Community Forums

Mentor · 01-28-2015, 06:18 PM

Just a thought, I have a 98 Southwind on the P30 chassis with the front wheels sitting well inside the wheel wells with that narrow stance. They are of course the same rim and tire as the rear duals and I am wondering if anyone has tried to reverse them, mount them as the outer duals are mounted. This would give a wider stance hence more stability but there are questions. What are the effects of reversing the bearing loading? It won't increase the load but will reverse the load direction. How much will the extra leverage compress the front coil springs? It should not change the actual steering geometry as the spindle et al remains as is. Body clearance aside does anyone have any experience or thoughts on this.

slowmachine · 01-28-2015, 06:33 PM

This is a mechanical disaster in the works. Absurdly dangerous to you and everyone else on the road.

Mentor · 01-28-2015, 06:40 PM

Quote:

Originally Posted by slowmachine

This is a mechanical disaster in the works. Absurdly dangerous to you and everyone else on the road.

What technical details do you base this on?
In the past I had a Ford F350 with an 11.5 foot Bigfoot winterized camper, huge reverse chromes and off road mudders with zero trouble over the years. They stuck out so far I had to flair the fenders.

TXiceman · 01-28-2015, 06:42 PM

The wheel bearings are designed fo the load based on the wheel offset as mounted. reversing the wheel will over load the bearings and lead to a bearing failure.

Ken

PushedAround · 01-28-2015, 06:43 PM

I have a good bit of suspension engineering under my belt, and you cannot do what you are thinking. Your suspension was designed with the wheel offsets as they are. There are many factors in play here including caster angle, scrub radius, bump steer and bearing loading. Changing wheel offsets by as little as an inch can start making things squirrelly, changing them by the foot or so that would occur by reversing the wheels will produce horrific steering and handling.

You did not say if your front end has a solid axle, but if it does and you really want to increase your front track, a quality truck suspension shop could install a longer axle, with all of the appropriate longer linkages to properly produce what you are looking for.

Mr_D · 01-28-2015, 06:47 PM

Quote:

Originally Posted by PushedAround

I have a good bit of suspension engineering under my belt, and you cannot do what you are thinking. Your suspension was designed with the wheel offsets as they are. There are many factors in play here including caster angle, scrub radius, bump steer and bearing loading. Changing wheel offsets by as little as an inch can start making things squirrelly, changing them by the foot or so that would occur by reversing the wheels will produce horrific steering and handling.

You did not say if your front end has a solid axle, but if it does and you really want to increase your front track, a proper suspension shop could install a longer axle, with all of the appropriate longer linkages to properly produce what you are looking for.

Might be cheaper and safer to get a new rig!

Mentor · 01-28-2015, 06:48 PM

Quote:

Originally Posted by PushedAround

I have a good bit of suspension engineering under my belt, and you cannot do what you are thinking. Your suspension was designed with the wheel offsets as they are. There are many factors in play here including caster angle, scrub radius and bearing loading. Changing wheel offsets by as little as an inch can start making things squirrelly, changing them by the foot or so that would occur by reversing the wheels will produce horrific results.

You did not say if your front end has a solid axle, but if it does and you really want to increase your front track, a proper suspension shop could install a longer axle, with all of the appropriate longer linkages to properly produce what you are looking for.

I have independent front coils. The main reason I wonder is the fact I had a Ford F350 with an 11.5 foot Bigfoot camper with huge chrome reverse wheels with no problem at all. they gave about a foot wider stance which also seriously changed the bearing loading as the leverage was increased. On a P30 it would not increase the loading but would reverse it and at the same time increase the apparent load to the coil springs due to the increased leverage on the assembly but no further leverage on the bearings.

PushedAround · 01-28-2015, 07:09 PM

Quote:

Originally Posted by Mentor

I have independent front coils. The main reason I wonder is the fact I had a Ford F350 with an 11.5 foot Bigfoot camper with huge chrome reverse wheels with no problem at all. they gave about a foot wider stance which also seriously changed the bearing loading as the leverage was increased. On a P30 it would not increase the loading but would reverse it and at the same time increase the apparent load to the coil springs due to the increased leverage on the assembly but no further leverage on the bearings.

Without knowing the offsets on those chrome reverse wheels, they may not be as great as you think. What I mean is that the extra width could have been split between inside and outside, and though they are deeper on the outside, some of that width is still towards the inside and so your offsets may not have changed as much as you are thinking. Your front end may still have been operating with-in acceptable limits and so there was little deleterious affects due to the new wheels.

jplante4 · 01-28-2015, 07:12 PM

We used to do this on the old VWs. I can't remember any adverse effects, but then they were throw away cars. I think I drove mine for 6 months. It did make a difference in the handling.

Mentor · 01-28-2015, 07:24 PM

Quote:

Originally Posted by PushedAround

Without knowing the offsets on those chrome reverse wheels, they may not be as great as you think. What I mean is that the extra width could have been split between inside and outside, and though they are deeper on the outside, some of that width is still towards the inside and so your offsets may not have changed as much as you are thinking. Your front end may still have been operating with-in acceptable limits and so there was little deleterious affects due to the new wheels.

They increased the track width by 12.5 inches as per wheel manufacturers spec.

Mentor · 01-28-2015, 07:28 PM

Quote:

Originally Posted by TXiceman

The wheel bearings are designed fo the load based on the wheel offset as mounted. reversing the wheel will over load the bearings and lead to a bearing failure.

Ken

If you look at the geometry it does not increase the bearing load but reverses the direction.
We have an excellent heavy truck shop here that does a lot of custom work, one day I shall stop by and ask their tech guys but in the meantime input from all here is greatly appreciated however it should be based on some sort of evidence other than guessing. Knowledgeable info would be seriously appreciated.

PushedAround · 01-28-2015, 07:29 PM

Quote:

Originally Posted by Mentor

They increased the track width by 12.5 inches as per wheel manufacturers spec.

Understood, that's a lot. The question is what was their overall width vs the stock ones.

Mentor · 01-28-2015, 07:38 PM

Quote:

Originally Posted by PushedAround

Understood, that's a lot. The question is what was their overall width vs the stock ones.

From tire centreline to centreline it was 12.5 inches wider than with the stock rims. They stuck out enough that a 4" wide flair was put on each fender to help with the splash on the sides of my truck. These were molded FRP extensions built at my shop.

PushedAround · 01-28-2015, 07:44 PM

Quote:

Originally Posted by Mentor

From tire centreline to centreline it was 12.5 inches wider than with the stock rims. They stuck out enough that a 4" wide flair was put on each fender to help with the splash on the sides of my truck. These were molded FRP extensions built at my shop.

Track is measured from outside to outside, but what I was asking was about the width of the wheels themselves. If you did change the offset by 6", that is a tremendous amount and I am surprised that you did not get some serious kickback in the steering under bumps and increased wandering and tramrailling in the highway.