Bamboo Bike Frame Deflection Strength Test
To comply with Australian Standard AS/NZS 1927:1998 a bike frame has to undergo the following test: a) Anchor the rear wheel axle attachment points. (b) Apply a force of 890 N to the front axle attachment point towards and in line with the rear wheel axle and from the deflection reading compute the energy absorbed in joules. (c) Should the energy absorption reading at 890 N be less than 40 J increase the force until this figure is attained. The test apparatus I devised consists of a long clamp, some bathroom scales, a turbo trainer, and a bunch of spacers to make it all fit and stay put. In this video I preload the jig to flex the frame by 4.4cm, which is the equivalent of 40Joules, based on the equation: Work(J) = Energy(N) x Distance(m) 40 = 890x0.044 It actually took a larger load than 890N (90.7kg) - it maxed out the scales, which stop at 135kg. The frame seems to have survived with flying colours. I'm yet to do a post-test inspection, but heard no cracking or breaking during the test.