Restricted Growth project update - April
Building, shipping, waiting
Our original plan had been to build two frames for fatigue tests. We ended up building an extra frame to hopefully accelerate the testing process given the long shipping times to the testing laboratory in Germany; four months ago, shipments to Germany took four days, now they take 4-6 weeks. Suffice to say, the frames are currently in a warehouse in Dortmund waiting to have their paperwork stamped.
Each box contains prepared tubes for a bike frame.
We were really pleased with how the sample frames came together and remain cautiously optimistic about their prospects during the testing process. We have built many prototype diamond shaped frames in the UK but relatively few step-through frames, so this was an opportunity for us to refine some of our processes in preparation for production.
The first of three sample frames being prepared by our in-house frame builder, Robert (affectionately known as “Keen”).
We are hoping to have initial test results back in four weeks. Depending on the outcome, we’ll either be preparing to build production frames or altering the design and sending more test frames to Germany. We’ve run Finite Element Analysis (FEA) on the frame designs which allows us to predict failure points using computer modelling. However, once steel is welded its properties change and FEA becomes trickier, hence we may need to produce more sample frames for fatigue tests.
Because Finite Element Analysis (FEA) is in its infancy on welded steel frames there is limited computer modelling we can do to anticipate real-world test results. FEA is however very reliable on aluminium frames meaning we get much closer to the final design without too many iterations for real-world testing.
The first two sample frames ready for shipping!