Bare wheels balancing

[Rocnsanman]

And I thought only Commiefornia no longer allows lead balancing weights!

 

[torch]

The best way to balance is not to cut the weight in an attempt to place exactly the right amount in one spot.

Rather, go slightly heavy in total but with two lighter weights and spread them apart on either side of the heavy spot. This distributes the forces more evenly around the rim.

 

[RossKean]

I have never felt the need to use fractional weights. Nice to have a tire balanced properly, but is a single five gram weight going to make any difference?

 

[torch]

I should probably explain that a little better:

EG: a wheel requires 1-1/4 oz of weight at the light spot. Mark the light spot for reference using tire chalk. Use two 3/4 oz weights, spaced, say, 40° apart (ie: 20° on either side of the marked light spot). Temporarily hold the weights in place with a piece of painter's tape. Check the balance.

If the light spot is still the light spot, move the weights closer a bit (eg: 10° on either side of the light spot). If the light spot is now the heavy spot, move them apart a few degrees. Once you find the perfect balance, mark the locations, remove the painter's tape and the backing paper and permanently install the weights.

(Note: make sure the rim is spotlessly clean or your weights may fly off in use. I like to use brake cleaner and a fresh shop towel).

 

[RossKean]

(Note: make sure the rim is spotlessly clean or your weights may fly off in use. I like to use brake cleaner and a fresh shop towel).

Yep. Learned that one the hard way a long time ago. Visibly clean AND degreased.

 

[Mr_Canoehead]

And I thought only Commiefornia no longer allows lead balancing weights!

I've heard that depleted uranium is a good substitute!

 

[08FJRSteve]

In my previous life I worked on aircraft engines and balanced the turbine rotors. In the early days we had to manually calculate the amount of weight to add. In some cases we had to “split” the weight to get the result we were looking for, like Torch described. I put this spreadsheet together with an illustration to help explain it.

 

[Fred W]

Easy cowboy, butt cheeks not clenched. There are some who are unaware if the balancer is not lever it can throw off their wheels.

Ok, I’ll bite. How would the axle being not perfectly level from side to side affect the axial balancing of a wheel? I’m not seeing this as a problem.

 

[Whooshka]

For starters the rolling resistance on both ends will be different because more weight will be on the lower end. The bearings will be cocked on edge and not flush.

 

[Fred W]

For starters the rolling resistance on both ends will be different because more weight will be on the lower end. The bearings will be cocked on edge and not flush.

How does that affect the misbalance around the wheel? The cocked bearings would be cocked the same amount as the wheel is rotated. The heavy spot of the wheel would still find the bottom. Sounds like something ripe for some mythbusting.

 

[Whooshka]

Hey I'm no physicist. LOL Then why do they sell balance gizmos with adjustable legs and built in levels? I'm sure there is a reason for wanting it level.

 

[tschutter]

Hey I'm no physicist. LOL Then why do they sell balance gizmos with adjustable legs and built in levels? I'm sure there is a reason for wanting it level.

That's a really good question - and maybe someone will have the answer, there are a lot of really smart people here.
My take on it is that your balance will be fine as long as you are within a degree or two. You can use any level, one on the device isn't specifically required. Just slap a level on the axel of the balancer and you are good to go. And if you don't have one (remember that houses were built by an carpenters eye for many years), just eyeball it, you will be close enough.
Just my 2¢

 

[torch]

Hey I'm no physicist. LOL Then why do they sell balance gizmos with adjustable legs and built in levels? I'm sure there is a reason for wanting it level.

In theory, there will be an oscillation of the heavy spot if the axle is off-level. In real-world terms it won't matter if it's slightly off. More important to make sure things are straight than level. A slight bend in the axle (or excessive clearance between cones and axle) will have a big effect though.

 

[RossKean]

In theory, there will be an oscillation of the heavy spot if the axle is off-level. In real-world terms it won't matter if it's slightly off. More important to make sure things are straight than level. A slight bend in the axle (or excessive clearance between cones and axle) will have a big effect though.

Agreed. A slope might have some effect if the cones aren't holding the wheel absolutely perpendicular to the shaft (or if, as you say, the shaft is bent). I suppose a slope might place additional lateral pressure on the bearings and create additional resistance to rotation but I wouldn't think a couple of degrees would matter.