MONTREAL, Que. – Some Quebec carriers are finding that the tires on the self-steering lift axle in quad configurations are taking brutal beatings in tight turns, throwing out wheel alignments and jacking up the cost of running quads. Fortunately, tire manufacturer Michelin thinks it has a solution.
Quads with a self-steering lift axle, which are part of the Quebec-Ontario weights and dimensions harmonization deal, were supposed to be the ticket to allowing carriers to run with more weight – as much as 34,000 kilograms.
The trade-off though, was that drivers would no longer be allowed to lift the axle from inside the cab, thus ensuring no sneaking around on just three axles.
The self-steering foremost axle, which can pivot 20 degrees to the left or right in turns, was supposed to compensate for not lifting the axle.
The rub, too literally, is that carriers are finding that in tight turns, the wide base singles that trailer manufacturers fitted on the lift axles are getting ripped up and have to be scrapped prematurely.
The giant carrier Groupe Robert got its first quads with the steerable axle in December 2001, and is currently running about 30 53-foot trailers under special permits. “Rapidly, in the first months, we saw problems with bad wear on the shoulder. The next May and June we had to replace many of the tires. The excellent tread (i.e. excellent grip) threw the wheels out of alignment. The tires don’t do half what we were getting with the traditional lift tires we used to have,” explains tire manager Francois Gareau, who freely acknowledges: “The X-One for long haul is beautiful (but) wasn’t planned for the lift axle.”
The quad self-steering lift axle is designed to take the Michelin’s X-One XDA, even though Michelin specifically designed this wide base beauty as a fuel, weight and maintenance-saving replacement for duals in long haul drive tire applications.
Somehow though, it got worked into the lift axle configuration with no regard for the fact that it was simply never designed for such duty.
Trailer manufacturer Manac says it is merely using the tire specified by its clients.
Groupe Robert acknowledges that it picked the X-One XDA, but that there was no alternative that would work.
Michelin says no one consulted them until too late, although it is sure taking the heat from riled-up customers.
“…It is not an appropriate tire for the application,” says Ralph Beaveridge, Michelin’s marketing director for truck tires.
“It is unfortunate that … development took place and we were never approached by the trailer manufacturers for our help in developing the application.”
Once Michelin understood the problem it quickly began testing an alternative wide base tire – its XTE2, common on European trucks.
Compared to the X-One XDA, which has a load rating of 5,000 kilograms, a 380mm tread width, a 727 square-centimetre contact area and a very square profile, the XTE2 has a 4,500-kilogram load rating, a 310-millimetres tread width, a 606 square-centimetre contact area and a more rounded profile.
“By all rights the XTE2 should do exceptionally well in this configuration,” says Beaveridge.
The model XTE2 is now approved internally by Michelin and is DoT approved, but, says Beaveridge, “We are going to be testing it from here to the end of December to see if it performs to the standards our customers expect.
“We are not ready to commercialize that tire until we are satisfied with our tests.”
Groupe Robert has begun testing the XTE2 on two of its 53-foot quads, as is a Quebec trailer manufacturer.
Transports Quebec is apparently dealing with the issue head-on – which is a good and brave thing. After all, notes Beaveridge, “Major fleets in Quebec are saying ‘You imposed this steerable quad configuration on us and we don’t think it is a feasible issue.'”
It is strange though that this problem was discovered so long after the horse fled the barn and the doors were nailed shut.
To make a comparison with how the aviation industry conducts its affairs, thousands of hours of obsessive flight-testing precedes the mandating of new aircraft equipment. It is never the other way around.
Be that as it may, Gervais Corbin, who is responsible for Transports Quebec’s weights and dimensions dossier, says: “We formed a working group with three transporters, a trailer manufacturer and Michelin to establish the problem. We will do a technical evaluation of the steerable axle. We have a responsibility to help find out a solution to this problem; e.g., do we increase the maximum steer axle, use a different tire?”
Transports Quebec is striking for results later this fall, but what would carriers really like for Christmas?
“Our main request to Transports Quebec is to bring the switch for the lift axle back into the cab,” says Gareau.
However, he adds: “Ontario won’t accept that.”
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