Rear tire flex and tire speed rating

[427HRmike]

Hello,

 I have a 64 fairlane with a narrowed 8 inch rear to clear 15x8 rims with p265/50r15 tires in the wheel well. I have approx. 7/8" of clearance inside and outside when sitting in the garage, however the inside of the tires (only)are rubbing slightly on the lower front inner wheel-well after driving it. Before I try a panhard or change the rubber bushings out to polyurethane to help eliminate rear end movement I was wondering if  anyone hear has experience in with going from a "S" speed rated tire to a "H" rated and how much flex can actually be eliminated. I don't need much

Thanks Mike

[427HRmike]

Pictures

[TomP]

I'm surprised a 265 even fits if the inner wheelwells are still stock. I cut mine and moved it against the frame rail and added a strip around it. If it rubs the inner on the part that goes down at an angle ahead of the axle you can bend that lip inward so the tire doesn't catch it.
 They aren't rubbing where the back of the rocker panel meets the wheelwell? I think those tires may be short enough to avoid that but on mine I had to cut the rocker panel end and make a new lip.

 I don't think the different speed rating will affect flex at all. Some brands and styles are stiffer than others. Generally the V speed rated tires are stiffer and lower profiles have to be stiffer too. Not that would be any selection for that in a 15" size.

[427HRmike]

Thanks Tom

Wheel wells are stock and hopefully in the next two pictures you can see where they are rubbing. Its a little darker on the area of contact above where I have rolled the lip in the best I can.

No rubbing at the rocker panel (outside of tire) at all. The clearance is almost the same on the outside so I don't know why only the insides rub. I found a tire that is 1 inch taller and not quite as wide but I don't want the rocker panel problem next, plus those tire are M/T and $225 each!

Bummer. I'm limited on even the tire size I have. I have only found p265/50R15 in Hankook "S" rated and a Galaxy R1 "H" rated tire by Vitour? Not sure if the Vitours are even good but I was hoping they would flex less.

I hear you on the lower profiles being much better, but I can't do that to this car haha

[427HRmike]

More Pictures

[427HRmike]

I hope these pictures are working. I can't figure out how to down size them.

[427HRmike]

Anybody heard if these are any good.

https://www.performanceplustire.com/tires-for-sale/vitour-tires/galaxy-r1-5/ty:Tire:ts:265-50-15/?gclid=EAIaIQobChMI4f6k3Meb4QIVhRh9Ch3SFw_LEAQYBSABEgIpxvD_BwE

[Falcon67]

I have that problem on the Falcon with slicks.  Sorry, I just modified the ends of the rocker panels with a sledge hammer.  I was at a race, no time for precision body work.  That said, there should be effectively zero tire grown with any street tire.  I do not have any issues with drag radials as they have pretty much zero growth at speed.  My inner lips are rolled and no contact issues.  I'd be thinking your rear housing is not centered well or is moving around more than it should. 

[TomP]

The 64 Fairlane rear spring bushings are soft. What happens is under acceleration it squashes them moving the rear end forward. It is worse if you still have the rubber isolators under the U bolts.

[427HRmike]

Thank you "Falcon67" Bummer I was hoping a higher speed rated tire would be a little stiffer. The housing seems centered to me. Both tires have the same clearance on each side while sitting in the garage,and both tires have the same slight rubs marks on the inside only. Outside sidewalls have no rub marks.

"TomP" The leafs are new but have rubber bushings. I guess I will try some polyurethane bushings and cross my fingers. I plan on removing this housing and axles soon for a different rim set up. The rubber isolators have been removed.

[427HRmike]

Picture

[57 lima bean]

Sounds like your housing is bent.Had a friend tell me years ago that under acceleration mine would load to one side.Sure enough,it was way off. 

[427HRmike]

Hmmmmmmm? I would think I would have a problem on one side if it was bent. My problem is identical on both sides and only rubs slightly when cornering. It seems to me the housing is moving or the s rated tires are flexing. I have read before that high rated tires do not flex as much and was hoping someone here might have had experience with this. Not saying you are wrong,I guess its possible. But this rear end was narrowed just a few years ago and has new Dutchman axles.