Do Semi Slicks Need To Be Balanced?

[DJBarnstar]

So the guy at the local tyre place says that semi's don't need to be balanced.

Sounds odd.

Is this true?

[Duncan]

absolute rubbish.

[DJBarnstar]

Thank you Duncan.

That was my take on it too. I will go somewhere else.

[Victory]

The jury is out on this question.

If the tyres are new then I would balance them no question of if you are going to do a Targa type event with runs that more reflect road driving.

If they are second hand then it depends on the condition that they are in.

I had one used set balanced that were good until the first run which managed to remove a lot of rubber pick up from them and then they caused some vibration. After I removed the weights they were good again.

I now do not balance used semi's as they tend to change a lot with use especially if you swap them around to wear the outer half after the inner half has been worn due to camber angles.

[Duncan]

well yes, I agree they change more than road tyres with usage....but that's no reason not to start with a balanced tyre! it's more an argument to balance them again later if they start to vibrate

[jiffo]

Have any of you blokes experimented with these ceramic beads (inserted via the valve stem) to automatically balance a tyre?

Sounds pretty trick.

Apparently mine dump trucks use big steel balls.

Their tyres tend to tear off massive chunks of rubber and by using the balls the wheel always stays balanced.

http://www.abcbeads.com.au/#!tech-reports/cfcw

[djr81]

The good thing about good tyres is they tend to be good in terms of balance. Same with good rims. I had one fitted last week (just one, budget racing at its best) and no weights were needed- it balanced as fitted. This compared with cheaper road tyres and cheaper rims that need stupid amounts of weights (100 grams and more) to get them close.

But yes you go get a lot of pickup on the track. Its easy enough to remove.

Anyway the point being their start point for balance is a lot better than road tyres. But balance them anyway. Works great until you put a dirty great big flat spot on them.

[hrd-hr30]

Have any of you blokes experimented with these ceramic beads (inserted via the valve stem) to automatically balance a tyre?

Sounds pretty trick.

Apparently mine dump trucks use big steel balls.

Their tyres tend to tear off massive chunks of rubber and by using the balls the wheel always stays balanced.

http://www.abcbeads.com.au/#!tech-reports/cfcw

I use them in my 33" muddies on a Patrol - they have issues with front end shakes and muddies go out of balance from wear pretty quickly. They work great.

But I've never had any issues with regular stick-on balaning for normal road tyres, semis or rally tyres. Waste of money in these applications IMO.

[Marlin]

So the guy at the local tyre place says that semi's don't need to be balanced.

Sounds odd.

Is this true?

Never ever balanced or needed to balance a proper decent quality semi slick such as a Kuhmo, Dunlop, Yokohama etc. There's not much point either, because if you're having a proper crack, they turn slightly on the rim in competition anyway, even with knurled bead rims, so by balancing them you'll actually throw them out of balance in time.

More road based "racey" tyres I do balance, and I've never found one slip around the rim, as they just don't seem to generate enough grip.

[hrd-hr30]

Surely it's not normal for semis to slip on the bead in a road car? Fronts or rears or both?

I've used plenty of lower quality semis like Toyo R888, Federal FZ201, Nitto NT01, and some have taken a fair bit of weight on slightly bent rims - my old Regas on the 180 were a bit fiddy cented... Never noticed any of them going out of balance.

[sav man]

Semi's move a fair bit on the rim. A few years ago they used to mark the rim + tyre, the tyres on our gtr moved about 50mm on the rim

[DJBarnstar]

Well, I have treated myself to a quality set of Hankook z221's. I have not been to the track in almost 2 years and the old RE55's in the shed won't fit the 17"GTR rims I've got now.

Seems there are a few opinions.

I understand R33 GTR rims are forged and should be pretty balanced off the bat?

[hrd-hr30]

Semi's move a fair bit on the rim. A few years ago they used to mark the rim + tyre, the tyres on our gtr moved about 50mm on the rim

are they moving that much every time you track them? Fronts I assume? braking would generate multiple times the linear G of accelleration.

[Marlin]

DJ, the GTR wheels are good, so if they're not stuffed they'll be fine.

I always take note of any slippage, and it can happen either end of the car, though the front is the obvious place it happens most. Obviously the slip is FAR worse if the tyre shop uses lube to get them on, and I always advise the fitter not to use it for that reason. Sometimes it is simply neccesary though to get the tyre mounted.

I do lie. I have balanced wheels/tyres with R comps, but only to balance them after a big flat spot. I screwed one so bad in Targa with the GTS-t (had to get through on one set back then) that we put just under 250 grams on the wheel. It was stuffed lol, and bloody hard to drive!

Edited March 18, 2015 by Marlin

[hrd-hr30]

I'm going to mark mine for future track days and see what happens...

[sav man]

are they moving that much every time you track them? Fronts I assume? braking would generate multiple times the linear G of accelleration.

The fronts went 1 way, rears went the other. The launches of the start line is what for the rears I recon. Big hp rwd classics got heaps more movement on the rim that we got

[r32-25t]

No point balancing race tyres in general as you don't sit at a constant speed for the vibration to come thru the steering wheel

[hrd-hr30]

why do these blokes bother balancing their tyres?

2014 Spa F1 GP:

2013 indian GP:

[Marlin]

Not sure Harry. If you find out let us know.

The guys that know their tyres shift on the wheels will just continue to do what they've always done..... not balance.

[hrd-hr30]

maybe because tyres should be balanced? I notice they also marked it, presumably so they can see if they need to rebalance or remount after a prac/qualy session.

That F1 wheel has 45g on it in that location. Might have more on the other edge. I reckon they'd notice that at 300km/h if it weren't balanced. Most tyre shops will balance to 5g on road cars, because any more than that is noticeable at road speeds even with much greater unsprung mass.

I looked at the wheel/tyre on top of my pile under the house. It had 130g of weight on it. Haven't had problem with it going out of balance. but to be honest, even if it does move a bit, it's going to be better than it would have been with no balance weights. I wouldn't like to start with a wheel that's 130g out of whack. So I think I'll keep doing what I do - balance.

Edited March 27, 2015 by hrd-hr30