So I have been driving around for awhile with a Racing Brake F/R BBK on my FD, but these brakes won't clear the OEM 16" spare tire (I tried it...even the rear won't clear) Since the RX8 comes with a 17" spare tire as an option I thought it would be worthwhile to pick one up and put it to the test.

The results are better than my expectation - the RX8 spare wheel will clear both the front and rear brakes. Really all I was hoping for was to be able to mount it on the rear, and if needed swap tires rear to front in a pinch if I had a front blowout. But the RX8 wheel easily clears both ends. It also fits nicely in the spare tire well, although it may stand proud a few mm higher than the OEM 16" spare. A small price to pay for the peace of mind that if I have a blowout, I can actually fit a spare tire to my car and at least limp home or to a tire shop. I highly recommend this mod if you have a BBK front and rear.

Here are a few pics of the fitment


First, the rear axle:





Tons of clearance:




Front, again no problem with caliper clearance:





This may be common knowledge already, but I did not find anything in a search so I thought I'd post my results.

 

Legit, thanks for posting

Do you have the standard RB front BBK or the 'inboard' setup?

 

The setup was on the car when I bought it, I think it has the standard RB calipers.

 

Evidently many/most RX-8s came with the can of aerosol glop and no spare--- the spare was an option, and a pricey one at that. These aren't as easy to come by as I had originally thought.

 

that is correct, the Rx8 came with a can of fix a flat. the spare tire came in a kit, which was $$ and useless. perhaps there is another mazda with a 17" spare, the 6 has the same 5x114 bolt pattern

 

The spare tire was an accessory option, there are always people selling the complete kit on eBay or whatever but that has a lot of unneeded parts like the mounting frame etc. I found that there are sellers of just the rim and tire that were coming up from time to time in the $200 range on eBay, I located mine from a Nor Cal RX8 owner who was selling the wheel setup plus the cover bag on craigslist as he was converting his RX8 for track duty. Picked it up for $170 shipped, which is a premium over a comparable FD spare for sure. But it was brand new, and priceless to have on hand when you have that flat tire IMO.

Good idea about looking for a different Mazda with a 17" spare though!

 

I think the Mazdaspeed 3 uses the same spare tire.

 

i just looked a bit, and i think you're correct. it lists a 17" spare, for the 2300cc engine, which i think is the Mazdaspeed only? also the 14 and 15 6's have a 17" spare option. the miata had a fix a flat kit, like the Rx8.

i should maybe add that a 17" spare wheel in a 5x114 bolt pattern shouldn't be too hard to find, outside of Mazda.

if it matters the stock spare is 16x4 with a 40 offset

 

The later model fd came with a 17" spare. I have a couple for those interested =D

 

What size tire came on it?

 

man... i couldnt tell you off the top of my head. i will check for you tomorrow after work...

 

price ?

 

i need to find out how much they are to ship first. with a tire on it, its kind of heavy. could be expensive....

 

got some pictures and stuff of the spares i have

 

I have an 8 spare as well. I tested it with my stoptechs and it clears. The best part is the 8 owners sell these for cheap.

 

Looks to be the exact same rim and tire as my RX8 spare.

 

Do these fit in the spare tire well still?

 

Yes, with some room to spare. The only change point is that the wheel center seems to protrude slightly above the body trunk sheetmetal - so the spare tire cover floats a bit above the surrounding trunk area. But you really can't tell once the rear carpet is back in place. That is the only negative to this change.

I'll shoot a picture of it fitted to the spare tire well and post it later.

 

Here's a couple of shots of the tire well area with the RX8 spare:

 

Thanks for sharing, this has always been a concern for me since I move up to 17" wheels. Time to search for some junk RX-8 in the area.

 

Seems like RX8 spare tires are going for $200 now and shipping from Japan for a 17inch FD spare is an arm and a leg.

I ended up getting a spare from a 2019 Mustang for $40.

It's the same diameter as the stock spare 125/70R17 and fits in the spare tire well in the FD.

Another option for people with BBKs.

 

That's great information. Thanks for sharing.