Out of round tyres?

[jimmyjam]

G'day all,
I have a GQ LWB that I recently put 7.50 tyres on split rims. The wheels and tyres are secondhand, but with plenty of tread. I get a horrible vibration at around 70 to 90 kph, and then about 110 it kicks in again, but not as badly.
I've had an alignment, and had them balanced (twice). The guy in the shop reckons I have an out of round tyre, but could not tell me which one...
I've noticed the wheel weights are not completely flush with the rim, could this be the problem?
Any advice would be greatly appreciated!

[MudRunnerTD]

Split Rims can be difficult ot balance and can take allot of weight, Disappointing that the balancer could not even tell you which one was out of round! I have a buckled rim and my man told me which it was and that he put it on the back left side to limit the impact on my ride!!

It might be worth taking it elsewhere and having the tyres taken off the rims and rotated around the rim and reseated for a new balance, could make a huge difference. Then rebalanced and ask the new bloke to show you the out of round on his balance machine, hang around, you want to see it mate.

Hope that helps.

[jimmyjam]

That's what I was thinking, if it takes two attempts for him to balance the tyres, I'm not giving him any more business.

[MudRunnerTD]

yeah i reckon he was just giving you some spin cause he gave up or could not be shagged trying harder. They are a bugger but patience will get a reasonable result.

[jimmyjam]

They wheels and tyres were really cheap, that's why I went with them. I've noticed the ride is a little bit rougher compared to the 235 85 R16 I did have on there, but the little bits of offroading I've done since the new tyres, they seem to grip better.

[Silver]

I bought some new Pirellis a while ago. 750R16 Dakkars. And split rims to suit.

Took ages to establish the tyres were the problem - eventually did so by bolting on a set of extremely worn Hancooks and driving them up to the tyre place. He had to admit that the problem was either his tyres or his rims, changed to another set of rims - still a problem.

Agreed to replace them, made arrangements with, and then sent me to the local Pirelli distributor for the changeover to new ones. They tried to make me go through a process to prove the problem was actually the tyres. After steam stopped coming out of my ears, and polite but assertive language from my mouth, they agreed that all had been that was necessary, and fitted up a new set - which were perfect.

[jimmyjam]

I'm hoping it's a balance issue, as the tyres are second hand...
I did buy a batch of 11, so if I can find which is the dud, I can grab the next best and so on...

[Silver]

some people swear by 'on car' balancing, esp with 750s on splitties.

GQ rims are centred on the hub, not the wheel nuts - you should be able to see the hole in the rim sitting pretty neatly against a turned ridge on the hub

[Finly Owner]

I'm hoping it's a balance issue, as the tyres are second hand...
I did buy a batch of 11, so if I can find which is the dud, I can grab the next best and so on... Where are you?
Have you at least had a careful look at the split beads and made sure they are locked in tight. Don't assume they have. Try to find a truck wheel balancing tyre shop. They have bigger dias to fit the rim centre and accurate machine for "truck" type tyres. I have seen a lot of tyre fitters who think they know how to read a balancer.


Tim

[gec]

When i saw the title "Out of round tires" I thought maybe you were running square ones until you could get some more round ones, ROFL :smileyvault-cute-bi

[jimmyjam]

When i saw the title "Out of round tires" I thought maybe you were running square ones until you could get some more round ones, ROFL :smileyvault-cute-bi
You mean the square tyres could be a problem?! ;)

[jimmyjam]

I'm located just out of Canberra, I'll have a good look at how everything is fitted then probably take it to one of the local 4wd workshops for a rebalance and align.
I only know enough about split rims to know that I don't want to die, so will leave tyre fitting to the pros.

[ilovebeer]

Is the vibration worse when the tyres are cold? I had a set of light truck tyres that would vibrate for about the first 20-30 ks of driving (esp if parked for a number of days) but when they warmed up it wasn't as bad, If I tried to balance these tyres when cold it was hopeless, now days I stick to radials, I suggest getting the tyres warm then having them balanced, see how that goes.

[Finly Owner]

So how did you go with this?



Tim