What a strange vibration!

Some weeks ago a colleague of mine and I went to a Hydroelectric power plant to perform some electrical tests on a High Voltage transformer. This power plant is on the Appennino (a mountain  chain that goes from north to south in the middle of Italy) between Genova and Piacenza, and the street to get there is very narrow and full of curves.

In addition, some days before our trip there was a huge rain storm during which the amount of water that usually falls in four months fell in two or three hours. The storm did a lot of damage to the street that was broken or covered with mud in many places, and also to the power plant that was flooded (that why we went to perform the tests).
We arrived there with our new company car and on the outward trip we didn't have any problem. During the return trip, when the street became a little more straight and we were able to speed up a bit, the car started to vibrate. The vibration seemed to be generated by the rear wheels, and it increased with speed. So we stopped the car and we checked the tyres looking for something strange. We didn't find anything on the outer diameter of the tyres, but instead we found a big amount of solid mud stuck in some points of the rim (especially on the right wheels). We removed the mud and the vibration disappeared. It's unbelievable that some mud can change the balance of a car tyre! I really couldn't believe that it would be possible.

Hello Andrea,

I have never heard of this but if you think when you change a tyre, the fitter usually balances the tyre by adding small lead weights to the rim - this is to stop this type of vibration.

Just some small errors and one part that I needed to rearrange to make it better. Be careful - 'damage' is an uncountable noun in this context so you can not have several of them.

Hope this helps

Bob