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@Linc
I haven't really unleashed the geek on you guys yet so far this build so here's some info on some background studies that I've been doing on the side.
The main difference between this build and the last wooden frame is the thickness of the tubes, all in the name of reducing frame weight. However, at less than 3mm thick in places it worries me that the frame may be too fragile. I've done the calculations to convince myself that the overall frame will be strong enough and stiff enough to perform well (similar to other high performance frames) but side impacts on the tubes are harder to check and there are no standards that give any tests or requirements for impact resistance. We've done some FEA modelling (computer stress analysis) to check this, using conventional steel and aluminium tubes as benchmarks for 'impact resistance', but the orthotropic and highly non linear nature of the wood makes the analysis difficult and the results dubious.
So, i made a test sample. 2mm thick Ash with internal stiffeners
The tube was very fragile before the stiffeners were fitted but felt very robust once glued together and only slightly heavier than a Columbus Airplane alu top tube.
I set up a highly technical test rig with a G clamp and my bathroom scales #backyardengineering
Crank puller taped to the G clapm to apply the point load!
