Hub centic rings/wheels spacers help needed

bigstupidjerk · Post by **bigstupidjerk** » 10 Apr 2010, 00:55

I bought Mazda RX-8 alloy wheels/ tires to fit on my 850 turbo. I tried installing them myself today but failed. I couldn't get the lugs to line up.

Is the guide pin on the hub in the way?
Do I need 5 or 10mm spacers?
Do I need hub centric rings?

The stock for my 850 was 16 x 6.5 with 205/55/16 tires. The new setup is 16 x 7 with 225/55/16. Can I get these to fit or should I start over? Thanks for your advice in advance.

Post by **egads** » 10 Apr 2010, 01:02

Someone jump on me if I am wrong but I think those are 5x114.3 rather than 5x108 wheels so the holes will not line up without an adapter plate which is not ideal.

Post by **egads** » 10 Apr 2010, 02:19

volvospeed.com/vs_forum/index.php/topic/73792-wheel-adapters-from-5x108-to-5x1143-45/

That link has some options for adapters and spacers

zhenya · Post by **zhenya** » 10 Apr 2010, 05:21

Yes, wrong bolt pattern, plus those tires are nearly an inch taller than stock and a cm wider than the 205/55's that already will rub at steering lock. You're going to need to start over.

zhenya · Post by **zhenya** » 10 Apr 2010, 05:41

Went to edit my previous post with more helpful comments but it was too late. Here goes:

When looking for tires and wheels, there are a number of considerations. First, is the bolt pattern - your car uses 5x108. Second is the overall tire size. 205/55-16 is about as big as you can go on these cars without modifications. You can use either larger or smaller rim sizes, but you need to stay within about 5% of that diameter, and not go any wider. You can use this site to compare tire sizes. http://www.miata.net/garage/tirecalc.html

Also to consider is the wheel offset and hub bore. Offset is somewhat flexible, but it determines how far out the wheel sits, so too little offset, and you will rub your fender, too much, and you will rub suspension and/or steering components. The hub bore size on aftermarket wheels is typically adjusted by using hub-centric rings of the correct size. With OEM wheels, you must be more careful, as if it is too small, your only option would be to have the wheels modified. Stock numbers for the 850 appear to be ~42-48mm offset, 66mm hub bore, and ~5.9" backspacing. Offset and backspacing vary somewhat with wheel width, so it's not 100% straight-forward.

bigstupidjerk · Post by **bigstupidjerk** » 10 Apr 2010, 22:52

Thanks, from the link posted, it seems like the retrofit would be a huge headache. And expensive. I jumped on these for $300 for all 4 thinking that 5 lug = 5 lug. Lesson learned. I might be able to sell them at a profit if I have patience.

bigstupidjerk · Post by **bigstupidjerk** » 10 Apr 2010, 23:17

I found EBAY selling 108 to 114.3 adapters for $130 for all 4. They run 1" thick. These RX-8 tires seem like they have a shallow offset. Any way I shake it, are these tires just too big, even with some adapters/spacers? Thanks again.

bigstupidjerk · Post by **bigstupidjerk** » 10 Apr 2010, 23:35

I found out that the Mazda wheels have a 50mm offset. The 850's have a 43mm offset, right? How would a adapter/spacer work?
Does this mean if I add a 25.4mm adapter to a 50mm offset tire that I'd be out of whack?

zhenya · Post by **zhenya** » 11 Apr 2010, 02:46

Adding spacers will reduce the offset, pushing the wheel outwards towards your fender. I think adding a 25mm spacer would effectively reduce your offset on these wheels to 25mm. In any case, there are a couple of problems here - the first is, as I noted above, that these tires are just too tall and too wide in the first place. Even with the correct rim, 225/55's are going to rub badly. The 205/55's that Volvo changed to late in the 850's life already rub, and your tires are another 20mm wider than that. Second, 25mm spacers are really thick. Anything above 10mm, maybe 15mm at the most, and I'd be thinking about replacing my lug nuts with something longer. At 25mm you may not be getting enough thread engagement into the hub to be safe.

Speaking of lug nuts, let me add one more consideration when buying wheels, which is the seat used for the lug nuts. Volvo stock wheels use a 60 degree taper seat that looks something like this \/. This taper seat is fairly common, but many OEM wheels use a ball seat that looks more like a U. Make sure that you are using the right lugs for the type of wheels you end up with.

bigstupidjerk · Post by **bigstupidjerk** » 17 Apr 2010, 16:57

It looks like these will be going on EBAY since no bites locally. I wonder if I could take them to the local Mazda dealer and swap for some tires?