AKennedy87

I have a 87 Runner with stock 15X7 Rims and the 225/75/15 tires. Just reciently i got a permit to go on cape cod national seashore which has some fun sand trails on it. I would like to upgrade my tire size to 31X10.5's but keep the stock rim. If i am dropping down to anywhere from 9-16 psi and doing casual driving in the sand should this be an okay size, will I bust a bead or will any other problems occur?
Thanks,
Alex

ayoung101

i've got an 89 with 31x10.5 BFG AT's. i haven't been yet on the dunes by me, but everyone i've talked to said i won't have a problem. i went with my buddy who has 31x10.5 BFG radials (much lower grade for offroading, moreso for road travel) on his zr2 blazer last summer and he had no problem. so i can't imagine you'll have any problems either. but i HIGHLY recommend at LEAST upgrading past the radials. his wheels just look like they're tiny little wussy tires when sitting next to mine. he wants to upgrade from his tires as well.

by the way, i see by your # of posts that you're new to the club. welcome! this club is awesome! make sure you post pics of your truck!

AKennedy87

Yea i want either AT's or MT's

ayoung101

you're good to go then! if the radials can do it without a prob, then the AT's or MT's won't have a problem!

SoCal4Running

I run about 8psi in the sand and have not ever lost a bead while crusing around. If your jumping or turning sharp at speed ect all bets are off.

Tires that are newly mounted on rims tend to de-bead easier too so take that into consideration when you air down if they are new.

Scofco

Never heard that before, any idea why?

Lucky

I used to do quite a bit of sand off roading in the Middle East when I lived there (UAE). In my experience you don't want too aggresive a pattern - ATs would be better than MTs.

You also need to keep the momentum up - You need to drive a lot faster than when running in Mud or over rocks. All depends on the consistency of the Sand though. Sand can build into a crust like snow if it gets a consistent level of just enough wind. If you run over this at any speed you can ride the crust, but if you stop then you will sink most surely. Also MTs when stuck will dig you deeper better than any shovel will.

If you are going up a dune and get stuck, roll back early rather than plugging on, you should be able to ride out of the ruts easy and then take a decent run up so that the momentum is good.

Also whatever you do don't turn the wheels on a slope, you will dig one corner in and flip the motor easy as pie.

Cheers and have Fun

toy283

I don't think that '87's came with 15×7" rims, only 15×6". If they are 7", 31's will fit just fine (it's what Toyota used for stock 31" tires). If they're 6" rims, they may be a little narrow but will hold the bead that much better. Also, for sand, an overly aggressive mud tread can be bad juju. They tend to dig big holes and get you stuck. For sand, wider and less aggressive treads are usually best.

toy283

Newly mounted tires haven't "stuck" to the rim yet. The tire lube used for mounting is some seriously slimy stuff. Once it dries up though it acts sorta like glue and helps the seal. Until then then slickness that helped the tire onto the rim can help it off as well.

Lucky

I used to use Bridgestone Desert Dueller on my Cherokee in the UAE. Can't remember the size but they were stock size on a 4L limited auto Cherokee (1995).

They were excellent in the sand, pretty much road biased tread pattern (think they are a 80% on road tyre, aired down a little (about 22psi) they were good and didn't dig holes like a MT would do.

The wider the better tends to be the rule. If you can fit big balloon tyres on if you have the wheels for it (and the clearance) a 31x11.5 would be ace.

Cheers

AKennedy87

Yea, my 4runner has the stock rims and they are 15x7. Its an 87 sr5 4runner with 225/75/15 tires on it now.

toy283

I remember those rims now. I traded a set for a transfer case once since they wouldn't fit my solid axle truck. The aluminum rims available on SR5 packages starting in '86 or '87 were 15×7". My mistake.

L33T35T 4Runner

i run 31 10.5 r15s on my stock toy rims. i think my rims are 7.5s... not sure

either way.. i run 2wd, so i'll drop the tire pressure to 6 in the front and 4, yes FOUR, in the rear. i'll go anywhere the 4x4s will

havent lost a bead yet... just take it easy on the turns. you dont need to go down past 10 PSI, unless you're really stuck, take it down to 4 psi

toy283

Four's not too bad. I run 2-3psi for wheeling all the time

AKennedy87

Thats cool man, i forgve you.
It was my first time in the sand and I went down to 18ish due to the great advise from my dad... it didnt feel good so the later that day i went at 13-14 psi. I was told later that it still was kinda high, the National Park Service people said to run at 11 but i wasnt too sure. I also like to have room to work with, incase i do get stuck i can just keep dropping it down ya know, but next time with the current tires i have, i will go atleast 11. Thanks

RedRunner_87

I had the same rims on mine. I hated them, made the tires to skinny.

toy283

15×7's make 225's too skinny? Until the 15×7 aluminums came out, 225's were mounted on 15×6 rims. My 4Runner is this way. They seem just about right to me.

RedRunner_87

I had 31x10.5, I thought they looked skinny on my rig. They look so much better with 15x8 on it.