'61 Bonneville 4 door sedan rim size recommendations?

[Bonne61]

Hey there,

Please go easy on me if the answer to my questions are out there somewhere, as I'm just new here🥴

My new car (and first ever classic car) is running on original and stock 14x6" rims, with 205/65x14 tyres. Cute, OEM, all that but not real keen on such small rollers.

So...I'm wanting to put a larger set on it. Would like to go 15x8" all round, but unsure if I'll run into lock clearance when turning? If not, what is the usual? 15x8" rears, 15x7" front? If so, thinking of 245/60 up front & 265/60 rears, but again let me know if this will be too big? Maybe 225/60 & 245/60 may be better? Or should I stay with 15x7" all round to be safe?

I do want the tyres to sit within the guards, as I plan to lower ride height so the sill line is somewhere between top of rim & tyre outer radius. This seems like a good stance, but appears to be reasonable enough to allow me to negotiate most driveways without issues?

Any advice greatly appreciated🙌

Cheers from Paradise🌴

 

[Fitzy]

Hi Paul. Conversely, I wanted to keep the stock wheel size (my 65 Grand Prix also rides on 14s.) My car is also lowered and in order to maintain tyre to guard clearance I'm glad I stuck with 14s. There is about 10mm clearance between the rear tyre sidewall and the guard lip. I test fitted a 15 x 6 stock steel rim and it was never gonna work.

Be aware that like my car, your rims should (check first, Im only assuming) be 5 x 5 PCD. That's 127mm. Don't get caught out - they are NOT the same as a Holden rim.

Having said all that, lotsa blokes get big rims under low cars. I don't know how they manage it - the other guys on the forum will help you out.

You're the second Aussie to join in a week! That's at least 3 of us now,

[Bonne61]

Hey Fitzy,

Thanks for your reply.

From the specs I’ve read mine is 5x 4 ½” (or 5 x 114.3 in our terms)?

However, I will be careful as wouldn’t be happy to lay out $$$ & have to raise it 4” for clearance.

[Last Indian]

3 hours ago, Bonne61 said:

Hey Fitzy,

Thanks for your reply.

From the specs I’ve read mine is 5x 4 ½” (or 5 x 114.3 in our terms)?

However, I will be careful as wouldn’t be happy to lay out $$$ & have to raise it 4” for clearance.

First of all welcome to our obsession Bonne61! 
The very first thing you will need to do is make very accurate measurements of fender clearances, wheelwell clearances, offsets, suspension clearances, etc… if you are going to make changes to the suspension as you indicate that will effect those clearances, make them first! Unless you are really good and know how they will change the geometry of the car, don’t guess! After that start figuring your wheel & tire change. 
That said in general most tire & rim combos usually end up pretty close to the same overall diameter, irrespective of rim size. What affects clearance issues more often than not is way to wide of a rim, like 10” or the offset being to much the wrong way. 
So make good measurements & plug them into the attached link in the appropriate places & you will see what you can & can’t do! 
https://www.wheel-size.com/calc/

An example of my statement is this, my factory rims were P225 16” x 6 with a 43 offset! I had custom rims built. 18” x 8 with a 10 offset for the rears & 23 offset for the fronts. The tires for all 4 rims are P245 45 18”. Yet the over all diameter of the rim & tire combo is exactly the same outside diameter as the 16x6 with P225 tires. All I did was fill as much of the wasted space between the outside fender lip & the inside suspension/inner fender as I could with out making contact with any thing!

these are the original rims/tires

 

these are the new

Edited September 10, 2022 by Last Indian

[Bonne61]

Thank you kind sir😊

I was actually thinking of doing the wheels/tyres first, then do the measure up to see what limits I had left before changing the suspension (if at all).

Like the good gyno says, I’ll look into it 👌🏼

[64 kiwi boni]

Hi Paul, welcome to fp !

Now has anyone mentioned that we love pictures around here ?

I bet Fitzy forgot to say, as he is too busy drinking all our new Zealand beer while he is over here on holiday  !!

Edited September 11, 2022 by 64 kiwi boni

[Fitzy]

9 hours ago, Bonne61 said:

 

From the specs I’ve read mine is 5x 4 ½” (or 5 x 114.3 in our terms)?

I'm going out on a limb here, but does that sound right? I would have thought 5 x 4.75" may have been your size. You probably should measure for yourself. PCD is measured in a specific way: from memory it's from the outside edge of one wheel stud to the inside edge of the one diametrically opposite. Google it to make sure.

Oh, and once again Kiwi is right - photos, photos, photos. Some of our members have exceedingly short attention spans and reading through miles of crap (like the stuff I write) is hard work for them!

Edited September 11, 2022 by Fitzy
Forgot something

[Bonne61]

Hey again,

I too love photos, but we are still awaiting delivery.

Photos will be posted, when we have possession.

Very soon...

[Last Indian]

18 hours ago, Bonne61 said:

Thank you kind sir😊

I was actually thinking of doing the wheels/tyres first, then do the measure up to see what limits I had left before changing the suspension (if at all).

Like the good gyno says, I’ll look into it 👌🏼

I understand why you would want to do it that way. And there is nothing wrong in doing that if you so chose, but, and this is nothing but a question. How are you going to know what to chose for rims & tires for a change you haven’t made? The link that I provided allows you to play with rim & tire size as well as alter suspension parameters to see where there could be interference. 
You indicated that you would like to lower the car. That being said, suspension restrictions always become more limiting when lowered, due to downward travel, not upward & the greatest movement is downward.
So my only reason to mention this method for choosing rims & tires is, unless you have a way & knowledge of how to look at the triangle axis of suspension movement that you intend to make you won’t know what it will be. Even if you make it with your current wheels!

I may be saying this wrong so please pardon me if I am. 

[Bonne61]

18 hours ago, Last Indian said:

I understand why you would want to do it that way. And there is nothing wrong in doing that if you so chose, but, and this is nothing but a question. How are you going to know what to chose for rims & tires for a change you haven’t made? The link that I provided allows you to play with rim & tire size as well as alter suspension parameters to see where there could be interference. 
You indicated that you would like to lower the car. That being said, suspension restrictions always become more limiting when lowered, due to downward travel, not upward & the greatest movement is downward.
So my only reason to mention this method for choosing rims & tires is, unless you have a way & knowledge of how to look at the triangle axis of suspension movement that you intend to make you won’t know what it will be. Even if you make it with your current wheels!

I may be saying this wrong so please pardon me if I am. 

Hey man,

You are absolutely correct, and thank you. Advice is what I've asked for, and this is what I've received.

Have spent the last 24 hours between your link, Mr Google, and an actual show where I've had a REALLY good look at what is fitted to what.

As a result, I've revised my thought process at this stage - going to stick with the 14's initially and just fit as big a tyre as I can to them (I'm thinking 205/60) If still unhappy later on, may shift to 7" wide 14's, or maybe 15's, just so I can get some 225's under it.

However given I'm new to this experience, I think getting a feel for it first is probably the best approach.

Thanks again 🙌🏼

[Last Indian]

Paul as you step through this & weight what you want to do here are a few things that might help.

For instance if you want to push the wheel out & ultimately make the rim wider you can build a cheap wheel spacer to place between the rim & brake this will allow you a visual of what it would look like, plus it allows you to visually see how wide you can make the rim. Also if you want to keep the original wheels, but can’t find them in the width you want you can have the original ones widened! I have done this for a couple guys over the years. You just split the original, cut the two halves apart at the drop in groove, roll a piece of flat hot roll stock, weld it all back together.

Edited September 13, 2022 by Last Indian