We Sent Our Bamboo to a University Lab — Here's What the Numbers Said
People often ask the same question before they build with bamboo: will it actually hold up? So we did the obvious thing — we sent our bamboo to an engineering lab and had it tested to a recognised international standard.
Context
Bamboo is a naturally occurring composite: longitudinal cellulose fibres set in a lignin matrix, with fibre density increasing toward the outer wall of the culm. That structure is what gives it a high strength-to-weight ratio and the natural vibration damping that makes a bamboo frame so comfortable to ride. But "naturally occurring" means every culm is slightly different — so the only honest way to talk about strength is to measure it.
What we did
In partnership with Swansea University, bamboo culms supplied by Bamboo Bicycle Club were tested to BS ISO 22157:2019 — the international standard for determining the physical and mechanical properties of bamboo.
- 14 culms were sent (labelled A–N); the 6 highest-quality specimens were selected for testing.
- Flexural (three-point bending): load applied at a node over a 300 mm span.
- Tensile: 180 × 8 × 3 mm specimens with epoxy-attached tabs, pulled at 2 mm/min.
- Compressive: tested per the same ISO standard.
Verified outcome
| Test | Property | Result | |------|----------|--------| | Flexural | Young's Modulus (avg) | 6,402.93 MPa | | Flexural | Ultimate Flexural Stress (avg) | 70.96 MPa | | Tensile | Ultimate Tensile Stress (avg) | 84.34 MPa | | Compressive | Ultimate Compressive Stress (avg) | 57.7 MPa |
The bamboo showed little to no plastic deformation — it carries load and then fails cleanly once the maximum bending moment is reached, rather than slowly bending out of shape. Results varied between specimens, exactly as you'd expect from a natural material with differing diameters, wall thicknesses and natural defects.
In plain terms: tested to an ISO standard, this bamboo is comparable to mild steel in strength — while weighing a fraction as much. That weight advantage is the whole point of building a frame from it.
Why it matters
This isn't a marketing claim — it's a measurement, taken in a university lab to a published international standard. It's why we're comfortable putting people on bamboo frames they've built themselves, and why those frames keep going: many built in 2012 are still ridden daily.