| Author | Message | ||
     Benoit Leus Frequent User Username: benoitleus Post Number: 400 Registered: 06-2009 |
Recently, I hit a deep pothole on a local road while driving at 100km/h with my Mercedes E300 Coupé (W238). It became clear not all was we'll as the car developped a vibration through the steering wheel as well as the seat. After inspection by my garage both RH rims appeared to be bent. They were replaced with brand new ones, which solved most of the vibration but not all of it. They didn't replace the runflat tyres as they showed no bulges and had plenty of thread left on them. Also the tracking hasn't been realigned. Could it be that the tyre structure has been damaged, causing the vibration ? Benoit | ||
| David Gore Moderator Username: david_gore Post Number: 3424 Registered: 04-2003 |
Hi Benoit, Delamination of the tread from the underlying belt of the tyre will cause vibration and a pulsating sound as the bulge in the tread passes across the road surface with each revolution of the wheel. | ||
| Larry Kavanagh Frequent User Username: shadow_11 Post Number: 480 Registered: 05-2016 |
Hi Benoit, Could well be that the tyre/s are damaged. If you swap the front wheels with the rear - one at a time - it may alter the source of the vibration and then you will know. | ||
| Vladimir Ivanovich Kirillov Prolific User Username: soviet Post Number: 1532 Registered: 02-2013 |
My guess is both tyres are suspect. I would replace them. Your wheels can possibly repaired. Here the process is called "rolling". I have zero idea about how this is done but about 16 years ago in Sydney I had a BMW 745i and which have pretty but very soft alloy wheels all 4 of which were bent from nice Sydney potholes. I got all four rolled and problem was solved - no vibration right up to 120 mph. | ||
| David Gore Moderator Username: david_gore Post Number: 3426 Registered: 04-2003 |
Vladimir, I know this technique works on steel rims from past experience on "goat track" country unsealed roads. This is a consequence of the ductility of steel which has the disadvantage that the rim can both deform when subject to sudden impact and the advantage of being easily repaired by rolling on a wheel lathe afterwards. It is my understanding most alloy wheels do not have the same ductility and specialised techniques apply if the deformation/damage is capable of being rectified. Using "soft" wheels as occurred in your case will always be a problem on our roads as you discovered. | ||
| Vladimir Ivanovich Kirillov Prolific User Username: soviet Post Number: 1540 Registered: 02-2013 |
David as I said I don't know the process used but from memory it was $50 a wheel to be rolled and it worked because I often trashed the Beemer over 100 mpg and it was German smooth as. Now question: Are the original mag wheels on my Purple Spirit soft like the BMW or stronger like a steel wheel? At the moment that Spirit is bloody marvellous on the road so no problem with it and it does look as though the swine government is going to bitumen my gravel road all the way to my town which means I can forget about applying sheeting to the underneath of the car. Naturally if the bitumen does go down I will be able to cruise down to Airline Beach from my country lair looking like King Billy in my Amani and Florsheims for nefarious purposes and truly cut sick. | ||
| Mike Thompson Frequent User Username: vroomrr Post Number: 851 Registered: 04-2019 |
We call bitumen, asphalt or tar, had to look it up never heard it called that before. On a hot day it might provide more under coating for your car and retread your tires (as well as the sides of your car).  In the USA midwest we have a lot of limestone rock due to it being a shallow ocean for millions of years to make roads with. And its quarry has made miles of tunnels under the earth which now are being converted to warehouses and businesses in the caves. | ||
| David Gore Moderator Username: david_gore Post Number: 3432 Registered: 04-2003 |
Vladimir, I do not know the answer to your question as I have no idea of what alloys are being used and whether the wheels have been cast, forged or machined from a forged bloom. Almost half a century has passed since I had contact with what was the very early days of alloy wheel development. | ||
| Vladimir Ivanovich Kirillov Prolific User Username: soviet Post Number: 1548 Registered: 02-2013 |
David its the first RR mags to appear. Perhaps my memory is fading but the later Spirits used a far prettier mag that looked like it was chromed. Mine are the silver ones with a cap over the nuts. Well anyway they cannot be bent as the car drives velvet smooth. I am guessing they are not soft stuff like BMW mags. Mike I was always jealous of US highways which are concrete. Here the highways are all bitumen and on a very hot day it can indeed melt. There are some really nasty photos on the net showing the mess especially on trucks. Except for over certain bridges that have concrete in Australia bitumen is as good as it gets. | ||
| David Gore Moderator Username: david_gore Post Number: 3435 Registered: 04-2003 |
Vladimir, Most of the new NSW toll roads are concrete as they have to withstand the effects of the ever-increasing numbers of B-Double semi-trailers as a consequence of the decline of the NSW rail freight service. | ||
| Benoit Leus Frequent User Username: benoitleus Post Number: 401 Registered: 06-2009 |
Thank you everyone for the advice. I went to my local tyre fitter who aligned the tracking and rebalanced the wheels as the garage had done a poor job with 2 wheels well out of tolerance. The car drives much better now altough there is still a hint of vibration. They suspect internal damage to the tyres, just as David said. I can't change the wheels front to back as Larry suggested as they are a different size. Finally, the rims themselves have been replaced by new ones, so "rolling" them will not be necessary. Benoit |
