Bamboo Bike Frame Deflection Strength Test #2 - Daisy

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 in order to get the 4.4cm of deflection. I'd say it was in the order of 150-170kg. The frame's passed with flying colours and there's no signs of damage from the test.

Category:

Sports

Tags:

• bamboo
• bike
• strength
• test
• frame
• cycling
• testing
• australian
• standards

[carcano38]

This is more of a test for the fork then the bike frame.

[Rice4Lif3]

where did you get your bamboo from??? it looks soo clean compared to the one growing my ayrd

[HariVIyer]

hmmm...will it blend?

[ELPpes]

Work(J) = Load(N) x Distance(m). The load is in Newtons, not the energy. But this equation would be ok if the load applied load remains constant. In this test, the load is not constant because it comes from 0 to 890N. So you would need to use the average load. The right equation would be as follows: Work(J) = 1/2 x Load(N) x Distance(m). So, to achieve a strain energy of 40 J, the deflection would be about 9cm and not 4.4.

[JonasTheSniper]

@Numeriwar "Should the energy absorption reading at 890 N..."

Not "energy absorption of 890 N...", AT 890 N, meaning that when 890 Newtons are applied the energy absorbed be less than 40J....

[Numeriwar]

Energy is not in newton...

[dpsrush]

nvm i just watched the how to make a bamboo bike video xD

[dpsrush]

what do u use to connect the bamboo to the metal sockets, glue?