RIDE TESTS
Page 29
If you've noticed an error in this article please click here to report it so we can fix it.
Once again, we took advantage of MIRA's unique ride meter to test the ride quality of each truck over Iwo surfaces.
The meter is connected to sensor pads which measure the movement over a preselected range of frequencies in the cab floor, seat cushion and backrest. The chosen frequencies are those to which humans are sensitive while the rest are filtered out. In all cases, the lower the figure, the better the ride. We've grouped the 6x2s together and were expecting them to achieve better results than the 4x2s but, as the chart shows, this did not necessarily follow. The Foden recorded the worst results on both the broken surface and the smooth road. Our seat-of-the-pants feeling was also that too many bumps came through. On the smooth surface the sensors detected more than twice the movement recorded by the best cabs each time. None of the others was quite as clear cut but the Mercedes Actros' comparatively poor result came as a surprise. Much of the vibration recorded, particularly by the floor sensor, was transmitted from the engine. The vehicle was rushed to us from the factory and Mercedes reckons that the cab suspension air bags were over-inflated. The results were consistent with such a problem—vertical movements recorded were comparatively worse on the smooth surface while backrest movement was high on both surfaces.
The magic carpet award is shared by MAN and Scania, again bearing out our seat-of-thepants feeling that these two were generally a cut above the rest.
The MAN's backrest movement on the smooth surface suggests a gentle low-frequency cab nod. It's a pity they didn't share the same axle configuration which would have given a more direct comparison between the two. Among the new cabs this year the Scania clearly wins but the Daf also performed well, particularly for a mechanically suspended cab. Given our results, Daf's suspension expertise could be put to good use by its Sandbach step-sister.