Rear Knock Off wheels too Wide

[Chicagowil]

Sometime quite a while back I picked up a set of used 5 pin Knock off wheels including the universal (Chevy or Ford) hubs. They are 7.5 X 15 & 9.5 X 15 wheels. I finally got around to trying them on my CR1. Now I find the front work fine but the rears are too wide! They stick out of the rear fender almost 2 inches. Over an inch of that alone is the adaptor.

So now I have to either choose different wheels like the bolt on style wheel, keep the (IMHO the original, ugly) black steel 8" wheels that Classic Roadsters supplied, or replace the rear wheels with 7.5 " wide knock offs.

Just purchasing two of the knock off wheels is more than the cost of the whole set with adaptors that I already purchased.

Its not like I'm trying to build an exact replica, obvious since I purchased a CR1!

Suggestions?

Thom

[LMH]

What kind of adapter are you using? The five pin adapters I had on my Hurricane were less than 1/2" thick. Can you post a photo or two?
Larry

[Chicagowil]

Will try to post Thursday afternoon. Wife has to go to Chicago to get her 2nd Covid vaccine tomorrow.

Thom

[undy]

When buying ANY wheel for a Cobra checking and specifying wheel back spacing is critical since there's no standardization between different manufacturers. This determines how far your wheel sits within the wheel well and subsequently how far it sits outside too. It's just not as simple as... 7.5 X 15 & 9.5 X 15. It sounds like your rears won't be usable.

[Chicagowil]

I remounted the knock off on one rear side (yes, I know it is on the wrong side- just temp mock up). It turns out the due to the snug fit of the pin drives- it does only add 1/2" to the hub.

But that still left the wheel sticking out 1 1/2". So I purchased some 2" fiberglass flairs. I temp mounted one onto the rear fender just to see how it would look. They are normally a screw-on for race cars and come in black fiberglass.

Click on a photo to see it in a larger view.

If I keep the wider rear wheels I need to increase the fender width. I could glue them on, and add glass filler to blend them into the fender. Trying to decide if it will look OK.



It will cover the wheel at the top.

There is a lot of space above the tire and wheel arch on the rear as the car sits now.


As you can see from this finished CR on a side view, the rear arch is very high, So I think the added flare will actually improve the sizing.



Do like having the 9.5" rear wheel vs the 7.5" that would fit under the stock fender. I will just have to work with the fiberglass to make sure the added flare looks not like an add-on.

Thom

[8litercobra]

There's always more than one way to skin a cat; each to his own and all that!
Checking for proper backspacing/fit, as Undy brought up, is the lesson here.

[Chicagowil]

Originally Posted by 8litercobra

There's always more than one way to skin a cat; each to his own and all that!
Checking for proper backspacing/fit, as Undy brought up, is the lesson here.

I agree that the proper choice is the way to go. The difference here is that Classic Roadster used a "narrow" version of the 427 body design, much like the non-SC street version of AC's bodies. It was so early on shortly after I had acquired the CR1 (with it in storage and not really accessible) that I thought "take a chance that they will fit".

But with that said- I had gotten such a deal on the setup that even if I decide to stay with the stock fender line and purchase 2 new rear wheels in a size that will fit, I will still be in for less cost then if I had purchased 4ea- 5 bolt-on style wheels.

I have also thought about just reselling this setup and purchasing 4 new bolt-on wheels that will fit under the fenders.

No undoable mods have been made to the fenders as of yet.

More to come.

Thom

[mvanhorn8893]

I would verify that the wheel goes all the way onto the adapter with a feeler gauge. I'd also measure thee depths of the pin holes on the back side of the wheels. If they have enough depth,you might have that surface machined down and re chamfered or radiused to mate to the adapter to bring the wheel back into the right position.

[eschaider]

Originally Posted by mvanhorn8893

I would verify that the wheel goes all the way onto the adapter with a feeler gauge. I'd also measure thee depths of the pin holes on the back side of the wheels. If they have enough depth,you might have that surface machined down and re chamfered or radiused to mate to the adapter to bring the wheel back into the right position.

You could also buy, make or modify your adapters to be thinner.


Ed

[cycleguy55]

Originally Posted by eschaider

You could also buy, make or modify your adapters to be thinner.


Ed

OP indicated the adapters add only 1/2".

[cycleguy55]

Originally Posted by Chicagowil

I agree that the proper choice is the way to go. The difference here is that Classic Roadster used a "narrow" version of the 427 body design, much like the non-SC street version of AC's bodies. It was so early on shortly after I had acquired the CR1 (with it in storage and not really accessible) that I thought "take a chance that they will fit".

But with that said- I had gotten such a deal on the setup that even if I decide to stay with the stock fender line and purchase 2 new rear wheels in a size that will fit, I will still be in for less cost then if I had purchased 4ea- 5 bolt-on style wheels.

I have also thought about just reselling this setup and purchasing 4 new bolt-on wheels that will fit under the fenders.

No undoable mods have been made to the fenders as of yet.

More to come.

Thom

While getting wheels with the correct backspace is likely the best solution, there are others in addition to the fender flare idea.

Are you using a live axle (e.g. Ford 9")? Have you thought about getting it narrowed?

[Chicagowil]

Originally Posted by cycleguy55

While getting wheels with the correct backspace is likely the best solution, there are others in addition to the fender flare idea.

Are you using a live axle (e.g. Ford 9")? Have you thought about getting it narrowed?

I did look at that, but with using the Mustang 8.8 axle with its swing arms, it expands the problem into new geometry for the arm mounts.

The easiest solution is to get two Trigo 427 Cobra 5-Lug Wheels in the 7.5" width to match the front and sell my two Cobra2 9.5" X 15" rear wheels. The 7.5" width does not allow as much rubber but its backspacing and adapter does make it move out a bit ore to the outside edge of the fender then the original steel wheel the car came with.

One I used my lead hammer on the knock-off- the wheel sets right into place. But the 9.5" width with the 1/2" adapter and the backset of the Cobra2 wheel pushes the edge of the wheel out beyond the fender edge by 1.5".

I did look at the Rocket Wheels Sunburst Wheels. They are a bolt on with the look of the original Sunburst style. Love the look but more costly.

I have some time to choose the "next step" for the wheels. I have decided not to add the flair- just don't like the look of it. Just needed to make sure before it goes off to the paint shop soon!

Thom

[cycleguy55]

Originally Posted by Chicagowil

I did look at that, but with using the Mustang 8.8 axle with its swing arms, it expands the problem into new geometry for the arm mounts.

The easiest solution is to get two Trigo 427 Cobra 5-Lug Wheels in the 7.5" width to match the front and sell my two Cobra2 9.5" X 15" rear wheels. The 7.5" width does not allow as much rubber but its backspacing and adapter does make it move out a bit ore to the outside edge of the fender then the original steel wheel the car came with.

One I used my lead hammer on the knock-off- the wheel sets right into place. But the 9.5" width with the 1/2" adapter and the backset of the Cobra2 wheel pushes the edge of the wheel out beyond the fender edge by 1.5".

I did look at the Rocket Wheels Sunburst Wheels. They are a bolt on with the look of the original Sunburst style. Love the look but more costly.

I have some time to choose the "next step" for the wheels. I have decided not to add the flair- just don't like the look of it. Just needed to make sure before it goes off to the paint shop soon!

Thom

If I was ordering a couple of new wheels I'd get wider wheels with the correct offset / backspacing. Vintage Wheels does custom backspacing, though options may be limited (per their website). https://vintagewheelsus.com/index.ph...index&cPath=18

[Chicagowil]

I did reach out to Vintage Wheels and they will assist me with getting replacement rear wheels for my needs. Very quick response and very helpful! I'm impressed!

If any one is looking for a pair of used 9.5"X15" 5 pin drive wheels- let me know!

Thom

[8litercobra]

You will be very happy with your decision. Vintage made two custom backspace wheels for me that worked perfectly. Wider wheel/tire combo was brought just inside the fender. Make sure that the extra backspace will clear all bracketry and spring perches.....but Bob will have warned you to do all that!

[cycleguy55]

Originally Posted by Chicagowil

I did reach out to Vintage Wheels and they will assist me with getting replacement rear wheels for my needs. Very quick response and very helpful! I'm impressed!

If any one is looking for a pair of used 9.5"X15" 5 pin drive wheels- let me know!

Thom

Excellent news! Please post photos once you have them installed.

[eschaider]

Originally Posted by cycleguy55

OP indicated the adapters add only 1/2".

You're right Brian, my bad. Somehow I got it into my head the adapters were the 1.5" dimension which is actually the amount the OP indicates the wheels protrude.

To the OP,

While flaring the fender will cover the tire / wheel combo you are potentially changing the appearance of the body in a significant way. Even if you are not attempting a period correct car, there are visual cue's and an expected external apearance that potential buyers look for when they are making buying decisions.

Your flare enhancement is likely to violate those unspoken expectations and diminish both the visual appeal of your car to potential buyers and also the resale value. I would try to find a different solution.


Ed

[joyridin']

Originally Posted by Chicagowil

I did look at that, but with using the Mustang 8.8 axle with its swing arms, it expands the problem into new geometry for the arm mounts.

The easiest solution is to get two Trigo 427 Cobra 5-Lug Wheels in the 7.5" width to match the front and sell my two Cobra2 9.5" X 15" rear wheels. The 7.5" width does not allow as much rubber but its backspacing and adapter does make it move out a bit ore to the outside edge of the fender then the original steel wheel the car came with.

One I used my lead hammer on the knock-off- the wheel sets right into place. But the 9.5" width with the 1/2" adapter and the backset of the Cobra2 wheel pushes the edge of the wheel out beyond the fender edge by 1.5".

I did look at the Rocket Wheels Sunburst Wheels. They are a bolt on with the look of the original Sunburst style. Love the look but more costly.

I have some time to choose the "next step" for the wheels. I have decided not to add the flair- just don't like the look of it. Just needed to make sure before it goes off to the paint shop soon!

Thom

Just for future reference, I had my 8.8 narrowed 1.5" on each side without any issues. I did not even have to change the factory control arm mounting. I gained an extra 3/4" per side by removing the factory axles that had the tone ring on them (they are 3/4" longer than standard Fox axles). All in all, I gained 2"/side.

[Chicagowil]

Originally Posted by joyridin'

Just for future reference, I had my 8.8 narrowed 1.5" on each side without any issues. I did not even have to change the factory control arm mounting. I gained an extra 3/4" per side by removing the factory axles that had the tone ring on them (they are 3/4" longer than standard Fox axles). All in all, I gained 2"/side.

That may be the cheaper and easier way to go! Was your 8.8 a drum or disc brake rear? And what did you use for axles?

Mine is a drum. I will pull the wheels and take a closer look.

Guess I am a little confused what is a "tone ring"?

Thom

[joyridin']

Mine was a disk unit. The tone rings were used on the disk brake axles. They were mounted on the axle between the housing and the flange for the anti-lock brakes. The housings for the drum and disk rear-ends were the same, but due to the disk brakes, the rear ends were wider.

Forte makes disk adapters as well as North Racecars. North Racecars were cheaper because they made them out of steel if I recall. I upgraded from the factory 10.5" to the 11.66" Mustang Cobra brakes on the rear. Real easy to do. I had 17" rims. Not sure of the 11.66" brakes will fit with 15" wheels.

I bought the axles from Moser if I recall. I ordered them with the disk brake hub instead of the drum hub as the disk hub is larger. The axles were surprisingly inexpensive. I guess people did it a lot.

So, I had the housing narrowed, bought the disk adapters, and put in new shortened axles. Then I had 11.66" rear disks with the narrowed rear.