There are a few different styles and qualities of balancers on the market these days which can be a bit confusing when you're considering balancing your own tires for the first time. I hear from many riders that just aren't sure which kind of balancer to invest in and if it is even necessary to balance new tires. Here are some points to consider.I'm going to start changing my own tires. Do I really need to balance them as well?
Let's get one thing out of the way, your wheels aren't going to fall off if you don't balance your tires. That is for sure. Back in the "good old days" few repair shops bothered to balance at all. With primitive suspension (if any), vibrating engines, slow road speeds, lousy surfaces and bicycle sized tires it probably wouldn't have made much difference if they had. These days things are a bit different. We are riding at much higher speeds, on much larger tires, on smoother roads with finely balanced engines and sophisticated suspension. The difference in perceived smoothness of a bike with correctly balanced wheels versus a bike that has not had its wheels balanced or, worse yet, one that has been balanced incorrectly can be quite dramatic. Add to that the excessive tire and suspension wear that comes from running unbalanced wheels and eventually balancing starts to sound like a good idea.
But my buddy says he never balances his tires and he's happy. What's up with that?
Just because your buddy's rear end isn't sensitive to tire imbalance doesn't mean his tires and suspension aren't. It's all a matter of degree. This time you might install a tire that just happens to balance up with your rim needing little to no correction. That's great but don't depend on it happening each and every time. The next time you're liable to end up with a combination that will vibrate your eyeballs loose. In any case, many bikes have suspension capable of isolating sufficient imbalance that it never quite gets your attention. In the meantime everything in the system from the tire itself to the shock and fork to the final drive, whether it be chain or shaft, even the swing arm bearings are quite aware that something isn't quite "round." And they're working way harder than they should resulting in excess wear and tear throughout the system. Balancing is such a simple and inexpensive thing to do that it often makes little sense not to do it whenever a tire is changed.
What about all this internal "balancing media" I've heard about?
People have been selling all kinds of "stuff" to put inside your tires that is supposed to "balance" them at speed for years now. There's been all colors of goop and "slime" that are even supposed to seal flats as well. Just don't be around when it comes time to take the old tire off. Yuck, what a mess! Others have hyped glass bead, ball bearings and other "media" of all descriptions. Does it actually work? I don't know, and aside from the claims made by the folks that are selling it, I've never read an actual independent test anywhere verifying that it does. I've been all over the MotoGP pits and haven't seen anyone putting anything but air or nitrogen in their race bike tires. Since this "media" stuff is claimed to work only above 30 mph anyway it would be next to impossible to actually test it since there isn't any equipment to my knowledge that can spin balance a wheel up that fast. In my view more independent testing is certainly needed. You can always find the guy who will buy it, install it and think it's just great. It really depends on how far out of balance his tire was to start with and how sensitive he is to detecting imbalance. Besides, we often assume that whatever we spend money on was money smartly spent. Right? Human nature at work I guess.
One major independent industry publication, Motorcycle Consumer News®, who is known for it's lack of paid advertising and subsequent impartiality tested one of these products in the October 2006 issue. Their editor's take on the particular "media" they tested was that the tire, "felt heavier, with a stronger sense of gyro stability, but was noticeably less smooth running than when factory balanced, but perhaps just slightly better than with the original weights removed." Stronger sense of gyro stability? I'm always looking for my bike to turn easier and faster so the one thing I'm not looking for is more gyro stability! They ended with a simple, "Our advice: Go for a proper spin balance when you buy tires; it's more effective."
What kind of balancer do I need?
There are basically three different types of balancers: Dynamic or "spin" balancers, static balancers and bubble balancers.
You'll most likely find a spin balancer in your dealer's workshop. The benefits to a shop in having a spin balancer are:
Speed. A wheel can be balanced in a minute or two.
Simplicity. As with most automated equipment, spin balancers are pretty "stupid proof." With less input there is less chance the operator will screw up the job.
On the other hand there are some downsides such as:
Maintenance and Calibration. Automated equipment is great when its cared for. A lack of care ends up with a poorly calibrated machine that will cause more harm than good.
Expensive machines often stay in use well beyond their service life giving poor results.
Adaptability. Can the machine be set up to do all the different varieties of wheels in the marketplace? Usually not. When it is possible, does the operator know which mountings to use, etc?
Bubble balancers are not anywhere near as accurate as either a spin or static balancer. Their main advantage is that they're cheap. If you are going to use a bubble balancer I would almost recommend not balancing at all. In my experience they are totally ineffective.
For the small shop and home user the simplest and most durable balancer will undoubtedly be a static balancer. For that matter, the next time you're at the Superbike or MotoGP races take a stroll through the pits. Here are teams that can afford the best and what will you find? Static balancers. I've yet to see a spin balancer in any of the top team pits. And these guys are running close to 200 mph.
What style of static balancer will work best for me?
Static balancers haven't changed much in design over the years. They basically consist of a frame of one kind or another with a pair of bearings at each end supporting an axle. The wheel is either supported on the axle by cones or adapters or just left to sit on the axle as is.
My balancer as pictured above is a departure from the normal style. Since I had space saving and light weight as part of my objective, I designed a balancer that needs no included stand. The user supplies two supports of equal height such as chairs, jack stands, cinder blocks or what-have-you.
What are the technical considerations when comparing balancers?
Ok, now we get down to the nitty-gritty.
Size. As they say, "size matters." Consider how often you're going to use the balancer as well as where you're going to store it for the majority of time when it isn't being used. If you're like me, garage space is always at a premium.
Weight and Portability. Are you looking for a balancer that is going to stay in your garage or would you like one with the option to easily take it with you for those "tire changing marathons" at your buddy's place?
Adaptability. This is a big one! Does the manufacturer offer different mountings for all the different wheels you might run into today and in the future or will you have to buy special adapters from the dealer? I can't stress how important of a consideration this should be. A balancer will do you no good if it won't work on the wheels of the bike you'll be riding next season. Think ahead and ask the question before you buy.
Bearings. One critical aspect of a balancer that affects its performance are the type and quality of the bearings used to support the axle. They should be of a low drag design but also protected from the elements. Many balancers use exposed ball bearings. These have very low drag but if you can touch the balls then dirt and grit can too. On the other hand, sealed bearings like those in your wheels, are designed with rubber wipers in order to protect the bearing from water and dirt. They stay clean inside but the wipers produce drag and stiction which are the last things you want in a balancer. I am using shielded bearings. This style uses steel covers on the sides of the bearings which protect them from dirt and grit but do not produce any drag. A perfect combination.
Axle. Often overlooked, the axle is also a critical element in the balancer. It must be perfectly round, straight, hard and resistant to bending. I chose my axle source very carefully. I ended up with .500" tool steel. It is dead-on-size and straight within .001" over its 12" length.
Cones. In order to support the wheel without any runout or wobble, cones and adapters must be machined to exacting specifications. Their surface has to be dead-on-size and perfectly concentric with the axle bore. If this isn't done correctly you'll be balancing to compensate for the runout in the cones rather than the imbalance in your wheel. I machine my cones and adapters on a CNC lathe producing both the taper and bore at the same time in one setup. What this means is that the axle bore and surface are dead-on. You should also consider the material the cones are made of. The material should be durable. Plastic cones will not last and probably will not hold their size. Look for steel or aluminum. Mine are machined from 6061-T6 aluminum billet.
I hope I have given you at least a little bit of information here to help you make the right purchase. Whether you purchase my balancer or a competitor's I am confident you will derive a lot of satisfaction balancing your own wheels and tires and, in particular, knowing the job has been done right. If I can be of any help please email firstname.lastname@example.org or give me a call at (714) 842-9210.