Haven't seen anyone directly compare these two, so figured I'd start a thread as I have now tried both.
Background:
Centramatic and Balance Masters both make similar active wheel balancers that mount sandwiched between the wheel hub and the wheel. They are both constructed from sheet metal and have loose mass inside the ring tube.
Active wheel balancers compensate for out-of-balance tires by redistributing the mass inside the tube to account for the out-of-balance condition. This works because an out-of-balance wheel and tire tends to wobble about its actual center of gravity rather than the wheel's geometric center. The spring-like effect of the pneumatic tire relative to the ground, plus the vehicle suspension provide a restorative acceleration that causes the mass inside the tube to be pushed towards the side of the wheel that has less mass. This effect creates a negative feedback loop that ultimately eliminates the out-of-balance condition, causing the center of gravity of the wheel assembly to assume the geometric center of the wheel.
These balancers work on the same principle as tire beads, but without the mess, plus there is no impact on bead distribution caused by the deformation of the tire at the road surface.
This active balancing method can be used to balance almost any rotating mass that is not rigidly mounted. Balance Masters, for example, also makes balancers for flywheels, airplane propellers, and driveshafts. Rigidly mounted rotating masses cannot be balanced using this method as the mass will actually tend to accumulate on the side with more mass, creating a positive feedback loop that will result in far worse imbalance or possibly even destruction of the assembly. (Also worth noting that these balancers will not correct for an out-of-round tire condition.)
Below about 15-25 mph, the balancers do not provide any balancing action. However, once the speed hits a level at which the centripetal acceleration exceeds that of gravity, the media begins to distribute around the balancer, and the balancer becomes active. Thus, the balance basically resets every time you come up to speed, thereby compensating for any changes in wheel balance, even from temporary conditions like a clump of dirt or ice.
Comparison:
The primary design difference between the Centramatic wheel balancers and the Balance Masters wheel balancers is what they put in the tube. Centramatic balancers use hardened steel shot as the weight plus oil for damping. Balance Masters use liquid mercury. Both claim their method is superior to the other.
Sound:
The centramatics tend to make a bit of noise at low speed since the media is steel shot, but it is fairly minor, akin to the sound made by a slightly rusty brake rotor. The Balance Masters are nearly silent. Both are fully silent above ~15-25 mph.
Fit:
Centramatic - The balancers come as a kit of four balancers. Two are flat, two have a slight dished offset. The variety is intended to give you the maximum chance of being able to fit a kit to both your front and rear wheels without interfering with the brakes. With stock disc brakes and no spacers, the balancers should fit without issue.
Note: with a Super 16 big brake kit, neither Centramatic balancer will fit without a wheel spacer as the pad retainer bracket will interfere with the balancer regardless of orientation. This may also apply to the 17" BBK. Not sure about the regular 15"/16" kits. (If any part of the caliper assembly protrudes past the plane of the hub, odds are it won't fit.) With 1.25" hub-adapter style wheel spacers, either balancer will work on any brake setup in any orientation.
Balance Masters - I first made the mistake of ordering the DR-1500 balancer. This has the correct bolt pattern, but I did not notice a typo on the website regarding the outer diameter, which is 16.25". So obviously they don't fit 16" rims, which I found out the hard way....
The DR-1500 might work with 17" or larger rims. They will probably not fit Super 16" or 17" big brake kits without a wheel spacer, and unknown on regular 15"/16" kits.
Balance Masters then exchanged these for a much smaller model, the JU-5:
These smaller ones will fit 15" and larger rims without any issues.
They are intended to be mounted with the dish facing inwards such that the balancer is roughly in the centerline of the wheel. In a pinch, they can also be mounted facing the opposite way to clear any calipers. (The dished area is sufficiently large that the OEM Moab rims hub surface sits entirely within the dished area with room to spare.) The dished area is also small and deep enough that it will clear a Super 16 big brake kit even without a spacer if mounted in reverse fashion. I'm fairly confident these would probably be able to work with any big brake kit.
Mounted inwards with spacers on a Super 16 big brake kit:
Finish:
The centramatic balancers are galvanized steel, the Balance Masters are black painted. (Not sure if there is galvanization or zinc coating under the paint.) Note the centramatic balancers are very dirty in these photos, mostly due to brake dust.
(The black one in the above photo is the Balance Masters DR-1500.)
Balance Masters JU-5 versus Centramatic. (Note the Centramatic balancer kit includes both dished and non-dished styles. All JU-5 balancers are equivalent.)
To be continued...
Background:
Centramatic and Balance Masters both make similar active wheel balancers that mount sandwiched between the wheel hub and the wheel. They are both constructed from sheet metal and have loose mass inside the ring tube.
Active wheel balancers compensate for out-of-balance tires by redistributing the mass inside the tube to account for the out-of-balance condition. This works because an out-of-balance wheel and tire tends to wobble about its actual center of gravity rather than the wheel's geometric center. The spring-like effect of the pneumatic tire relative to the ground, plus the vehicle suspension provide a restorative acceleration that causes the mass inside the tube to be pushed towards the side of the wheel that has less mass. This effect creates a negative feedback loop that ultimately eliminates the out-of-balance condition, causing the center of gravity of the wheel assembly to assume the geometric center of the wheel.
These balancers work on the same principle as tire beads, but without the mess, plus there is no impact on bead distribution caused by the deformation of the tire at the road surface.
This active balancing method can be used to balance almost any rotating mass that is not rigidly mounted. Balance Masters, for example, also makes balancers for flywheels, airplane propellers, and driveshafts. Rigidly mounted rotating masses cannot be balanced using this method as the mass will actually tend to accumulate on the side with more mass, creating a positive feedback loop that will result in far worse imbalance or possibly even destruction of the assembly. (Also worth noting that these balancers will not correct for an out-of-round tire condition.)
Below about 15-25 mph, the balancers do not provide any balancing action. However, once the speed hits a level at which the centripetal acceleration exceeds that of gravity, the media begins to distribute around the balancer, and the balancer becomes active. Thus, the balance basically resets every time you come up to speed, thereby compensating for any changes in wheel balance, even from temporary conditions like a clump of dirt or ice.
Comparison:
The primary design difference between the Centramatic wheel balancers and the Balance Masters wheel balancers is what they put in the tube. Centramatic balancers use hardened steel shot as the weight plus oil for damping. Balance Masters use liquid mercury. Both claim their method is superior to the other.
Sound:
The centramatics tend to make a bit of noise at low speed since the media is steel shot, but it is fairly minor, akin to the sound made by a slightly rusty brake rotor. The Balance Masters are nearly silent. Both are fully silent above ~15-25 mph.
Fit:
Centramatic - The balancers come as a kit of four balancers. Two are flat, two have a slight dished offset. The variety is intended to give you the maximum chance of being able to fit a kit to both your front and rear wheels without interfering with the brakes. With stock disc brakes and no spacers, the balancers should fit without issue.
Note: with a Super 16 big brake kit, neither Centramatic balancer will fit without a wheel spacer as the pad retainer bracket will interfere with the balancer regardless of orientation. This may also apply to the 17" BBK. Not sure about the regular 15"/16" kits. (If any part of the caliper assembly protrudes past the plane of the hub, odds are it won't fit.) With 1.25" hub-adapter style wheel spacers, either balancer will work on any brake setup in any orientation.
Balance Masters - I first made the mistake of ordering the DR-1500 balancer. This has the correct bolt pattern, but I did not notice a typo on the website regarding the outer diameter, which is 16.25". So obviously they don't fit 16" rims, which I found out the hard way....
The DR-1500 might work with 17" or larger rims. They will probably not fit Super 16" or 17" big brake kits without a wheel spacer, and unknown on regular 15"/16" kits.
Balance Masters then exchanged these for a much smaller model, the JU-5:
These smaller ones will fit 15" and larger rims without any issues.
They are intended to be mounted with the dish facing inwards such that the balancer is roughly in the centerline of the wheel. In a pinch, they can also be mounted facing the opposite way to clear any calipers. (The dished area is sufficiently large that the OEM Moab rims hub surface sits entirely within the dished area with room to spare.) The dished area is also small and deep enough that it will clear a Super 16 big brake kit even without a spacer if mounted in reverse fashion. I'm fairly confident these would probably be able to work with any big brake kit.
Mounted inwards with spacers on a Super 16 big brake kit:
Finish:
The centramatic balancers are galvanized steel, the Balance Masters are black painted. (Not sure if there is galvanization or zinc coating under the paint.) Note the centramatic balancers are very dirty in these photos, mostly due to brake dust.
(The black one in the above photo is the Balance Masters DR-1500.)
Balance Masters JU-5 versus Centramatic. (Note the Centramatic balancer kit includes both dished and non-dished styles. All JU-5 balancers are equivalent.)
To be continued...
