We spent a considerable amount of time researching tires and wheels for this build.  There are many brands and sizes of tires and wheels but "Baja proven" tires and wheels are a small subset of those marketed as off-road capable...  While this is not a "race car", it's intended to operate in the same challenging environment and we need our tires and wheels to perform and "survive" everything we throw at them.  We ultimately chose to go with "Method" wheels, a well regarded brand.  As for tires, BFGoodrich Racing has selections that have been "Baja tested" on Trophy Trucks, Class 1's, Class 10's, etc..  We chose to go with BFG KR3's - we expect them to serve us well.  Given the power available and intended use of this car, we elected to go with 35" tires.

"Method" bead-lock wheel

Bead-lock ring

The outer tire "bead" is captured by this ring, allowing us to run the tires at lower pressures for traction/flotation when necessary without worry of "rolling" the tire off the rim.  Typically, a bead-lock wheel doesn't capture both tire beads; the "inside" bead is not captured and seats on the rim like normal but the bead on the "outside" is clamped firmly by the ring.

A soap solution helps ease the initial mounting of the tire

With the bead-lock ring removed, the tire can be easily installed on the wheel by hand.  The lock ring is then installed and the 24 bolts torqued to specifications, securing that bead.  Inflating the tire then "seats" the other (non bead-lock) bead like a normal tire/wheel.

Tire soaped-up and ready to install

We found that lubricating the tire like this then pushing the wheel into it while the tire lays on the floor to be the easiest way to start the mounting process.  Essentially, when you take the lock ring off the wheel, it's the equivalent of removing the entire portion of the wheel that holds the tire's bead on that side.  That makes it fairly easy to get the wheel into the tire.  Then it's just a matter of bolting the lock ring in place to complete the wheel and secure both of the tire's beads.

Tire mounted and ready to go on the car

There are 24 bolts that secure the bead-lock ring - they need to be tightened evenly and torqued to spec. - that took about 40 minutes per tire.  I'm sure someone who does it regularly can better that time but we were trying the be very careful - the tires and wheels represent a significant investment...

Rear tire/wheel on the car

While building the car, we've had temporary tires installed - our 5/1600 car spares.  It's good to finally see the correct tire/wheel combination on the car!

Front tire/wheel installed
 

Aggressive new look!

Removable spare tire mount assembly
There is limited space for a spare tire - we chose to locate it above the engine and behind the fuel cell.    Due to the design of the exhaust system, we elected to mount the spare at an angle rather than flat in order to keep the center of gravity as low as possible.  The entire assembly is removable for easy engine and fuel cell access.

Spare tire mounted
The spare tire is supported and retained securely in the cradle we fabricated; The "stopper" tubes welded to the front support tube help position the tire correctly while at the same time keep the tire from chaffing on the fuel cell.

Filters, spare tire and rear light bar mounted