I'm starting down the DIY-automotive path and was reading about how some people use bubble balancers to balance their own tires at home. Can anyone speak to the accuracy of these balancers? Does anyone use them, and if so, how you found them to be precise enough for everyday use?
Long before the spin balancer was invented all tires were balanced by a bubble balancer. If done properly, the 4 point static balance is as good and accurate as any other method.
The most effective bubble balance is accomplished on both inner and outer portions of the tire rim. This is called a 4 point balance, and can be accomplished as fast as any dynamic balance. To statically balance a tire using a bubble, the outer edge locations are determined by centering the bubble with 2 weights at the outer side of the rim. Once the weight is determined these 2 locations are marked on both inner and outer sides then the weight used is divided by 2 and the inner side has half of the weight of the outer side. As an example 2 one ounce weights placed on the outer edge of the tire center the bubble. These 2 locations are marked with chalk, and the bottom of the tire is also marked so when it is turned over the mark will show where to place the weights on the inside of the rim. This creates 4 half ounce weights hammered into position, 2 on the inner rim and 2 on the outer rim.
A bubble balancer is only able to balance the tire in one plane, as if it were a flat disc. A dynamic balancer is able to detect and correct for balance in both that plane as well as the axial dimension. You'll notice that wheels balanced on a dynamic machine often wind up with weights added on both the inside and outside of the rim.
The race team that I buy my tires through (they do periodic group buys), will do free mounting and balancing with a bubble balancer. I've taken advantage of that before and have no complaints. Couldn't tell any bit of difference between a set of tires dynamically balanced and those bubble balanced. The only apparent downside was that it took longer to do the balancing process with the bubble balancer vs. a dynamic balancer.
I grew up in the days of a bubble balancer at most tire shops. The spin balancer was gaining popularity but many older shops still utilized their old balancers. Back then a tire change was about 5 dollars. The method worked well. Today I am in my 40's and have noticed the skill and experience of those days are gone. Go to an auto parts store and the lack of knowledge is very evident also. I have recently set my garage up to do all off my own general maintainence so I bought an older tire machine and bubble balancer. I have done my own tires now for over a year and I drive 500 miles per week on those tires. Bubble balancers are still quite accurate. It is always nice to do for yourself. I have been able to do things on my time frame without paying expensive rates.
I have worked at a shop for over 30 years. And one of the things that people forget about Static balancing is that it gives you the opportunity to rotate the tire on the rim a lot easier than the dynamic machine before filling with air. Rotate the tire on the rim and get the balance as close as possible then fill with air ! Now recheck the balance and finish up with less weight than you would if you did not follow this procedure. This is what I learned thru out the years at various shops gas stations etc... This does take more effort and time but the results could be better. The major reason for dynamic balancing. Saves time ! And is easier to use. Almost fool proof. Nothing wrong with static balancing if you know what to do.
Quite some time ago I was in Dale Earnhardt's pit prior to the start of the Daytona 500. A member of his crew was balancing his tires with a bubble balancer. I asked him why he wasn't using a computerized balancer and he said because they weren't worth crap compared to a bubble balancer. Not much more to say about the subject.
To any one pursuing a comparison. A Dynamic relies on cheap computerized chips that may be failing to read accurately after SO many balance tires. A properly set bubble balancer will always give you a true natural balance that only water can give you. – Just don’t have any beer before using it, otherwise it is on you. :-)