Erik and Mattis – two spirits forged of stone

Interview with Co-founder Paul Harder Cohen about the design of our Erik urban – and how its twin bike Mattis pushed us into the wonderful world of Gravel cycling.

StoneWeave Erik
Mattis Gravel Bike out of the city

How did you get the inspiration for Erik Urban?

A couple of years ago I remember walking along the harbor front on one of those warm sunny spring days. A girl sat on a bench cleaning her bike to rid it of all its winter grime. Our eyes met for a moment and I could see she was enjoying the sun on this first day of spring and looking forward to the promise of better weather and a ride. 

As I walked on I reflected on how to design a bike that addressed the issues of life in the city. 

An open rear triangle so that it was easy to clean, a Gates carbon belt drive so that there is no chain to grow rusty, internal gears that afford reliable performance without cleaning and regular maintenance, a composite frame that could be maintained and that wouldn’t corrode, a sporty geometry that would accelerate eagerly after halting at traffic signals…and most of all, a bike that would provide its rider with a sense of joy and satisfaction when zipping through town and going about one’s daily life. 

Born was the idea for our StoneWeave Erik, and although it would take another couple of years before Erik would show up on the city streets, the design brief was cemented on that very spring day. From then on it was a quest to design the perfect bike to make good on these lofty ambitions.


“…and most of all, a bike that would provide its rider with a sense of joy and satisfaction when zipping through town and going about one’s daily life.”

Erik Urban with belt drive

With the thoughts about Erik all evolving around urban cycling, why and how did you decide to build it up as a gravel version?

When the first Erik came out of the mold it was a wonderful moment. 

The frame was light and intriguing and it was almost impossible to contain our excitement for the next few days as we had to paint the prototype and build her up. Our then mechanic wizard/draftsman Sergio soon got to the nuts and bolts of the matter and began building up the bike.  

It took much of the afternoon to build the first bike and by the end of the day, she was ready for a test ride. In an attempt to acknowledge the efforts of the team I stepped back and insisted that Sergio take the first ride. He came back with a joyous smile on his face and immediately burst out with the words:

“We should do a gravel bike build of this!” 


 That is how Mattis was conceived on the day that Erik was born…

Sounds like you missed the goal of your own design brief…!

Exactly! At first glance, I had no idea why he thought this would be a good idea. I had done my best to design a cabriolet roadster for the urban streets and he wanted us to build it up like a tractor….. 

I appreciated his enthusiasm but I was not very flattered.

Yet, when I got out riding myself, I immediately understood what he meant. There was something lively and fun about the geometry that made me want to go and play. These composite frames combined with our proprietary StoneWeave carbon fiber and basalt technology, provide a really comfortable ride and a super sporty feel. 

Can you explain a bit more about geometry and ride feel?

The frame geometry is short, but the front end is steep while the backend is a bit more relaxed than is normal for an urban bike. This combination of angles means that these frames are really quick to accelerate off the mark and they are also great at handling. They settle into a groove at a comfortable speed while providing a reasonably upright riding position that affords a sense of security on city streets. 

Oddly enough this all works out well for a gravel bike!

Negotiating challenging terrain and gravel roads doesn’t require the fastest or stiffest frame, it requires a tactile sense of agility and a reassuring sense of smoothness that this frame does a great job of. 

“These composite frames combined with our proprietary StoneWeave carbon fiber and basalt technology, provide a really comfortable ride and a super sporty feel.” 

Mattis Gravel adventure

How about StoneWeave material technology? How does that contribute to the riding experience?

Our StoneWeave technology is unique for several reasons. Not only does it utilize the world’s first recyclable epoxy prepreg resin system; which in plain English means that we can reclaim both the fiber and the resin without burning it or chopping it up into smaller fibers. It also combines carbon fiber with basalt to allow us to build an exceptionally tough bike (read thick-walled) without becoming harsh. Basalt fibers do a great job of absorbing and dampening vibration – and that makes for a more comfortable ride, which essentially works well for city cycling as well as on gravel surfaces.

Which considerations did you have in deciding on the hardware for Mattis?

Now, even though this frame series had apparent promise for both urban and gravel we needed to do figure out a build that made sense for gravel. Urban was easy – belt drive and internal gears. 

For Mattis we wanted a lighter more traditional kit so external gears and a chain seemed to make sense from the get-go. Luckily both Sergio and I had a soft spot for 1X drive systems –  I like the wider gear spacing and simplicity for a 1X drivetrain because I feel it allows me to find the best gear quickly and easily without slipping around on an unsteady footing up a hill. Thus making it much easier to power up a hill without having to get off halfway up due to a poorly executed shift. 

We also wanted a wider set of tires so we maxed out the frame with 38mm knobby tires on tubeless-ready rims. Whereas Erik is an urban bike and fitted with double action disc brakes on cables we chose to fit Mattis with hydraulic double-action calipers and a set of Gevenalle Brifters. Gevenalle is an American brand that grew out of the cyclocross scene in Portland, Oregon. These guys make great simple, shifting “mechs” that can be easily serviced and maintained and once you get used to them you’ll fall in love.

So in that sense, the original idea about low maintenance and a sporty, comfortable riding experience seems to have transferred well from Erik to Mattis? 

I would say so. Looking back on that day in the springtime sun I’d like to thank that girl on the bench – I’d also like to thank Sergio for opening our eyes to the fun and potential that awaited in building up the Mattis. 

StoneWeave Mattis recyclable frame technology