Balancing wheels

[p.mole1]

How hard can it be! I have just had my 14 inch wheels powder coated, nice job. Had new 14 inch Toyo 888 tyres fitted but I have never seen as many weights stuck on the inside of a pair of wheels. Are Toyo tyres poor quality? I have weights stuck upon weights. I have fitted the wheels and they seem ok but I have a ridiculous amount of metal stuck on. I usually only require the odd few weights.

[Jonathan Kay]

There's an interesting discussion about this somewhere in the archives, including how tyres are sometimes marked with coloured spots to show the mass distribution.

Edited: Mentioned here. But there's also a longer discussion somewhere.

And IIRC reports of better rebalancing reducing the number of weights.

Jonathan

[SM25T]

Yellow dot next to valve. If no yellow dot, red dot opposite valve (180°). It may be a rim is bent if a lot of weights needed. You can't successfully balance at 18psi ... need to inflate to maybe 30psi for balancing, then reduce it after.

[ScottR400D]

I always balance my wheels and any of my club member mates’ wheels at 18psi or so, never had an issue and don’t see why you would, to be honest. 

Its true that a distorted rim could end up with a lot of weight on it, be balanced and yet may well still cause vibration. 

Having said that, fitted a pair of ZZS for a mate last week, on a 270 and one of them needed what I thought was a lot of weight, 80g close to the spokes and 40 on the inner edge. We couldn’t see any damage and it ran true enough. The rim had a similar amount of weight on it before so it seemed to be the rim, not the tyres.  

I use a shift plane programme which always gives a round number (10, 15, 20 etc) and adjusts the position of the weight laterally and radially to give a good balance and minimise the size needed. It’s almost always 0-0 on the second spin. This should be possible on any rim I’ve ever seen on a 7. 

[SM25T]

I had a tyre depot try to balance 7 wheels at 18psi and they were constantly adding weights all over the place. The tyre was flexing, or maybe turning on the rim ? Upped the pressure to 30psi, removed all the weights and started again. Succeeded with very few weights.

[ScottR400D]

It’s possible I guess but I’ve not seen a balancer that spins fast enough or starts/stops fast enough to cause a tyre to move on the rim.

If the assembly’s not properly clamped it can turn on the shaft but my balancer, like most, will sense that and throw an error. 

 

[p.mole1]

Thanks, one of wheels has 200 grammes on it! also the yellow dot is 180 degrees out. I will try and find someone who knows what they are doing

[SM25T]

A lot of young fitters say dots don't matter any more. Probably means they don't teach it at tyre fitting school any more. It does make a big difference. When I got them to turn the tyre and line up the dot like I asked, they were surprised how few weights were needed !

[ScottR400D]

I think the reason they often don’t matter is because tyres are better made than they used to be so they’re less imbalanced. 

I think a lot of this is to do with the fact that most OE wheel/tyre assemblies are put together by outside suppliers and supplied to the production line in sets. 

As is usually the case, margins are fine and the assemblers won’t waste time messing about with difficult to balance tyres and will reject. Together with OE limits on maximum weight size (60g IIRC) the tyre manufacturers have had to improve and have shorter ply overlaps etc. 

I guess there are still plenty with significant imbalances and they’ll likely end up in the aftermarket so lining the dots isn’t a bad idea but fitters will only bother with a difficult to balance tyre. 

[ScottR400D]

Just swapped two set of tyres to different rims today. All ZZRs onto a set of CC wheels and a set of Barnby split rims. 

Biggest weight used was a 60g, all balanced first time at 18psi. 

Btw ZZRs don’t have yellow/red dots! I have a new set waiting to go on my own car.