Radial tire and ladder bars

Woodfin · 11-01-2023, 08:43 PM

I am obsessing over the setup of this 75 Vette with ladder bars and radial tire. I have built a new subframe inboard of the original frame and have created room for a 30 x 10.5 x 15 Hoosier radial. In addition, am installing a 32" ladder bar. It is a balancing situation with consideration of seat mounting, ladder bar crossmember, ride height, and bar angle.

At this time, I have it all fitted with enough clearance everywhere and with the ladder bar level. If the ladder bar needs to be uphill one bolt hole [which will be 3/4" or about one degree] it will create a problem with the seat clearance.

Some folks are telling me level is OK, others telling me the bars need to run uphill, others telling me one or two degrees down.

In the past with bias tires, I built cars with two degrees down with excellent results.

I am interested in hearing your real experience with ladder bar and radial tire.

NOTE: The car will weigh about 2950 with driver, has a nice, 408 LS engine of about 725 horse, expected performance is 6.0's 1/8 mile. This is a foot brake bracket buildup.

In addition, the track where we will race are good and well prepped.

Adger Smith · 11-02-2023, 06:43 AM

If you are concerned with true radial performance and suspension issues run the PBR's...A lot of bracket racers rave about them.
Performance, longevity without the radial issues is what they claim.

Mike Pearson · 11-02-2023, 07:44 AM

Level or slightly down in the front of the ladder bar is what I run. Up will not work at all. And that is in relationship to the frame not the ground. I run radials and the car works good with that configuration

Woodfin · 11-02-2023, 08:12 PM

Mike, thank you. I plan to set it up just like you suggest and like I have with other buildups. If it does not perform as expected, I will sell the radial tire and install a conventional bias tire.

Ron Miller · 11-05-2023, 03:06 PM

Quote:

Originally Posted by Woodfin

Mike, thank you. I plan to set it up just like you suggest and like I have with other buildups. If it does not perform as expected, I will sell the radial tire and install a conventional bias tire.

Larry,
By chance do you have any build in progress pictures? I would like to see how you set the rear end up and frame rails mod. How wide is the housing?
Thanks,

Woodfin · 11-05-2023, 03:23 PM

Ron, I will be posting some updates soon. Just at this moment, I do not remember the dimensions [I am old] and will check them and post soon.

I "think" it is going to be a good package, and like many things in life, the second one would be easier. I flip flopped around with the design for a while before setting into what I have now. So far, the biggest issue is the driver's seat. The OE seat is too tall, so, no choice other than a low mounted aftermarket seat. I'll post how that works out, it will be a week or two before I get that under construction.

Woodfin · 11-05-2023, 03:25 PM

By tha way, if I have any issues with the radial tire, I will go back to a bias tire. I know a bias tire is consistent and wins races, stand by for radial tire results

Woodfin · 11-05-2023, 07:43 PM

Ron, the new frame is 49 1/2 inches outside to outside. The rear axle assembly is 38 1/2 inches axle flange to axle flange. Also, I have added some update photos. If you want other info let me know.

Ron Miller · 11-08-2023, 07:29 PM

Quote:

Originally Posted by Woodfin

Ron, the new frame is 49 1/2 inches outside to outside. The rear axle assembly is 38 1/2 inches axle flange to axle flange. Also, I have added some update photos. If you want other info let me know.

When you have time I would like to see your progress. What's your link to build pictures?

Woodfin · 11-08-2023, 10:15 PM

https://classracer.com/classforum/sh...ad.php?t=84370

11-01-2023, 08:43 PM	#1
Woodfin Member Join Date: Sep 2006 Location: Kilgore TX Posts: 435 Likes: 5 Liked 74 Times in 39 Posts	Radial tire and ladder bars I am obsessing over the setup of this 75 Vette with ladder bars and radial tire. I have built a new subframe inboard of the original frame and have created room for a 30 x 10.5 x 15 Hoosier radial. In addition, am installing a 32" ladder bar. It is a balancing situation with consideration of seat mounting, ladder bar crossmember, ride height, and bar angle. At this time, I have it all fitted with enough clearance everywhere and with the ladder bar level. If the ladder bar needs to be uphill one bolt hole [which will be 3/4" or about one degree] it will create a problem with the seat clearance. Some folks are telling me level is OK, others telling me the bars need to run uphill, others telling me one or two degrees down. In the past with bias tires, I built cars with two degrees down with excellent results. I am interested in hearing your real experience with ladder bar and radial tire. NOTE: The car will weigh about 2950 with driver, has a nice, 408 LS engine of about 725 horse, expected performance is 6.0's 1/8 mile. This is a foot brake bracket buildup. In addition, the track where we will race are good and well prepped.

11-02-2023, 06:43 AM	#2
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,364 Likes: 456 Liked 693 Times in 269 Posts	Re: Radial tire and ladder bars If you are concerned with true radial performance and suspension issues run the PBR's...A lot of bracket racers rave about them. Performance, longevity without the radial issues is what they claim. __________________ Adger Smith (Former SS)

11-02-2023, 07:44 AM	#3
Mike Pearson VIP Member Join Date: Mar 2007 Posts: 2,331 Likes: 548 Liked 1,658 Times in 508 Posts	Re: Radial tire and ladder bars Level or slightly down in the front of the ladder bar is what I run. Up will not work at all. And that is in relationship to the frame not the ground. I run radials and the car works good with that configuration __________________ Mike Pearson 2485 SS

11-02-2023, 08:12 PM	#4
Woodfin Member Join Date: Sep 2006 Location: Kilgore TX Posts: 435 Likes: 5 Liked 74 Times in 39 Posts	Re: Radial tire and ladder bars Mike, thank you. I plan to set it up just like you suggest and like I have with other buildups. If it does not perform as expected, I will sell the radial tire and install a conventional bias tire.

11-05-2023, 03:23 PM	#6
Woodfin Member Join Date: Sep 2006 Location: Kilgore TX Posts: 435 Likes: 5 Liked 74 Times in 39 Posts	Re: Radial tire and ladder bars Ron, I will be posting some updates soon. Just at this moment, I do not remember the dimensions [I am old] and will check them and post soon. I "think" it is going to be a good package, and like many things in life, the second one would be easier. I flip flopped around with the design for a while before setting into what I have now. So far, the biggest issue is the driver's seat. The OE seat is too tall, so, no choice other than a low mounted aftermarket seat. I'll post how that works out, it will be a week or two before I get that under construction.

11-05-2023, 03:25 PM	#7
Woodfin Member Join Date: Sep 2006 Location: Kilgore TX Posts: 435 Likes: 5 Liked 74 Times in 39 Posts	Re: Radial tire and ladder bars By tha way, if I have any issues with the radial tire, I will go back to a bias tire. I know a bias tire is consistent and wins races, stand by for radial tire results

11-05-2023, 07:43 PM	#8
Woodfin Member Join Date: Sep 2006 Location: Kilgore TX Posts: 435 Likes: 5 Liked 74 Times in 39 Posts	Re: Radial tire and ladder bars Ron, the new frame is 49 1/2 inches outside to outside. The rear axle assembly is 38 1/2 inches axle flange to axle flange. Also, I have added some update photos. If you want other info let me know.

11-08-2023, 10:15 PM	#10
Woodfin Member Join Date: Sep 2006 Location: Kilgore TX Posts: 435 Likes: 5 Liked 74 Times in 39 Posts	Re: Radial tire and ladder bars https://classracer.com/classforum/sh...ad.php?t=84370