Info needed please

[Lazy-Ferret]

With regards to the bearings, I have often wondered about this. I understand how spacers will "up" the bearing wear, but not how wider wheels, with the correct offset should do this.

I can see that if you take the standard wheel, and just move it out on spacers by 2", that you are putting a twisting torque on the bearings, making a lever that is pushing up on the front bearing, and down on the rear one. This has to be bad.

Surely though, if you just fit wider tyres, and you keep the same amount of tyre on the inside of the bearing, then there should not really be that much extra load on the bearings.

My thinking is, very simplified, if the wheel is 8" wide, and the bearing is 2" over all, then with a wheel with no offset, you have 2" on the inside of the bearing, 2" under the bearing, and 4" on the outside. If you up the wheels to 10", and put in a 2" offset, then you still have 2 inches on the inside of the bearing, 2" under the bearing, and now have 6" on the outside. Why would that put any more wear on the bearing?

Originally Posted by AlexD333

Tyres are not too big, elty is running 33's make it fit is running 35's

as mentioned its the offset of the wheels rubbing when on articulation

EDIT - im running 32's

What I do not understand in Alex's case, is how his wheel size got larger

What is the actual size of the tyres, I know mine are 265/70 x 16, which means the width of the tyre is 265mm give or take a small amount. the 70% profile means that overall the hight of the wall with respect to the width of the tyre is 70% of 265mm, so the wall is 186mm high, so with my tyres, I end up with around 777mm overall wheel diameter, which is 30.5", and I get no rubbing. So basically, using standard number rounding, I could say I am running on 31's, which is the standard size for my car.

I know a lot of people, when they want to increase the diameter, just fit a bigger width tyre, which by default, makes the tyre diameter larger, when really, you should only be adjusting the profile, so instead of 70%, you should go for 80%, which would give 830mm (32.5") overall wheel, but the width would remain the same, and therefore, in theory, not cause fouling.

So in Alex's case, is the tyre rubbing because the width is greater now he has fitted bigger tyres, or is it because he has increased the articulation, and now the wheel is just getting to places it was never designed to get to. From the pictures, it looks like the tyres are rubbing regardless, so it must be a width issue, and while spacers would solve this, the best way for the long term survivability of the cars mechanics is to either move the tyres onto different wheels with a different offset, moving the tyre away from the body, and hoping it does not then hit the outside of the wheel arch, or better still, spend lots and lots of dish, and get new tyres that are thinner, with a much larger profile.