Read a thread a few days back about adding 1" spacers.

xkracer responded that this would cause "tramline like a biatch".

I definitely know what "biatch" means; but, what the heck does "tramline" mean?

xkracer, Were the spacers that you used on a 20" wheel installed on a car that was also lowered?

Would this tramlining happen with a custom made 20" wheel that didn't use spacers but extended the wheel lip out about an inch?

Once you get into the $1500-$2,000 per wheel range, you can pretty much design whatever you want nowadays.

Does this qualify as a goofy question that I should have figured out in my head?

 

Tramlining is when the car tries to steer itself in the grooves in the road. You'll feel the steering wheel pull from side to side and you're constantly having to correct for it. Many years ago, back in the days of bias ply tires, I had a bias ply spare, but the other tires were radials. I had to put the spare on one of the front wheels, and the steering got very very "squirrely". That's because when you mix a bias ply tire with a radial you get tramlining.

 

The lowering of the car would effect it some but not as much, the issue is also you are moving the offset far out of its limits.

What you are saying is, by extending the J size by 1" will it still cause tamlining but the offset will still be correct ?.... Simple answer, yes but not as bad.

I have 13J on the rear (335 tires) on my XJS and 9.5J on the front (255 tires), yes it tramlines but no where near as bad as that XKR did when I drove it

 

I have 1'' spacers on my 18'' double fives and the xkr does not tramline.

I remember back on my 02 ls1 camaro when I went with 18'' (+2'' size) low profiles it did tramline, I think it was a 35 profile tire. So in my experience low profile tires is when you hit those issues.

 

I must admit that, given the 'huge' distance between the wheels across the axle, and the width of the tyres, I can't really understand why tramlining would suddenly appear when you add an extra 20-30mm to the track.

 

Its all to do with geometry, tyre pattern also, I always found Pirelli's tramline more than Sport Maxx

I agree that 1" spacers work well with 18" wheels, I beleive I also said this in the thread ed mentioned

 

OK, I believe you I've just got this thing about phaaaat cars and would really have liked to put spacers on.

 

I think it has more to do with the position of the wheels in relation to the pivot point than the overall track. The spacers move the wheels outward but the pivot stays in the same place. That means that the torque arm is longer, so the road effectively has more leverage to turn the wheels away from a straight line. If it was possible to move the entire suspension assembly outward by 30 millimeters, then there would be no tramlining at all.

 

Ah right, I think we have been talking at cross purposes. Tramlining with spacers on the front axle, I can understand. I was actually talking (or rather, thinking to myself...) about the rear axle. My bad

 

What the Rev says is bang on, I just summed it up very simplistic as 'geometry' but the same applies at the back to a certain degree, you do actually feel the back of the car being dragged over almost causing rear end skip

 

The old XJR/6s (like mine) are notorious for tramlining....sometimes to the point of being outright scary.

Having done battle with this issue I remain convinced the the tires themselves (profile, casing construction, tread design,etc) are the single most important factor. Other issues (suspension wear, alignment, wheel bearing adjustment, etc) play in to worsen the situation.


Cheers
DD