Aspects of the Requirements of ISO 15263.4 and the Design and Development of Bicycle Racks

Abstract

There is currently interest in developing safety standards for bicycle racks for cars. A draft international standard (ISO 15263.4) has been developed. However, there have been many objections to the proposals and a redraft has been made. This study aims to investigate a part of the standard that involves performing deflection tests on bicycle racks.

The research evaluates the deflection tests, considering how representative and repeatable they are. The results are compared to predictions made using FEA software and calculations of stress and deflection. The required deflection tests were performed on a Pendle Bike Rack.

The results show that the Pendle TBM 3 rack would pass the deflection test part of the draft ISO 15263.4 standard. It is demonstrated that by measuring strain with strain gauges and calculating the stress, the rack operates within 35% of the ultimate tensile strength of the material. The effectiveness of FEA software is demonstrated by achieving similar results from FEA simulations to the experimental data. The application of FEA is explored, using it to simulate changes to the design of the rack to make it stronger and lighter.

The discussion shows that the draft ISO 15263.4 standard needs further development. The draft ISO 15263.4 standard doesn't address issues of fatigue failure, could focus more on ensuring safe use of the product and is more suited to certain types of bicycle rack. In this thesis it is suggested that further drafts of the ISO 16263.4 standard should incorporate different testing schedules for different types of bicycle rack. Tests for racks that are bolted onto a tow ball should differ from tests for racks that strap onto the tailgate.