tyre + rim combo issues

[skips_BIGRED]

i currently own a set of 32x9.5r16 ET's, on 16x7 sunny rims. they are under an 80 series with a 2inch lift...

i didnt realise until after i brought them that they only have a load index of 111 (1090kgs), and the tyre placard on the 80 series specifies a load index of no lower than 114 (1180kgs).

these tyres only get run rarely, for local day trips (ie. the car is never fully loaded, or towing anything- hence, my rational is that the car weighs approx 2.2t, add another 1-1.5t for equipment, passengers etc.. so the net weight on the wheels is no more than 4t)

recently i have run into issues with the beads breaking (at a huge range of pressures from 34psi to 20psi), and waking up the day after to find flat tyres. i understand that this is occasionally happens with four wheel drives, shit/dirt/mud building up to break the bead. however, it is ussually happening to 2-3 tires every time i take them out. (each time i get them re-set it costs me $20-25..)

ok, so i have looked into my options and have decided one of the few options;
1) cut my losses, sell rims and tyres... and start again
2) run tubes (have read of people lowering the pressure too much and ripping the valves off ..etc)
3) buy external beadlocks, and upgrade to a the 36's ET's (which meet load safety index), when these set wear out.

currently i'm leaning towards beadlocks.

thoughts/opinions/alternative suggestions appreciated. cheers

[DAZ]

are the rims and tyres new?

when tyres and rims are new (shinny and slippery) and run at low pressure i have seen the tyre slip off the rim with out much effort. Is this what is happening to you?

Also i have never run wider than an 8" rim with a 12.5" tyre so there is always tyre pressure against the rim.

with your tyre 9.5 wide should maybe you have them fitted on a 6" rim?

Just a though cheers Daz

[skips_BIGRED]

are the rims and tyres new?

when tyres and rims are new (shinny and slippery) and run at low pressure i have seen the tyre slip off the rim with out much effort. Is this what is happening to you?

the tyres weren't new when i brought them (second hand, off ebay). but the rims were new. however, this didnt occur when i lowered the pressure the first few times i took them out. it has only been more recently..

are the rims and tyres new?

Also i have never run wider than an 8" rim with a 12.5" tyre so there is always tyre pressure against the rim.

with your tyre 9.5 wide should maybe you have them fitted on a 6" rim?

the recommended rim on the sidewall was 16x7.5.. but my tyrepower told me to go with a 16x7. These are my first set of 'play' tyres, so really didnt/don't know much about rim widths - so i just went with what he suggested.

i'd loose money selling my current rims, and buying some 6" on a chance it could fix the issue..

i've read that simex's have notoriously bad beads, thats why i was thinking beadlocks..

cheers,
skipper

[-Scott-]

Interesting problem you have, and I'm not sure of the solution, but can offer a few comments.

The Australian Tyre & Rim Association (or whatever they're called) know a little bit about fitting tyres to rims. If they reckon a 9.5" tyre works OK on a 7" wide rim then I wouldn't blame rim width for your problem.

It's not only air pressure that holds the rim to the tyre; there's also a bead on the rim. AFAIK, 4wds are supposed to run "JJ" rims, which means they have "safety beads" (whatever they are) on both sides of the rim. If your rims are "JJ" then this should be stamped/cast somewhere on the rim. Have you had a look?

If you can't find evidence that your rims are "JJ" (and you should find out if JJ rims are a legal requirement in Australia - perhaps PM Ryano?) then I'd go back to Tyrepower and tell them they owe you a refund - for the rims, and all the money you've spent re-seating tyres. That should give you a nice deposit for a better set of rims.

Load rating. Interesting that your tyre placard has higher rating. I'm fairly confident that my brother's 80 series lists 31x10.5" tyres, which have a load rating of 109. Legally, you should be able to run any tyre supplied by Toyota on an 80 series - have you had a look in an owner's manual? If you can find any tyre in there with a load rating 111 or below, you're covered.

Edit: Brother happened to call by in his 'Cruiser. I was wrong. Has two placards on the pillar. One listed 265/75R15 (Yes - 15") with load 112S. (In old money, that size is 31x10.5R15, but I've never seen a 31x10.5 with a load rating above 109 - and that is the size he used to run, until he fitted 265/75R16). There were two other imperial tyre sizes on the other placard, but neither listed a load rating. Interestingly, axle ratings were 1500kg and 1850kg (or something like that). So even with 109 tyres, at 1040kg each, you would need to overload the axles before you overload the tyres.

As an aside, I believe my shorty Paj has axle ratings of 1600kg and 1700kg - combined is only 50kg less than an 80 series. I hadn't expected that.

[alien]

i've never busted a bead on my ETs, but they only have the weight of a sierra to deal with... running them at around 10psi when i first got them i got a ton of crap in the bead, which caused 3 tyres to leak air, one dropped to dead flat overnight... since that happened i chucked tubes in and now regularly air down to 6psi, even some sideways action including donuts couldn't unseat the bead.

my money would be on taking the tyres off, wire brush the inside of the rim around the bead area, clean thoroughly (rim and inside of tyre), fit tubes and try again.

dont forget, 2nd hand tyres have had their beads stretched at least twice before to get on and off the old owners rims, then all the times you've done it has probably "softened" it a bit.

[skips_BIGRED]

It's not only air pressure that holds the rim to the tyre; there's also a bead on the rim. AFAIK, 4wds are supposed to run "JJ" rims, which means they have "safety beads" (whatever they are) on both sides of the rim. If your rims are "JJ" then this should be stamped/cast somewhere on the rim. Have you had a look?

If you can't find evidence that your rims are "JJ" (and you should find out if JJ rims are a legal requirement in Australia - perhaps PM Ryano?) then I'd go back to Tyrepower and tell them they owe you a refund - for the rims, and all the money you've spent re-seating tyres. That should give you a nice deposit for a better set of rims.

thanks for the input scott, had no idea about this 'JJ' notation, had a quick look at the rims just then. can't see any sign of 'JJ', all i can see (stamped) on the inner part of the rim is 'Dynamic - 16x7 - 1200kg' (i thought dynamic was a fairly reasonably brand as far as sunraisers go..). Will have abit more of a look into this tonight.

my money would be on taking the tyres off, wire brush the inside of the rim around the bead area, clean thoroughly (rim and inside of tyre), fit tubes and try again.

i did enquire about a price to give them a good clean up and tubes installed (heavy duty simex ones), and he was asking something like $350-$400.. i also got a rough quote to install beadlocks, and that was around $700. so i figured spend some extra $$ for something that i can use past this set of tyres, to avoid having this sort of an issue in the future..

[alien]

$350-400?!?! wtf!

my tubes cost me $30ea fitted and balanced in 31x10.5r15 - not simex tubes though, but they weighed about 2kg each so they were pretty thick i'd imagine.

[skips_BIGRED]

$350-400?!?! wtf!

my tubes cost me $30ea fitted and balanced in 31x10.5r15 - not simex tubes though, but they weighed about 2kg each so they were pretty thick i'd imagine.

yeah- i thought it was pretty expensive, he wanted $40 labour (each tyre) to give them a good clean up with a wire brush.. 5x 40 = $200

and $30 (each tyre), for the tubes.. 5x30 = $150