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Foto / Video Story

  • GET READY TO GRAVEL

    THE »GRAV KARL« GRAVEL BIKE PROJECT

August 2020, the weather is at its best and people are out enjoying riding bikes. As we are evolving in a fast-paced world, and our everyday life is facing a worldwide pandemic, we thought an enjoyable way to come back was to have some fun, build a gravel bike and launch our new SR SUNTOUR GVX gravel fork.

We decided to take the time to build a “local” gravel bike so we called Portus Cycles, a steel frame builder from Germany. As soon as the idea took seed, other partners got involved such as the gear box manufacturer Pinion, Gates for the belts and crankset, Hope for the wheels and stem and Vecnum for a nice, clean dropper post.

The whole process took two days, from cutting the tubes to powder coating the frame and getting the bike assembled. The process began with drawing the frame on a 3D software design tool using the dimensions you choose, HT angle, ST angle, tyre diameter, BB drop, wheel size and so on... Once the drawing is done, the tubing cutting can start. Then jigs are used to tightly fit the mitering, which is called notching in the frame builder’s world. As the parts get assembled onto the jig, a first preview appears and shows how is the bike looking with the selected angles and the different tubes in place.

Once the tubes are correctly aligned, the braze welding process can start. From the bottom bracket to the chain stay, welding the joints makes the magic happen, as you realize a bike frame is coming to life.

The raw frame is now a real thing. It is then taken to the sand blasting unit to get rid of any irregularities and to get it thoroughly clean before the last step, the powder coating. Enjoy the building process through our video and pictures and get ready to gravel.