It always lasts!

Maintaining dual tyres presents particular challenges. For example, it is often not possible to check the air pressure in the inner dual tyres regularly because the plastic or hose tyre valve extensions are either broken off or missing. 

As a result, the air pressure in inner dual tyres is often too low. This results in increased tyre wear and a greater risk of accidents. 

DEKRA has presented the dangers in a comprehensive study.

Plastic valve extensions are rigid and therefore break easily if foreign objects get between the twin tyres or if the valve extension is not guided precisely through a rim hole when mounting the outer twin wheel. They quickly become brittle and fragile due to thermal influences. If the valve extension is broken, the pressure of the inner twin tyre can no longer be checked.

Rubber tube valve extensions can only be used with rim holders. If the valve extension comes loose from the rim holder, it will rub through the rim hole and the air pressure will completely escape from the tyre. A flat tyre in a few seconds and tyre damage is inevitable.

air-flexx® combines the advantages of standard plastic and rubber tube tyre valve extensions. air-flexx® tyre valve extensions are pressureless, so there is no risk of flat tyres. On the other hand, they are flexible and of very high quality, so there is no risk of breakage. This means that the air pressure can be checked at any time.

air-flexx® valve extensions are available in different sizes for twin inner tyres, for front and single wheels with wheel covers and for spare wheels. 

The manufacturer is Glauch GmbH, Viersen. air-flexx® valve extensions are produced in Germany.

DEKRA report: more than 1,000 commercial vehicles inspected – more than half found to be defective

As part of the regular vehicle monitoring, DEKRA engineers examined 1,012 commercial vehicles (106 buses and 906 trucks and their trailers) that were equipped with at least one axle with twin tires. A total of 3,610 wheels, including 671 twin-tire axles, were inspected.

The result is extremely worrying: of the 1,012 vehicles inspected, 513 vehicles (51 percent), including 87 buses, had at least one, and in many cases multiple, complaints regarding the required inspection and filling options for the tires. 499 vehicles were without complaint.

Read here: DEKRA report

Viersen. The black tire fragments that are often left behind on German highways – often from commercial vehicles – are often the result of mechanical tire damage, but very often also of insufficient internal pressure in connection with an overload of the commercial vehicle tires. Apart from the fact that such damage is annoying and expensive for the owner, the destruction of the tire while driving also leads to a significant impairment of road safety.

In the course of a comprehensive series of inspections carried out by DEKRA experts, it was found that more than half of the commercial vehicles inspected had one or more faults in the area of the tire valves. In particular, on axles with twin tires, the valves of the inner wheel were not accessible or only accessible with considerable effort. Checking and adjusting the tire pressure was difficult or even impossible. In many cases, checking and adjusting the tire pressure would have required disassembling the dual wheels or at least removing the tightly screwed-on wheel caps. In more than half of the truck wheels examined (1012 vehicles examined), any valve extensions that may have existed and would have allowed tire pressure checks and tire inflation were either not present, badly worn, already broken, or otherwise non-functional. Insufficient tire inflation pressure in commercial vehicles and buses can, at best, lead to increased tire wear and fuel consumption. At worst, it can completely overload the tire structure and, in some cases, have serious consequences. 

“In view of the economic consequences and the potential risk, the use of suitable valve extensions with a safety mechanism is strongly recommended,” says Dipl.-Ing. C. Döbber, accident expert at the DEKRA branch in Mönchengladbach.

Contact:

DEKRA Automobil GmbH

Mönchengladbach branch,

Dipl.-Ing. (FH) C. Döbber, branch manager

Jakobshöhe 10, 41066 Mönchengladbach

Tel. 02161-60755, fax 02161-605859 

E-Mail: claus.doebber@dekra.com

29.06.2005

Viersen. Who hasn't seen them, the black fragments of tire – often left behind by commercial vehicles – on German highways. Tread damage caused by foreign objects, overloading and, in many cases, insufficient air pressure in commercial vehicle tires can lead to such damage. This damage is not only annoying and expensive for the commercial vehicle owner, but also dangerous for the commercial vehicle itself and for other road traffic. 

Insufficient air pressure in the tires of both commercial vehicles and passenger cars leads to excessive heating and stress on the tire structure, which not only means increased fuel consumption and tire wear but also carries the risk of massive tire damage. The experts at DEKRA in Mönchengladbach came to a surprising conclusion during a series of examinations on more than 1,000 commercial vehicles (including more than 100 buses). More than half of the commercial vehicles examined (including 87 buses) had at least one, and in many cases multiple, defects in the tire valves.

In particular, on axles with twin tires, the tire valves of the inner wheel were either not accessible or only accessible with considerable effort. Checking the tire pressure or even inflating the tires with simple on-board tools was difficult or not possible at all. In many cases, checking and adjusting the tire pressure would have required the twin wheels to be dismantled or the bolted wheel rims or wheel trims to be laboriously removed. 

Valve extensions, which would have enabled tire pressure monitoring and tire inflation, were either not present, badly frayed or already broken on more than 650 truck wheels and more than 135 bus wheels. Many of the valve extensions found were loosely screwed on without any means of fastening and were brittle or porous.

In commercial vehicles and buses, severely reduced tire inflation pressures can, at best, lead to increased tire wear and fuel consumption. At worst, however, they can completely overload the tire structure, resulting in serious consequences in individual cases.

“In view of the economic consequences on the one hand and the potential danger on the other, the use of suitable, properly attached valve extensions with a safety mechanism is strongly recommended to ensure quick and efficient control and correction of the tire pressure on commercial vehicle wheels,” says Dipl.-Ing. C. Döbber, accident expert at the DEKRA branch in Mönchengladbach.

Contact: 

DEKRA Automobil GmbH

Mönchengladbach branch, 

Dipl.-Ing. (FH) C. Döbber, branch manager

Jakobshöhe 10, 41066 Mönchengladbach

Tel. 02161-60755, fax 02161-605859 

E-Mail: claus.doebber@dekra.com

29.06.2005

Radio news: “... Caution! Motorway A... Tyre parts on the road...” Who has not heard this frightening message? According to the managing director of Glauch Produkt GmbH, Tobias Glauch, these messages could be heard less often in the future if the proper condition of all tyre valves had to be confirmed during the annual general inspection (HU) and the 3-month safety inspection (SP).

Glauch Produkt GmbH, in collaboration with DEKRA Mönchengladbach, is conducting a study on the completeness and unimpeded accessibility of tire valves and tire valve extensions on at least 1,000 commercial vehicles. The aim is to prove the claim that around 50% of tire valves and tire valve extensions are not accessible, defective and sometimes not even present. Simple plastic valve extensions, which are used almost 100 percent of the time in original equipment from manufacturers for cost reasons, are often not present or have broken off due to their “brittleness”. When the air pressure gauge is attached, the plastic tubes break off even when it is cold, according to Glauch. The extreme and changing thermal stress near the brakes and in the cold outdoors is so enormous that the material quickly becomes brittle and breaks. Foreign objects such as stones, mud, snow and ice, which cannot be avoided, can easily cause this weak component to break, he continues.

This serious defect makes it difficult to check the air pressure, as it is only possible to do so by dismantling vehicle components or removing the outer dual tires. Glauch asks who would want to go to all that trouble. Most drivers are unable to carry out this “additional and specialized work” during a trip or journey. Presumably, the most convenient route is taken first and the destination is driven to. There, the tire air pressure is checked, or it is checked. However, according to the law, the driver is obliged to ensure the correct air pressure before starting the journey. In Glauch's opinion, the air pressure should even be checked and corrected during all safety tests or main inspections. In most cases, it would only be checked before the holiday trip. 

He refers to the statement of the Federal Statistical Office that one in four accidents involving personal injury, caused by technical defects, can be traced back to tire damage. Glauch believes that this enormous number could be significantly reduced if there were an inspection requirement. (Source: Federal Statistical Office of Germany). Even with the new pressure monitoring systems, this problem would not be prevented, since air must ultimately be “refueled”!

Glauch himself is also the managing director of his travel company of the same name, Glauch Reisen GmbH, and operates 25 buses in travel, scheduled and school transport. He says that drivers would even set off if one tire looks “a little flatter” than the others. And that would certainly not only be the case in his company: “In our stressful times, everyone is looking to get ahead.” 

In the wake of the tragic bus accidents, the ADAC has already made the correct demand to bus manufacturers to make the tire valves accessible from the outside – even if wheel caps are present. By implementing this requirement, the air pressure can be checked quickly without having to remove and replace 4 or 6 wheel caps. In most cases, drivers are unable to do this because the technology is too complicated and, in some cases, special keys are required that are not in the vehicle. So the vehicle is driven – and that's with people on board or with a total weight of 40 tons, without any obligation for a specialist to check it, only at the responsibility of the driver.

KRAVAG insurance is also supporting Glauch in his efforts and is closely monitoring the investigation. Other insurers would certainly take notice if the test is positive, because then a lot of damage and large payments can be avoided.