Are OEM Wheels Marked with a "Heavy" Spot?

[Bob K.]

It's tire replacement and balancing time. Last time, I just aligned the red dot on the tire with the valve stem on the wheel. This time, I want to make sure I really know where the heavy spot is on the wheel. I plan to throw the wheel alone on the balancer and see where the true heavy spot is. However, just for my edification, does anyone know if Yamaha marked our wheels with "heavy spot" markings? Here are a couple potential "heavy spot" markings on the front wheel.

 

This "H" is on the side of the wheel. It seems unlikely this would be the "heavy" spot, because why would the wheel manufacturer add extra raised metal to this spot just to mark it as the "H" heavy spot?

 

This spot, which looks like a stamped Japanese symbol of some sort, is inside the wheel.

 

I didn't see any other marks on the outside or the inside that could be construed as "heavy spot" marks.

Edited August 30, 2018 by Bob K.

[skydoc_17]

Hey Bob,

You have posed some interesting questions. I will attempt to share with you what I know about this subject. The "H" that is cast into the outside of the wheel in your first pic is the dept. the wheel was cast in. If more than one mold was used to cast this rim in dept H, then there would be a stamped number in the area before the H. (ie: 1H, 2H, etc.)

Because our rims are cast in a mold and then C.N.C. machined, my guess would be that the mark you are seeing in pic #2 is the production stamp of the operator that machined your rim.

The industry standard for marking a rim is actually a single punch mark on the surface facing outward, and the dimple indicates the "LIGHTEST" area of mass on the rim.

Now, about the tires. You will usually find one or two colored dots on a modern motorcycle tire. The RED dot denotes where the "belts" or "Plys" overlap, and this dot shows the heavy side of the tire. You could also see a YELLOW dot on the tire, and this dot shows the lightest side of the tire.

Because I mount and balance my own tires, I personally would not hesitate to debead and shift a tire on a rim to decrease the amount of weight that is needed to balance a tire/rim. I have found that dimples on the rims and colored marks on the tires are nothing more than a general reference, and depend highly on the precision of the operator inspecting the rim or tire. Not a bad place to start, but certainly not the final word on tire and rim balancing.

For those of you that don't enjoy the availability of tire and rim mounting and balancing, I personally have had a dealer remove, debead, and shift a tire on a rim if I found a small boat anchor attached to one side of my rims due to the mechanic not taking the time to shift a tire to find the best match between tire and rim. Don't be afraid to speak up when picking up your dealer mounted tire/rim purchases if you notice excessive wheel weights on a rim.

Hope this helps,

Earl

[Bob K.]

I checked both wheels on my Harbor Freight motorcycle tire balancer and the heavy point for both is about 5 inches to one side of the valve stem. The heavy spots don't coincide with any marks.

 

I got an email from Shinko customer service today. They indicated the red dot on the SR777 tire should be aligned with the valve stem, though they did not overtly indicate that the red dot was the tire's heavy spot or light spot. Proceeding from the belief that the red dot is the tire's light spot, I aligned the red dot with the heavy spot on the wheel. I still required 1oz of weights almost directly opposite the wheel's heavy spot in order to balance the tire.

Edited September 4, 2018 by Bob K.

[skydoc_17]

Hey Bob,

I am sure that your rim/tire has been reinstalled on your bike by now, so these next comments are for "next time". I feel that one ounce of wheel weights is enough to debead and rotate the tire on the rim. I would have placed the red dot exactly opposite of the "heavy spot" you found when you balanced the rim without the tire. I would also admit that my OCD makes me strive for a level of perfection not enjoyed by most people. (just ask my wife!) I would like to commend you for having the courage to do this vital maintenance to your bike yourself. I always have a great sense of pride when I work on my bike because many times I have not been impressed with the quality of service or the cost for that matter at many dealers.

Good job Bob, and thanks for posting your results to the forum.

Earl

[Bob K.]

Are you proceeding from the belief that the red dot indicates the heavy spot?

[skydoc_17]

Hey Bob,

I am. But lets take a look at the tire you just mounted. Where was the weight mounted on the tire you just balanced? Was it on the same side of the rim as the valve stem and "red dot", or was it on the other side, or somewhere else?

As I said earlier, placement of the dots, and marks on the rim are not nearly as important as the proper balance of the tire with as little weight as possible, in my opinion. I am mildly curious weather you added the ounce of weight to counterbalance the valve stem and red dot, (in this case a debead and tire rotation would be in order) or did you need to add even more weight to the same side of the rim as the valve stem. Either way, if the tire is balanced, and the bike rides smooth, then you did just fine, and I commend you!

Earl

[Bob K.]

To balance the tire, I aligned the Shinko tire's "light spot" red dot with the bare wheel's heavy spot. I did this because of Shinko customer service saying I should align the red dot with the valve stem. While this would seem to indicate the red dot is the tire's light spot, customer service would not directly tell me what the red dot signifies. I still had to add the ounce of weight about opposite the bare wheel's heavy spot.

 

 

It's crazy: I spent an hour with the Googles and no one can get their stories straight when it comes to tire dots. Yellow is supposed to be the light spot. Red is supposed to be the spot of maximum radial runout (the "high" spot on the tire). Most say align the dot--red or yellow--with the valve stem but they make the (incorrect) assumption that the valve stem is the heaviest spot on a wheel. Further, by saying the red dot always takes precedence and should be aligned with the valve stem, they all seem to be conflating radial runout with weight.

 

If a high spot (red dot location) on the tire is co-located with the heavy spot on the tire, then you'd have the downward pressure of a tire bulge combined with the extra centripetal force of the heavy spot on the wheel. That might make the tire have more downward pressure at that location, which would require more weight opposite that point to balance out the bounce. Keep in mind my tire is gravity balanced, not spin balanced, so radial runout in itself is irrelevant...unless the maximum radial runout spot also happens to be the heavy spot because of the tire being thicker in that location. But then why would Shinko tell me to align the red dot--a potential heavy spot--with the valve stem??

 

It makes me grumpy that tire companies and internet users are imprecise and all over the map in this discussion.

 

At any rate, thanks for the ideas, Earl.

Edited September 11, 2018 by Bob K.

[Venturous Randy]

I have mounted and balanced a lot of tires that I have put on my 83 in 150K miles. The only thing I can say is almost always the weight stayed in about the same spot on the wheel, no matter what markings may be on the tire. To me, it appeared more weight issues were with the wheel, rather than the tire.

Randy

[YamahaLarry]

Pretty sure that most a alloy wheel manufacturers balance the wheels. They are pretty much balanced before the final high speed machining in the lathe. But I have noticed drilled dimples in alloy wheels and have been told that it was weight removed to balance the wheel.

 

Most of the time, I mount and balance (no beads for me) my own tires and have always aligned the tire dot with valve stem. And there is an obvious weight difference when using a standard short stem or maybe a stainless 90 degree stem.