I put on Falkn Azenis PT722 on mine in Nov. 235/50/r17 on my xjr and completely wiped out my tram-lining problems. and the treadwere on these things is excellent. i think they where marked at 680. idk but i love them.

 

I'm also interested to hear if anyone has tried more toe-in or what degree they are currently running.

When I purchased my XJ6 Sport it has very worn 225/55 R16 Dunlop SP6000 which had a very agressive tread pattern. The tramlining was a nightmare, wasn't game to let my wife drive the car. I immediately changed to 225/60 Kelly Unltra GTs and the tramlining was 95% eliminated.

Despite this improvement the car still has a slight tendancy to follow ruts in the road (which my XJS on 15 inch wheels doesn't do). All the suspension bushings and wheel bearings appear to be in good shape.

The car is running 1.1mm of toe-in on each front wheel according to the check when the tyres were fitted. I've now done 20,000km on the new tyres with no uneven wear. I often wonder if a little more toe-in would improve the straight line stability further. Obviously I don't want to go to far and induce tyre wear.

Any ideas on how far can I go? I would imagine this is also of interest to XJR owners

 

According to sciencemadesimple.com:

"1.1 millimeters is equal to 0.04 inches"

As 1/8 inch is 0.125 inch, it would be about 1/24 inch. That is almost non-existent. But, I do not own a X300. The X308 does not seem to have a tramlining problem and it has a greater toe-in spec.

One other thought ... perhaps steering rack movement contributes to the problem.

By this I mean that my understanding of "tramlining" is that the vehicle does not respond to minor steering corrections when encountering tramlines or ruts running generally in the direction of travel. In those circumstances, I anticipate some disturbance in the steering, but so long as the steering responds to my input, I am not bothered .. I would be bothered if my inputs had no effect on correcting the disturbance. A steering rack on soft bushings would contribute to less precise corrections.

 

Entirely plausible






In the worse cases X300 tramlining (XJR/6 especially) feels like your passenger has grabbed the steering wheel, given it a good yank, and then refuses to let you have it back !.

Or, envision two sets of railroads track, parallel. You're riding along one railroad track, minding your own business, and the car jumps over to the *other* railroad track and refuses to come back :-)

This is why I never let my kids drive the Jag at highway speed. I was afraid they might panic. It can be very startling to the uninitiated.



And that's the rub. In the worst cases it won't respond.....not without a fight, at least.



Worth checking, for sure.

Cheers
DD

 

I am with you Doug they where dangerous with the big tyres on them
I just took my car for its first run since October last year on the weekend didn't last long traffic made me turn round and head for home
I might drive it to Melbourne next month been looking forward to a long trip hasn't done one like that since the day I bought it in Sydney in 2007 and drove it home to Queensland 900 k,s very glad its got 235/50/17 tyres on it

 

In that case, it may be the very minimal toe-in becoming toe-out due to suspension compliance, steering rack movement, or the steering hydraulics not being able to resist backlash/kickback.

All completely WAG's since I don't have any skin in the game.

Has Brutal ever had anything to say about this since he owns the same thing?

 

I don't recall if Brutal ever chimed in on the subject.

There are so many variables at play. Tires, though, are the biggest contributor. It's reasonable to conclude that different tread, shoulder, and casing/sidewall designs would behave differently. In my case just going to a different tire (but original size) reduced the problem greatly.

Later I went to a smaller size and the tramlining disappeared entirely.

Anyhow, for those still suffering, tweaking the toe-in is worth a try. I also found that nipping the wheel bearings right down to zero makes a difference.

Cheers
DD

 

an article on tramlining from tirerack:

Tire Tech Information - Tramlining: Coping with the Ruts in the Road


On another note, I ran into the concept of camber change due to the inter-relationship of caster and steering axis inclination. The short synopsis is that a tire with zero or negative camber might end up in positive territory with the right combination of the two.

 

AutoSpeed - From the Editor

 

Hi guys, this is a very informative thread as im about to buy 4 new tires for my 97 XJR/6..i just had it for 3 weeks now and its currently on 245 40 17(looks really terrible). i like the look of the stock 255 45 17 but they are not available here in my country....what do you think of 245 45 17's? Im Considering also 235 50's. both are available locally

 

I replaced the stock size with the 235 50s and they still look very substantial and I really could not notice any difference in appearance and they helped a great deal with a tramlining problem I was having

 

Have a look at this site Visual Tyre Size Calculator | Kouki Tech

Will help you calculate what tyres you can use

My XJR6 like I said had the 255/45/17's on it never again

The 235/50/17's sit better on the XJR6 wheels also nicer ride and no tram-lining and less gutter rashing

245/40/17 would make your speedometer out something shocking

The 235/50/17's actually got the speedometer more accurate

I think if they made 245/50/17's you could get the speedometer totally accurate

I have used the above tyre size calculator on all my cars don't listen to what the tyre guys say unless they are an older guy that has been in the business for a long time

 

My X300 is on 18" Asteroids, with Toyo 245/45 x 18 tyres. they are the same diameter as toyo 225/60 x 16s which I also have on chrome Turbines (original wheels)

I tries 235/50 x 18 on the Asteroids first, but they rub inside the front wheel arch at half-lock - just 7 mm more on the radius, but enough to cause trouble.

My sppedo overreads anyway. It reads 60 km/h when driving up to a roadside speed readout of 53.
I got a ticket at 114 k's, reading 120

 

Was that 114 k,s in a 110 zone or 100 zone
If it was a 110 zone I would take it to court 4 k,s over that's laughable

 

hi doc,bought 4 new tires today,the 235 50's would have been perfect but only 3 pcs on stock! so i had no choice but to get the 245 45's...they looked great too!!! got the nitto motivo. the kouki tire size calculator is really cool. thanks for your help doc!

 

If I can chime in, it was my understanding that "tramlining" is not necessarily following ruts, but more like behaving that way whether there are ruts/rails/etc. present or not.

It's also my understanding that this condition can be alleviated by aligning the car while under load; i.e., tying or weighing it down with sufficient force to emulate driving conditions.

I just had my struts/shocks renewed and needed a 4 wheel alignment, naturally. Unfortunately the alignment shop doesn't seem to understand the need to tie the car down and so my "fresh" XJ6 has a BIT of a "tramlining" problem altho nothing too disconcerting. Still, it IS annoying.

 

Possibly...but not sure if I quite agree.

It's just that, in some cases, even the *slightest" irregularity will bring on the problem.

If the road surface is very smooth and flat but the car won't stay on course I'd suspect an alignment issue and not a tramlining issue





In some cases that mght reduce or eliminate the problem but there are SO many variables..tires being the most prominent....that there doesn't seem to be a single cure that works in all cases




If you have and read the X300 service manual you'll see that there is indeed a height specification for wheel alignments on the standard model. However, as if to say something and then take it away in the same breath, the text goes on to say that different models have slightly different ride heights and the alignment should be done at existing ride height!

That's Jaguar for ya

Cheers
DD

 

Really excited to find this thread, as this tramlining is something that I am experiencing badly with my 97 XJR with the stock tire size.

I have it scheduled for an alignment and I'll mention to the tech that maybe a smidge more toe in is suggested, so we'll see.

But I'll need tires in a year or less, so this is great news that a slightly narrower tire may solve much of the problem.

The Continental PureContact with Ecoplus sounds like it might be a great fit (literal and application). The performance and treadlife look like a win/win:


http://www.tirerack.com/tires/tires....EC&tab=Reviews


.

 

I recently switched to 235/50/17 less than two months ago and 99% of the tramlining is gone. There was one spot on a road near where I live that has very deep ruts from heavy trucks and hot pavement and if I didn't keep on top of it I would find myself in the other lane. Now it don't even notice it, zero issues. My only complaint is the handling, it doesn't feel like it is "sticking" the curves as gracefully as the wider 255 tires. For my current typical driving style however I prefer the narrow tires. My thinking is I want to replace my current "wheels" with a different style as I think this style is horrendous and when I do put 255 on them as my "performance" set.

 

Something else interesting...

The X300 XJR OEM rim is a 17x8" rim. Some quick "Googling" of various tire manufactures shows the stock tire size of 255/45-17 to often be just a bit too wide for an 8" wide rim. This size seems targeted at an 8.5" and above rim. While 1/2" may not sound like much, it definitely can impact how a tire fits the rim and therefore its shape and contact patch, etc.

However, a 235 or 245 like we've been discussing is right in the sweet spot for a 17x8" rim.

So it may be that although Jaguar spec'd the 255 tires from the factory, in fact for the OEM 17x8" rims a narrower tire is actually a better fit, not just anecdotally from owner observations, but also technically?

So maybe we aren't "crazy"

For example:

http://www.yokohamatire.com/tires_10...m_wheel_width/


.