilos (wheels and bicycle components limits practical use to around 200 kilos full up!) of load… If you think of a typical car like a Tesla Model 3 weighing close to 2 tons and only being able to carry about 950 kilos (a weight to load ratio 1:0.5 including passengers and payload) then our StoneWeave frames offer an impressive weight to carrying ratio of up toward 1:10.

Mother relaxing in the front bed of VeloSled Anna cargobike while talking to her child

Carbon and carbon

We are not done yet! While carbon fiber may be strong and stiff and when combined with our basalt fibers it becomes tough, it also has some other characteristics that make it well suited for urban living. While most metals suffer from corrosion and weld fatigue, our composite frames do not corrode. Now, someone reading this will immediately point out that the metal components attached to the carbon WILL corrode and that they may even do so faster than if they were left to their own devices on a completely metal frame – BUT that is precisely why we have made all the metal components on our composite frames modular! Dropouts, headsets, and bottom brackets can all be replaced and refitted to ensure a long and prosperous life of city riding. Additionally, our composite frame material provides the essential spice that gives these models their lively and responsive ride quality.

So, what's the catch?

We believe in working towards a better world and while we love our StoneWeave bikes we also need to be truthful and point out that the CO2 footprint of carbon fiber is much higher than that of a traditional metal frame material. We do however believe that when one factors in added lifecycle and performance benefits and seasons it with a unique riding experience, not to mention the design freedom afforded by these materials utilizing these carbon-intensive materials is a very justifiable investment in resources – especially if it helps get more people out and pedaling. Coh&Co also utilizes a unique deconstructable epoxy resin system that allows us to reclaim frames at the end of the product life cycle. I want to point out that this means that these frame materials, carbon, and epoxy can be recycled but the primary frame material is still virgin material. Taking this even one step further we are looking to introduce second-generation materials into our new Siggi folding bike next spring. This will be the first time we open the door to using recycled carbon fibers! Recycling our laminates is a low-energy process that involves chemically deconstructing the epoxy into reusable elements and then rinsing the fibers with a washing agent to prepare them for second-generation life. Recycling carbon fiber and mineral fiber composites has historically been done by pyrolyzing (burning) the item which is to be recycled. While pyrolization does free the fiber from its epoxy matrix, it does so at great cost consuming lots of energy and degrading the material often resulting in fibers with mechanical properties that are only a fraction of that of virgin fiber – with a deconstructable resin technology we retain the mechanical properties of the fiber as well as the resin, thus providing a unique material for a second generation lifecycle.

So in summary, when we combine our long-lived well-riding composite frame material that we call StoneWeave with a recyclable material technology we open the door for a circular cradle-to-grave frame technology that we are proud to bring to the urban streets.

Experience the amazing strength and durability of our StoneWeave frame technology, with this week’s Tuesday Deal on a limited snow-white VeloSled eFamily. Click the button below to learn more.

Siggi | Folding e-bike

32% Off

The new folding bike Siggi is live on Indiegogo. It is the perfect combination of performance and convenience with an elegant fold.