Some of you may remember that I posted a few months back about my woes with tramlining and instability in the straight ahead position on my e85. The car was new to me and I changed the rears pretty soon after I bought the car since they were close to the wear limit. Almost immediately I noticed that the car was tramlining badly and actually quite unpleasant to drive with very twitchy steering in the straight-ahead position. I wanted to believe it was the tyre change, but the car was new to me and a number of people doubted that rear tyres could do this - which I found easy to believe since I had pretty much the same intuitive feeling.
So, I had the steering geometry checked and tweaked (it was very slightly out), fiddled endlessly with tyre pressures (harder tyres seemed to make it better), worried incessantly about power steering problems (esp the angle sensor), considered playing around with new FRONT tyres and generally doubted whether buying the car at all was a good idea.
Then last week I decided to hang the expense and put another set of rear tyres on. So, off went the Nexen N8000s and on went some Falken 453s to match the 452s on the front. The impact was immediate - the tramlining was immediately almost completely suppressed and the stability was much, much improved. I can't say that the car is as stable as my main car (a 335i touring), but I'm no longer thinking that I'm about to be yanked off to the side of the road and can actually relax a little while driving it now.
I'm yet to play with pressures again and TBH, the fronts will need changing within a few thousand miles, but I'm now feeling much happier with the car.
The question in my head is why the rear tyres affected the car's handling so badly. I'm assuming it's something to do with the flexibility of the side walls. Certainly the Falkens produce a much harder ride. My theory is that minor tramlining from the steering was being amplified by flex on the rears causing a sort of oscillation.
In any case, what I can say is that the Nexen N8000s are best avoided on the e85!
So, I had the steering geometry checked and tweaked (it was very slightly out), fiddled endlessly with tyre pressures (harder tyres seemed to make it better), worried incessantly about power steering problems (esp the angle sensor), considered playing around with new FRONT tyres and generally doubted whether buying the car at all was a good idea.
Then last week I decided to hang the expense and put another set of rear tyres on. So, off went the Nexen N8000s and on went some Falken 453s to match the 452s on the front. The impact was immediate - the tramlining was immediately almost completely suppressed and the stability was much, much improved. I can't say that the car is as stable as my main car (a 335i touring), but I'm no longer thinking that I'm about to be yanked off to the side of the road and can actually relax a little while driving it now.
I'm yet to play with pressures again and TBH, the fronts will need changing within a few thousand miles, but I'm now feeling much happier with the car.
The question in my head is why the rear tyres affected the car's handling so badly. I'm assuming it's something to do with the flexibility of the side walls. Certainly the Falkens produce a much harder ride. My theory is that minor tramlining from the steering was being amplified by flex on the rears causing a sort of oscillation.
In any case, what I can say is that the Nexen N8000s are best avoided on the e85!
Loughborough