Research initiated by Motor Wheel Service - one of the leading independent distributors of truck and trailer wheels throughout Europe - has found that commercial vehicle wheels operating on spider and star-shaped hubs are suffering untested load stresses which are causing cracks and halving life expectancy.
At present all quality wheels are tried and tested to European Tyre and Rim Technical Organisation (ETRTO) standards on a circumferential hub with a continuous contact diameter, which is universally acknowledged as the main criterion by the Association of European Wheel Manufacturers (EUWA). However, the introduction of non-circumferential hubs, which give only partial contact between the axle and wheel, is causing localised stresses in the wheel that are almost twice as high as the industry approved full contact hub.
The repercussions of the research will be numerous. Operators will be required to contact hub and wheel manufacturers as products originally replaced or refunded under warranty may no longer be considered if the product is shown to have operated on a spider or star shaped hub. In addition, due to the differing characteristics of the various hub shapes, interchangeability can be affected as mounting those wheels on hubs with yet another shape can further drastically reduce the attachment area leading to increased surface pressure and an undefined attachment of wheel to hub.
Vehicle maintenance, service schedules and MOT tests will also need to be more rigorous, with the company suggesting that operators contact VOSA and the main CV organisations for their interpretation of the findings. The investigation has been carried out by one of the world’s leading CV wheel experts, Dr. Sundararajan of Wheels India, and forms an integral part of Motor Wheel Service’s ongoing wheel safety campaign.
The results will be presented to Mike Penning, Under Secretary of State for Transport, and senior personnel at the Freight Transport Association (FTA); Institute of Road Transport Engineers (IRTE) and Road Haulage Association (RHA) by John Ellis, Managing Director of Motor Wheel Service.
Mr Ellis said: “The research is undeniable. Wheels designed and manufactured to ETRTO standards are being placed on axles that are non-standard, or non-circumferential. This is leading to the early fatigue of wheels, primarily displayed as cracks, approximately halfway through the lifetime expectancy. We do not know how many vehicles are operating on UK roads with spider and star shaped hubs. It is now up to VOSA and the main CV bodies, who I suspect are completely unaware of this problem, to ascertain the scale of the issue and exactly how it should be handled.”
“Time and time again we have told people that there is a problem in the marketplace exemplified by a sharp increase in the number of cracked wheels we are witnessing. I suspect we will see a correlation with the increasing use of these hubs. The wheel safety issue is still a number one priority and we will continue to push for further clarification of testing and unregulated sellers. In the interim I urge any operator concerned with the findings to contact VOSA, the manufacturers or MWS and we will help resolve this issue,” concluded Mr Ellis.
The Department for Transport has stated that it will undertake independent testing to verify the research. During a meeting between Mike Penning, Parliamentary Under-Secretary of State for Transport, John Ellis, and Paul Goggins, Labour MP for Wythenshawe and Sale East, it was also confirmed that VOSA will look to ascertain the number of vehicles operating on non-standard hubs.
Mr. Ellis said: "The Minister listened astutely to our findings and stated that the DfT will undertake published, independent research and instruct VOSA to ascertain the scale of the issue. No timescale has yet been set, but we will continue to liaise with government and assist wherever possible. I would like to publicly thank the Minister for listening to our research and immediately instigating decisive action. His unequivocal commitment to safety is mirrored by Paul Goggins MP, who has backed our wheel safety campaign and who has continued to push hard to get us to this juncture.”
Paul Goggins added: "This is a very positive outcome to the dialogue we have been having with the Minister. I commend John Ellis for his determination to get to the bottom of this issue. Road safety is an absolute priority."
Motor Wheel Service can be contacted by ringing 0161 908 1023, e-mailing info@xlitewheels.com or by visiting www.mwsdistribution.co.uk.
Top photo: John Ellis, Managing Director of Motor Wheel Service, with a damaged CV wheel; Finite element Analysis regular hub: an FEA simulation showing stress patterns on a wheel created by a circumference hub and Finite element Analysis star hub: an FEA stimulation showing stress patterns created on a wheel by a non-circumference hub.