Full-size Spare in the boot

MX5 Car Clubs of Australia

Moderators: timk, Stu, zombie, Andrew, The American, Lokiel, -alex, miata, StanTheMan, greenMachine, ManiacLachy, Daffy

User avatar
JBT
Speed Racer
Posts: 7946
Joined: Tue Jun 03, 2003 11:00 am
Vehicle: NC
Location: Brisbane

Re: Full-size Spare in the boot

Postby JBT » Fri Sep 07, 2018 3:47 pm

Where will you put the one you take off if the boot is filled with luggage...or not?
Image

User avatar
hks_kansei
Speed Racer
Posts: 6154
Joined: Tue Feb 03, 2009 10:43 am
Vehicle: NB8A
Location: Victoria

Re: Full-size Spare in the boot

Postby hks_kansei » Fri Sep 07, 2018 3:54 pm

To be honest, if you're reducing the diameter of the spare etc you may as well buy a 15inch wheel (195/50/15, or 576mm diam) from an NB8A (or other Mazda, most of them used the same PCD and centre bore, with similar offsets)
It will also be slightly narrower than the 16s, which will give a little more room to move.

You can probably get a 15inch wheel with a tyre on it from the local wrecker for less than the cost of a single new tyre for the 16in spare.


You can calculate the total diameter of a wheel/tyre combo with the following formula:

width*(aspect/100)*2+rim diameter*25.4

for a 195/50/15 it's:
195*(50/100)*2+15*25.4 = 576
1999 Mazda MX5 - 1989 Honda CT110 (for sale) - 1994 Mazda 626 wagon (GF's)

User avatar
Rocky
Concerned Citizen.
Posts: 5914
Joined: Sat Feb 26, 2005 4:42 pm
Vehicle: NB8B
Location: Queensland

Re: Full-size Spare in the boot

Postby Rocky » Fri Sep 07, 2018 7:07 pm

JB - my thought is that the wheel/tyre I have to remove will be flat and therefore easy to get in the boot.
There is actually a reasonable amount of room in the boot if you toss the Space-saver and pack everything in plastic bags.
Obviously there wont be room for my RM Williams boot collection, dinner suit, and cowboy hats.

Kansei, Charcoal suggested the same thing. I just want a matching spare. My cars always have matching spares don'tcha know.
The reason I bought the NB8B as opposed to the NB8A was the wheels. I couldn't give a rats about the dodgey 6 speed gearbox or VVTI. I like the wheels!

I'm too hopeless with Math to do that calculation Kansei - couldn't work out what to do with the numbers. I found a "tyresizecalculator.com" that tells me that the difference between a 195X45X16 and a 205X45X16 is 9mm. I did a quick measure of the OE 16" wheels and then the boot space available and 9mm looks pretty right. Might just sneak in.
Last edited by Rocky on Fri Sep 07, 2018 7:35 pm, edited 1 time in total.
Image
Foundation Member: Grumpy Old Bastards Club.

Mr Morlock
Speed Racer
Posts: 6444
Joined: Mon Feb 04, 2008 11:40 am
Vehicle: NB8B
Location: Melbourne

Re: Full-size Spare in the boot

Postby Mr Morlock » Fri Sep 07, 2018 7:33 pm

Australians are supposed to be resourceful. Mazda provide the space saver for an emergency so the car is drivable. The wheel you take off is almost certainly going to fit in the car hook or by crook- with the boot open or in the passenger seat or strapped on the top etc. If you have driving companions in other car(s)they take it or the "Total care" guy tows it or takes the wheel to an agreed place- the options are many. You also cannot fit a full size wheel in the boot say as a "spare" and get clothes and clobber either. I reckon anyone cruising the countryside needs Total Care which covers towing and accomodation. Now what about the ND- you can barely put a 6 pack in the back of that under done car.

User avatar
Rocky
Concerned Citizen.
Posts: 5914
Joined: Sat Feb 26, 2005 4:42 pm
Vehicle: NB8B
Location: Queensland

Re: Full-size Spare in the boot

Postby Rocky » Fri Sep 07, 2018 7:43 pm

I wouldn't be game to drive it with that piece of 17 yo rubbish on it. Whoever invented it should be tied to it and tossed off the jetty.
No chance "Total Care" is going to work up here in this big brown land, MM.
You would spend most of the day sitting beside the road waiting for a service vehicle that never arrives and the bloke from 'Wolf Creek' who does!
I don't want to be towed or accommodated, I just want to put my full-size spare on and be on my way without delay.
Image
Foundation Member: Grumpy Old Bastards Club.

Mr Sexy
Fast Driver
Posts: 264
Joined: Fri May 11, 2012 7:46 pm
Vehicle: ND - 2
Location: Western Australia

Re: Full-size Spare in the boot

Postby Mr Sexy » Sun Sep 09, 2018 9:36 pm

Munched one of my 17 boat anchors on good sized pot hole a few years ago. Managed to get it in the boot and lid closed with a bunch of cursing and stomping...

User avatar
Rocky
Concerned Citizen.
Posts: 5914
Joined: Sat Feb 26, 2005 4:42 pm
Vehicle: NB8B
Location: Queensland

Re: Full-size Spare in the boot

Postby Rocky » Thu Sep 13, 2018 2:48 pm

I guess the thing that is worrying me about just forcing a full-size wheel into the boot is that it deforms the boot-liner above the boot locking mechanism. What happens if you force it in and shut the boot, and the boot won't open because you have compromised the locking mechanism.
What ever I use, I think it has to clear the 'bulge' over the boot locking mechanism. This inevitably means a smaller total diameter for the wheel/tyre.
I will call in to Bob Jane and see what tyres they have in a 195X45X16. I think this will still be about a cm too big but at least I will have looked at all options that use the OE rim. The only other thing I can think of is to have the tyre partially inflated, say 20 psi and carry a pressure can to bring it up to full inflation.
Image
Foundation Member: Grumpy Old Bastards Club.


Return to “MX5 General Chat”

Who is online

Users browsing this forum: No registered users and 9 guests