Wheel backspacing for 69 B body / Super Bee

[68383]

For all you B body guys out there-

I'm considering 15x8 rear wheels for my '69 Super Bee. Summit has the wheels with 4" or 4.5" backspacing. The fronts I'm looking at are 15x6 with 3.75" backspacing.

Can anyone offer some insight on which backspacing would be best?

Thanks, guys.

 

[dbowperson]

I just mounted a set of AR Torque Thrusts on our 69 Bee. I went with 15x7 front with 3.75 BS, and 15x8 with 3.75 BS. Tires are 235/60-15 front and 275/60-15 rear. Everything fits with no problem, and looks great.

 

[moparstuart]

I just mounted a set of AR Torque Thrusts on our 69 Bee. I went with 15x7 front with 3.75 BS, and 15x8 with 3.75 BS. Tires are 235/60-15 front and 275/60-15 rear. Everything fits with no problem, and looks great.

very nice :rolling::rolling::rolling:

 

[68383]

Any recommendations on tire width and height? If I remember correctly, close to stock tires would be 225/70R15. Do I want tires that are that tall with my 3.91 gears? Seems like most people mention 60s rather than 70s.

I also put in a pair of XHD springs last year and would like it if the car had a slight rake, but nothing ridiculous

 

[dbowperson]

I think 70 is a bit tall for a 15" tire, in my opinion. The tires we just put on replaced a set of F70 wide ovals, and I did not think they looked right. I know they are period correct, but just not my cup-of-tea. I like a tall sidewall, but that was too much. A 255/60-15 rear tire is 28" tall, which is pretty much stock height. With a 3.91 gear, you might want a slightly taller tire (275/60-15) if you drive much on the highway, because you will be screaming at 70 MPH. As a for instance, I have a 29" tall tire (255/60-17) on my Challenger, and I turn about 3,100 RPM at 70 with a 3.91 gear.

 

[68383]

Thanks for the info. and opinions, guys. I appreciate it.

I really want a 6” rim for the front. I had a 7” rim on the front of my old Charger and the wheels and tires (235/70s) just looked too wide to me. With one of the companies I'm researching, it looks like the best size I can get closest to a 6” width is 205/60R15. The Coronet in the picture below has 215/70R15s, but I don't like how they seem to bulge in the front:

The person at the tire company mentioned, "The ideal is to have the rim width the same as the tread width. However, they can vary plus or minus 1 1/2 inch. It is all a matter of personal preference. And even this is based on appearance and not safety or performance."

Any other input on a tire size for the front?

My plan for the rear is 275/60R15s for the rear. I had those on my Charger, liked them, and several people have recommended the size as well.

I also like the look of a slight rake, but nothing overly dramatic.

Thanks,

 

[dbowperson]

The Bee is a big mother car with huge fenders. I would be afraid that a 6" wheel with 205 tires would look too skinny, but that's just me. The F70 tires we replaced had a 7.5" tread width, but had a taller side wall so that didn't help. It's tough to tell in my picture above because my driveway has a decent slope down, but the rake with our setup is pretty good. I need to get some pictures with it on a flat surface.

 

[68383]

Here's what I heard from the tire guy:

"The tread width of the tire effects the look of the tire the 6" rim. The closer the tread width is to 6" the better the tire will look on the 6" rim. This would lead me to consider the 215/65R15."

 

[68383]

Well, to complicate matters, I got some more advice. The person is an advocate for four of the same size wheels and tires. What do you think? It seems to make sense to me:

1) I like to rotate them so hole shots, alignment issues are not taxing on the rubber and they last allot longer, like three or four times longer.

2) I like to drive on the highway and not just under 40 and handling sucks at 50 plus with miss matched tires which is not what the suspension and steering was built for. Basically the over steer is bad and exponentially worse as the speed increases and or you get stuck in wet road conditions.

3) High speed hard stops often bring the back end of the car around when they lock up and the rears are larger then the fronts as the prop valves and shoes/discs assume equal bias between front and rear friction/contact areas and nobody ever re-balances front and rear proportioning bias when they do this. If you have ever experienced this it's pretty scary and your only real option to get her going straight is to back of the brakes until they stop skidding.

4) Also changing rear only back spacing is a cheat way to get massive meaties in the rear wells but also changes the handling and front to rear track balance again hosing up the mid to higher speed handling even more so.

 

[dbowperson]

I think you are over-thinking it. You could get different sizes front and back before, and that should not factor into turning, braking, driving, etc. Our cars (Challenger, Super Bee, Charger) all have larger rear tires than the front, and we have never had problems like you are describing. If that is what you are experiencing, then I would say you have major suspension/brake problems that need to be addressed. With regards to life expectancy, how often will you be driving the car? If it is a weekend toy with light driving through the year, the tread will outlast the weathering of the tire. Every sports car out there has larger rear tires than front, with most of them have taller rear wheels than front.

As far as going with the same size tires all around, your best bet will probably be 15x7 wheels with 255/60-15 tires, but they might rub on the front, but probably not. Good luck with whatever you get.

 

[68383]

I think you are over-thinking it.

That was advice from another guy I know.

Personally, I'm thinking 15x6s all around with 225/70R15s for daily duty. Then a set of wide wheels and slicks for the track.

 

[dbowperson]

27.4" tall tire on the front might make it look like it is trying to lift off, and you won't have any rake unless you have air shocks, but if daily driving is your goal, then that should work.

 

[68383]

A few turns on the tortion bars could also create a rake, right?

 

[dbowperson]

Yes, but more than a few turns and you should get an alignment.