NSW Corvettes

Technical Tips => Brakes, Suspensions, Steering, Wheels & Tyres => Topic started by: Philip on September 15, 2023, 01:39:09 PM

Title: Spare tyre size for 76C3
Post by: Philip on September 15, 2023, 01:39:09 PM

Hi guys
Can someone please tell me the tyre size that will fit into the spare tyre carrier. I have 255 x 60 x 15 on the rear and 245s on the front on Rally Rims. Standard hanger bolts on the carrier. I tried the 245s but are too big to close up the carrier. I am thinking 215 x 60 x 15 as a spare. Does this sound about right? Thanks

Title: Re: Spare tyre size for 76C3
Post by: MY081 on September 16, 2023, 04:20:11 PM

The original Spare is 225/70/15 .Hope this helps .Ray .

Title: Re: Spare tyre size for 76C3
Post by: sirfixalot on September 16, 2023, 07:11:08 PM

215 60 15 sounds about what i have in my 78, the bolts on front of carrier can be wound down and i put a couple  of spacers under bracket for rear bolt had to replace the 3/8 bolts with longer ones

Title: Re: Spare tyre size for 76C3
Post by: Philip on September 17, 2023, 09:57:43 AM

Thanks again Geoff.
I think I will use a 215 x 60 as well because it should fit without any problems. Cheers

Title: Re: Spare tyre size for 76C3
Post by: Philip on September 17, 2023, 10:03:51 AM

Thanks Ray

Title: Re: Spare tyre size for 76C3
Post by: sirfixalot on September 19, 2023, 08:09:30 PM

The important consideration is the rolling diameter of the spare wheel has to be equal to the diameter of the rear tyre

Title: Re: Spare tyre size for 76C3
Post by: Philip on September 23, 2023, 08:38:12 AM

Thanks Geoff. Yes I understand the tyre diameter must be he same as the rear to enable the diff to function correctly.

Title: Re: Spare tyre size for 76C3
Post by: Vettech on September 29, 2023, 03:23:11 PM

The spare is a low speed smaller setup as Ray and Geoff indicate.

I'm running OEM Wheels on my 78 - steel rallies, c/w 255's.

These can fit in the spare carrier, since the bolt up bit at the rear can be turned 90° and dropped to a lower position.
AND.
The front two hangers allow the carrier to be lifted, unhooked and also dropped to a lower position.

My STD 255's just fit in, but once the carrier is tightened up, be aware that speed humps are a no go, since clearance now under the rear is very close. (The 255's are a bugger to get into the carrier, esp now I'm old and decrepid.)

Keep in mind that the carrier, cross member, diff/ axle and spare are designed as part of the rear collision crumple zone, and it is highly recommended that the correct spare fully pressurised with air is always in position.

Title: Re: Spare tyre size for 76C3
Post by: Philip on October 01, 2023, 10:41:30 AM

Thanks for your info Vettech Ill take it on board. Cheers