Tires For a '71
Thread Starter
Heel & Toe
Joined: Jul 2013
Posts: 15
Likes: 0
Tires For a '71
Hello,
I'm looking for new tires for my '71 and I've decieded on the BFGoodrich Radial T/A's and will be putting the 225/70/R15's on. I currently have four Goodyear Eagle GT's and have determined that they are quite old and I have also determined that the spare is the original.
Today, I took the Goodyear off the right rear to see if it would fit in the tire carrier( the BFGoodrich's are the same size) and determined that the 225's are too wide for the carrier. So, I was thinking of getting four 225's for each corner and getting one 215 for the spare. Does my logic make sense or will the 215 be a bad idea in the event that the spare tire needs to be used?
Any help or ideas will be very helpful.
Thanks everybody, take care,
Jason
I'm looking for new tires for my '71 and I've decieded on the BFGoodrich Radial T/A's and will be putting the 225/70/R15's on. I currently have four Goodyear Eagle GT's and have determined that they are quite old and I have also determined that the spare is the original.
Today, I took the Goodyear off the right rear to see if it would fit in the tire carrier( the BFGoodrich's are the same size) and determined that the 225's are too wide for the carrier. So, I was thinking of getting four 225's for each corner and getting one 215 for the spare. Does my logic make sense or will the 215 be a bad idea in the event that the spare tire needs to be used?
Any help or ideas will be very helpful.
Thanks everybody, take care,
Jason
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
The two long bolts that are in your frame that the lower portion of your spare tire carrier hangs on when it is down.... can be adjusted to accommodate the wider tire.
BECAUSE..having your spare be a different size is one thing...BUT...how are your going to stow away the flat tire when you need to use the spare??? Because I have had them come in my shop with the flat tire in the passenger seat.
DUB
BECAUSE..having your spare be a different size is one thing...BUT...how are your going to stow away the flat tire when you need to use the spare??? Because I have had them come in my shop with the flat tire in the passenger seat.
DUB
Last edited by DUB; Jan 16, 2016 at 06:00 PM.
Drifting
Joined: Jul 2002
Posts: 1,995
Likes: 110
From: Garland Texas
Jason,
The spare tire tub is adjustable. Loosen the two long bolts at the front of the tub to adjust for tire width.
Mike
Dub beat me to it.
The spare tire tub is adjustable. Loosen the two long bolts at the front of the tub to adjust for tire width.
Mike
Dub beat me to it.
Last edited by tracdogg2; Jan 16, 2016 at 06:01 PM.
Thread Starter
Heel & Toe
Joined: Jul 2013
Posts: 15
Likes: 0
Cheers!
Team Owner
Joined: Sep 2006
Posts: 31,283
Likes: 4,373
From: Westminster Maryland
Hi JPC,
I believe you'll find that single bolt at the rear of the tub is adjustable too.
There's a threaded 'slug' that the bolt threads through. This 'slug' gives about 1 1/2" of adjustment.
The forward bolts are adjusted after loosening their lock nuts.
Good Luck!
Regards,
Alan
The rear bolt… as you tighten it up the extra length passes up into a opening in the rear crossmember.
The 'slug' looks like the end of a barrel in this picture. (Maybe it's called a 'barrel nut'?)
One of the 2 forward bolts showing the lock nut and some of the adjustment on the bolt.
I believe you'll find that single bolt at the rear of the tub is adjustable too.
There's a threaded 'slug' that the bolt threads through. This 'slug' gives about 1 1/2" of adjustment.
The forward bolts are adjusted after loosening their lock nuts.
Good Luck!
Regards,
Alan
The rear bolt… as you tighten it up the extra length passes up into a opening in the rear crossmember.
The 'slug' looks like the end of a barrel in this picture. (Maybe it's called a 'barrel nut'?)
One of the 2 forward bolts showing the lock nut and some of the adjustment on the bolt.
Last edited by Alan 71; Jan 16, 2016 at 06:44 PM.
Thread Starter
Heel & Toe
Joined: Jul 2013
Posts: 15
Likes: 0
Hi JPC,
I believe you'll find that single bolt at the rear of the tub is adjustable too.
There's a threaded 'slug' that the bolt threads through. This 'slug' gives about 1 1/2" of adjustment.
The forward bolts are adjusted after loosening their lock nuts.
Good Luck!
Regards,
Alan
The rear bolt… as you tighten it up the extra length passes up into a opening in the rear crossmember.
One of the 2 forward bolts showing the lock nut and some of the adjustment on the bolt.
I believe you'll find that single bolt at the rear of the tub is adjustable too.
There's a threaded 'slug' that the bolt threads through. This 'slug' gives about 1 1/2" of adjustment.
The forward bolts are adjusted after loosening their lock nuts.
Good Luck!
Regards,
Alan
The rear bolt… as you tighten it up the extra length passes up into a opening in the rear crossmember.
One of the 2 forward bolts showing the lock nut and some of the adjustment on the bolt.
Cheers!
Drifting
Joined: Jan 2004
Posts: 1,468
Likes: 223
From: Sherman CT
2023 C3 of the Year Finalist - Unmodified
2019 C3 of Year Finalist (stock)
St. Jude Donor '24-'25-'26
I have a 1972, and my BFG radial T/A spare which is 225:70 R15 fits nicely in the spare tire tub, I'm sure you can get it to fit in there
Regards
Roy
Regards
Roy
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
F70-15 tires are equivalent width to a 215 radial tires, so 215's should easily fit in the tub. I have 235R60-15's all around on my '71 coupe and the outer diameter of that tire is the same as the F70-15's. I'm pretty sure the spare tire tub can handle 1 more inch of width with the adjustment it has. (My tire tub has ONLY held the [unused]factory original spare tire, however.)
P.S. I highly recommend going with 235R60-15's. That's as wide as the front wheelwells will accept without having some risk of rubbing during full-turns.
P.S. I highly recommend going with 235R60-15's. That's as wide as the front wheelwells will accept without having some risk of rubbing during full-turns.
Last edited by 7T1vette; Jan 17, 2016 at 01:23 AM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
Not knowing what you had on the car BEFORE you put a new set on....if you are changing the tire size enough...mainly the circumference...it can throw off your speedometer.
Also...not knowing if the car has power steering or not....having a wider contact patch of thread can cause for some more effort in turning.....but as most people know who have manual steering. You get the car moving and then begin turning the steering wheel.
I did not want to comment on the size of the tire chosen is different to what the car originally had when converted as like '7T1vette' mentioned.
DUB
Also...not knowing if the car has power steering or not....having a wider contact patch of thread can cause for some more effort in turning.....but as most people know who have manual steering. You get the car moving and then begin turning the steering wheel.
I did not want to comment on the size of the tire chosen is different to what the car originally had when converted as like '7T1vette' mentioned.
DUB
Thread Starter
Heel & Toe
Joined: Jul 2013
Posts: 15
Likes: 0
I got the Goodyear to fit after dropping all the bolts, but I really had to push up on the carrier and I really had to pull on the back bolt to get it all to work. Is this the way your spare tire fits?
The front bolts have 3/8" threaded into the frame, I dont want to take more out and the back bolt is threaded out as far as it can.
7T1, I'll look into those tires, but I like the way the 70 series fills the wheel well. Could you attach a picture so that I may see how it looks?
Thanks fellas!
The front bolts have 3/8" threaded into the frame, I dont want to take more out and the back bolt is threaded out as far as it can.
7T1, I'll look into those tires, but I like the way the 70 series fills the wheel well. Could you attach a picture so that I may see how it looks?
Thanks fellas!
Last edited by JPCorvetteC3; Jan 17, 2016 at 05:48 PM.
Thread Starter
Heel & Toe
Joined: Jul 2013
Posts: 15
Likes: 0
Not knowing what you had on the car BEFORE you put a new set on....if you are changing the tire size enough...mainly the circumference...it can throw off your speedometer.
Also...not knowing if the car has power steering or not....having a wider contact patch of thread can cause for some more effort in turning.....but as most people know who have manual steering. You get the car moving and then begin turning the steering wheel.
I did not want to comment on the size of the tire chosen is different to what the car originally had when converted as like '7T1vette' mentioned.
DUB
Also...not knowing if the car has power steering or not....having a wider contact patch of thread can cause for some more effort in turning.....but as most people know who have manual steering. You get the car moving and then begin turning the steering wheel.
I did not want to comment on the size of the tire chosen is different to what the car originally had when converted as like '7T1vette' mentioned.
DUB
The car came with the 225 Goodyear's and I was thinking of putting the 225 BFG's on as a replacement. The car has manual steering, so I understand your concern with a wider tire.
Does anybody know if there is an aftermarket front bolt with a longer thread?
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
It will not necessarily be longer threads....but the distance of the bolt from where the threads stop and the end of the bolts that touches the tire carrier.
I know many things....but the lengths of the front bolts for the spare tire carriers is something that I do not know right off the top of my head. SO...the length of it needs to be known...and you may have to get a few to see which one will work. You may have to go back the the 1963-1967 era and look at them.
Some of these tire carrier bolts go all the way in and stop...and others look like what 'Alan71' shown in his photo where you can see that the jamb nut can adjust the tire carrier bolt.
DUB
Last edited by DUB; Jan 17, 2016 at 06:00 PM.
Thread Starter
Heel & Toe
Joined: Jul 2013
Posts: 15
Likes: 0
It will not necessarily be longer threads....but the distance of the bolt from where the threads stop and the end of the bolts that touches the tire carrier.
I know many things....but the lengths of the front bolts for the spare tire carriers is something that I do not know right off the top of my head. SO...the length of it needs to be known...and you may have to get a few to see which one will work. You may have to go back the the 1963-1967 era and look at them.
Some of these tire carrier bolts go all the way in and stop...and others look like what 'Alan71' shown in his photo where you can see that the jamb nut can adjust the tire carrier bolt.
DUB
I know many things....but the lengths of the front bolts for the spare tire carriers is something that I do not know right off the top of my head. SO...the length of it needs to be known...and you may have to get a few to see which one will work. You may have to go back the the 1963-1967 era and look at them.
Some of these tire carrier bolts go all the way in and stop...and others look like what 'Alan71' shown in his photo where you can see that the jamb nut can adjust the tire carrier bolt.
DUB
Last edited by JPCorvetteC3; Jan 17, 2016 at 06:37 PM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
You must extend the two 'forward' tub retaining bolts to get the most depth out of that spare tub. You can't just get enough by extending adjustment on the rear bolt.
Here's a better photo of my car with 235R60-15's on it...
Here's a better photo of my car with 235R60-15's on it...
Safety Car
Joined: Sep 2013
Posts: 4,355
Likes: 2,633
From: Draper Utah
245R60-15's also fit with no issues on early year C3's and is a BF Goodrich size.
Last edited by Iceaxe; Jan 17, 2016 at 09:26 PM.
Racer
Joined: Nov 2005
Posts: 285
Likes: 88
From: Pennsylvania
2016 C3 of Year Finalist
I think you're on the right track with 225/70's, they look great on early C3's, and according to some of the posts above, it seems they will fit in the tub of the carrier.
Here are some overall diameter comparisons of the various tire sizes being used on early C3's nowadays:
235/60/15 26.1"
245/60/15 26.57"
255/60/15 27.05"
275/60/15 27.99" (have only seen these used on the rear)
215/70/15 26.85"
225/70/15 27.4"
Here are the dimensions of the original type F70-15:
(Goodyear Speedway Wide Tread)
overall diameter= 26.97"
section width= 8.95"
tread= 6.5"
235/60's are OK up front, but look a bit too small in the rear wheel wells of a C3 - they are actually almost an inch less in diameter than an original size F70-15.
Here is a tire size comparison calculator with all dimensions:
https://www.tacomaworld.com/tirecalc
Best of luck!
Here are some overall diameter comparisons of the various tire sizes being used on early C3's nowadays:
235/60/15 26.1"
245/60/15 26.57"
255/60/15 27.05"
275/60/15 27.99" (have only seen these used on the rear)
215/70/15 26.85"
225/70/15 27.4"
Here are the dimensions of the original type F70-15:
(Goodyear Speedway Wide Tread)
overall diameter= 26.97"
section width= 8.95"
tread= 6.5"
235/60's are OK up front, but look a bit too small in the rear wheel wells of a C3 - they are actually almost an inch less in diameter than an original size F70-15.
Here is a tire size comparison calculator with all dimensions:
https://www.tacomaworld.com/tirecalc
Best of luck!
Last edited by Bally; Jan 18, 2016 at 12:18 AM.
Safety Car
Joined: Sep 2013
Posts: 4,355
Likes: 2,633
From: Draper Utah
When I was in high school in the early 70's I worked in a tire shop and the most popular early C3 Corvette tire replacement was a G60-15, which is almost a direct replacement for a 246/60-15, and never had interference issues. We did hundreds of sets of tires.
G60-15 - 26.4 diameter 9.7 section
245/60-15 - 26.6 diameter 9.8 section
YMMV
Last edited by Iceaxe; Jan 18, 2016 at 05:05 PM.
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
Hopefully if you get the longer bolts it will correct your spare tire issue...which I believe it should.
DUB
Thread Starter
Heel & Toe
Joined: Jul 2013
Posts: 15
Likes: 0
I lowered the front bolts again and got the 225 Goodyear to fit! There wasn't much tthread threaded into the frame though, maybe a 1/4"? I tightened up the nut and lock nut, it seems fine. I was going to stop in at my local Corvette shop and see what they recomend on this issue. Eitherway, I can finally get some new rubber for the car.
Thanks for all of your help, it has not been wasted.
Thanks for all of your help, it has not been wasted.
Last edited by JPCorvetteC3; Jan 20, 2016 at 11:31 PM.