The results are in!
The three frames completed six gruelling tests, putting them through hundreds of thousands of cycles to find the weak points of the structure.
We found one - the bottom bracket shell (the tube at the bottom of the frame into which the bike's cranks fit, allowing you to pedal); however one of the advantages of a steel frame is it doesn’t fail catastrophically. Carbon fibre can appear fine one moment, and break the next, barely without warning. Steel however begins to show signs of fatigue as the material bends and creeps, often manifesting as cracked paint. When the tubing does crack, it will generally begin with a hairline and slowly work its way through the material.
For this reason, steel is a fantastic material for certain applications – like trains where hairline fractures give you early warning signs of failure - and travel chaos!
ISO4210 City and Trekking - Falling frame impact test
We are now building two final test frames, with changes to the bottom bracket, to double check clearances (space between components when fitted to the frame). In the meantime we’re warming up conversations with the powder coaters based in Ludlow – meaning we can deliver/collect the frames with our cargo bike.
Next month, we’ll update you on exactly when the bikes will be available – expect it to be this summer!
As always, if you have any questions or would like to get in touch please email.