Wheel balance
- Thread starter FredandJeannesRacer
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bramfrank
BramFrank
Just had my rear replaced at a local dealer.
He has a motorcycle-specific electronic spin balancer from one of the major tire balancer companies. It has a single number and a pair of arrows, so there is no 'which side'.
Took about 30 seconds to spin the wheel and get a reading.
I went from a Pirelli Strada 'E' to the same and the mechanic did not pull the weights - she (yes she) told me that if you have Pirellis and the weight dots are in the same place, 9 times out of 10 you don't need to change them.
He has a motorcycle-specific electronic spin balancer from one of the major tire balancer companies. It has a single number and a pair of arrows, so there is no 'which side'.
Took about 30 seconds to spin the wheel and get a reading.
I went from a Pirelli Strada 'E' to the same and the mechanic did not pull the weights - she (yes she) told me that if you have Pirellis and the weight dots are in the same place, 9 times out of 10 you don't need to change them.
EasyRider
Well-known member
I’m not sure if you mean the old weights from the previous tire were left in place on the wheel when the new tire was put the same wheel. If that is true, the lady who said it was ok is wrong. .No qualified wheel balancer technician would ever do that. All the balancing weights should always be removed from the wheel when installing a new tire on a wheel. The balancer should always start from scratch with a new tire in order to achieve a proper balancing job. Other wise your counter balancing the old weights with new weights plus counterbalancing the new tires heavy spots. You should bring it back and talk to the owner. Leaving the old wieght in place can not be defened at all in any way. The wheel also has heavy spots that are detected by the balancer. Any balancing weight marks on the tire (and I dont think there are any at all) that she talking about dont mater. The tire and wheel have to be done together and from scratch with no old wieght from the old tire.
Last edited by a moderator:
Bustanut joker
Well-known member
Oh yeah we better believe what yer sayin bud!! You the confessed Harley Luver!!!
:lol: All seriousness aside, That woman musta been drunk or the guy that trained her at least. Why the hell ya wanna balance a rim thats already balanced? I've mounted hundreds of tires (and 1.02 wimmen) in my life and never used that technique.
:jester:
3dogs
Well-known member
Here is an article that I wrote for Motorcycle Product News a few years ago about balancing.
A Matter of Balance
By Tracy Martin
<BODY TEXT>
Other than watercraft, all power sports vehicles use wheels and tires to move along the ground making tire replacement and wheel maintenance an important aspect for any service department Wheel balance is not much of an issue on ATV’s or off-road bikes but it is important on street ridden motorcycles. Vibrations associated with imbalance, or wheels out-of-round, are often described by customers as handle bar vibrations at various speeds or wheel wobble and instability in a straight line. Understanding the types of imbalance and how to check for wheels that don’t run true will help you deal with these problems quickly and efficiently.
When a tire is mounted to a wheel you are mating two different components into one. Because the tire and wheel have separate “heavy” spots they must be balanced together. The technical definition of balance is the uniform distribution of mass, or weight, around the axis of rotation—the axle. Centrifugal force exerted on a motorcycle tire traveling at 60 mph can make one ounce of imbalance increase to 22 lbs. The faster the bike is ridden the worse the imbalance becomes and vibration increases accordingly. Tires that are properly balanced on street bikes last longer and provide a smoother ride. Because of their smaller diameter and the rough surfaces they are used on wheels and tires found on ATV’s don’t need to be balanced. Off-road motorcycles often use rim locks to keep tires from spinning on the rim and adding wheel weights is not practical or necessary.
There are two types of wheel imbalance—static and dynamic. Static imbalance occurs when there is a heavy spot located along the centerline of the tire/wheel assembly. During rotation at speed, the wheel tries try come off the ground as the heavy spot rotates upward. This type of imbalance is felt as an up and down motion or vibration. Dynamic imbalance takes place when there is unequal weight on one side of the tire/wheel assembly's centerline. Dynamic imbalance causes the wheel to wobble from side-to-side during rotation. Static and dynamic imbalances are not independent of one another and both can be present in the same wheel.
<GRAPHIC>
“StatDynam Bal.jpg”
Note: To be placed with/next/near to paragraph above.
Caption: Because motorcycle wheels are narrow, dynamic imbalance is less of an issue than on heavier, wider automotive wheels and tires.
<END GRAPHIC>
Because of the width and weight of automotive wheels and tires correcting for dynamic imbalance is a standard procedure. Computerized spin balancers take into account the width of a wheel and can measure static and dynamic imbalance at the same time. Dynamic imbalance can be corrected by placing weights on both outer edges of the wheel. Static imbalance is corrected by positioning these weights along the wheel’s circumference. Motorcycle wheels and tires are narrow, when compared to automobiles, and wheel weights are usually placed along the centerline of the wheel rather than the outer edges. These factors make dynamic imbalance less of a factor and static balancing alone is usually adequate.
I talked to several experienced technicians who have used both spin and static balancers on motorcycle wheels. All of them said that the spin type balancers were faster to use but offered no performance advantage regarding weight placement or accuracy. Most tire changing facilities at racetracks use static balancers and racers, who ride at speeds that are considerably faster than street riders, find that static balance is good enough. The technology used to manufacture production motorcycle tires is so precise that internal imbalances issues are a thing of the past. Cast wheels have been in production for many years and the OEM’s have figured out how to produce them without the imbalance and mechanical problems they had when first introduced.
The most common type of static balancer uses precision bearings on which the wheel’s axel turns. As the wheel and tire are slowly rotated the heavy sections ends up at the bottom. Wheel weights are placed at the top, opposite the heavy spot. Wheel weights come in several forms, stick-on styles that use an adhesive backing, clamp types that are attached to the center of a cast wheel and spoke weights that are placed directly on the spokes. If more than two ounces (56 grams) are needed to balance any wheel, break the tire’s bead and rotate the wheel in relationship to the tire 180 degrees. Repositioning of the wheel and tire should require less weight to bring the assembly into balance. If more than one ounce (28 grams) are required to balance a cast wheel, and stick on weights are being used, divide the weight in half and place them on each side of the wheel’s centerline.
If a customer is having a problem with wheel related vibration, get as much information from them as possible. Does the vibration occur at a specific speeds or is it present all the time. Vibration at all speeds is usually caused by wheels not running true and run-out should be checked. Vibrations that take place a specific speed is usually caused by an out of balance problem. There are two conditions that cause a wheel to not run true. Radial run-out takes place when the wheel is not concentric with the axel causing the wheel to moves up and down with rotation. Lateral run-out is present when the wheel wobbles from side to side. As a general rule .080” (2mm) is the maximum limit for both conditions with .040” (1mm) or less being ideal. Of the two “truing” problems, radial run-out will cause more vibration by a factor of four or more. A quick check can be made with the wheel still attached to the motorcycle using a dial indicator. If a spoke wheel needs to be trued, dismount the tire and place the wheel in a truing stand. If a cast, or mag wheel, has too much run-out it should be replaced.
Having one tool that can both balance and true wheels makes for more efficient use of counter top workspace. K&L’s MC310 Three-In-One Truing Stand balances both spoke and cast wheels using a set of precision bearings. A second set of precision bearings is provided to check fork tubes, crankshafts and axels for straightness. Both sets of bearings are adjustable for height to accommodate axels or crankshafts having more than one size diameter-rotating surface. Adjustable spindles, which locate and center wheel bearings, are provided for building and truing spoke wheels and brake rotors can be checked as well using this setup. The stand will work with a 21” wheel and the width is adjustable to 13 inches at the wheel spindles. Constructed of sturdy aluminum castings the spindles, bearings and hardware are all heavy duty. A dial indicator arm assembly, which attaches to the stand, is available from K&L. A rod that runs the length of the truing stand makes positioning a dial indicator simple and easy to use.
Servicing wheels and tires is a moneymaker for most shops. Don’t get caught up in just mounting and balancing tires. While you’re performing tire service, don’t forget to check brake pads, rotors, wheel bearings and suspension components. You can up-sell service for any of these items and because they are safety related (Can you spell “liability?”) all are important to your shop and its customers.
<END BODY TEXT>
A Matter of Balance
By Tracy Martin
<BODY TEXT>
Other than watercraft, all power sports vehicles use wheels and tires to move along the ground making tire replacement and wheel maintenance an important aspect for any service department Wheel balance is not much of an issue on ATV’s or off-road bikes but it is important on street ridden motorcycles. Vibrations associated with imbalance, or wheels out-of-round, are often described by customers as handle bar vibrations at various speeds or wheel wobble and instability in a straight line. Understanding the types of imbalance and how to check for wheels that don’t run true will help you deal with these problems quickly and efficiently.
When a tire is mounted to a wheel you are mating two different components into one. Because the tire and wheel have separate “heavy” spots they must be balanced together. The technical definition of balance is the uniform distribution of mass, or weight, around the axis of rotation—the axle. Centrifugal force exerted on a motorcycle tire traveling at 60 mph can make one ounce of imbalance increase to 22 lbs. The faster the bike is ridden the worse the imbalance becomes and vibration increases accordingly. Tires that are properly balanced on street bikes last longer and provide a smoother ride. Because of their smaller diameter and the rough surfaces they are used on wheels and tires found on ATV’s don’t need to be balanced. Off-road motorcycles often use rim locks to keep tires from spinning on the rim and adding wheel weights is not practical or necessary.
There are two types of wheel imbalance—static and dynamic. Static imbalance occurs when there is a heavy spot located along the centerline of the tire/wheel assembly. During rotation at speed, the wheel tries try come off the ground as the heavy spot rotates upward. This type of imbalance is felt as an up and down motion or vibration. Dynamic imbalance takes place when there is unequal weight on one side of the tire/wheel assembly's centerline. Dynamic imbalance causes the wheel to wobble from side-to-side during rotation. Static and dynamic imbalances are not independent of one another and both can be present in the same wheel.
<GRAPHIC>
“StatDynam Bal.jpg”
Note: To be placed with/next/near to paragraph above.
Caption: Because motorcycle wheels are narrow, dynamic imbalance is less of an issue than on heavier, wider automotive wheels and tires.
<END GRAPHIC>
Because of the width and weight of automotive wheels and tires correcting for dynamic imbalance is a standard procedure. Computerized spin balancers take into account the width of a wheel and can measure static and dynamic imbalance at the same time. Dynamic imbalance can be corrected by placing weights on both outer edges of the wheel. Static imbalance is corrected by positioning these weights along the wheel’s circumference. Motorcycle wheels and tires are narrow, when compared to automobiles, and wheel weights are usually placed along the centerline of the wheel rather than the outer edges. These factors make dynamic imbalance less of a factor and static balancing alone is usually adequate.
I talked to several experienced technicians who have used both spin and static balancers on motorcycle wheels. All of them said that the spin type balancers were faster to use but offered no performance advantage regarding weight placement or accuracy. Most tire changing facilities at racetracks use static balancers and racers, who ride at speeds that are considerably faster than street riders, find that static balance is good enough. The technology used to manufacture production motorcycle tires is so precise that internal imbalances issues are a thing of the past. Cast wheels have been in production for many years and the OEM’s have figured out how to produce them without the imbalance and mechanical problems they had when first introduced.
The most common type of static balancer uses precision bearings on which the wheel’s axel turns. As the wheel and tire are slowly rotated the heavy sections ends up at the bottom. Wheel weights are placed at the top, opposite the heavy spot. Wheel weights come in several forms, stick-on styles that use an adhesive backing, clamp types that are attached to the center of a cast wheel and spoke weights that are placed directly on the spokes. If more than two ounces (56 grams) are needed to balance any wheel, break the tire’s bead and rotate the wheel in relationship to the tire 180 degrees. Repositioning of the wheel and tire should require less weight to bring the assembly into balance. If more than one ounce (28 grams) are required to balance a cast wheel, and stick on weights are being used, divide the weight in half and place them on each side of the wheel’s centerline.
If a customer is having a problem with wheel related vibration, get as much information from them as possible. Does the vibration occur at a specific speeds or is it present all the time. Vibration at all speeds is usually caused by wheels not running true and run-out should be checked. Vibrations that take place a specific speed is usually caused by an out of balance problem. There are two conditions that cause a wheel to not run true. Radial run-out takes place when the wheel is not concentric with the axel causing the wheel to moves up and down with rotation. Lateral run-out is present when the wheel wobbles from side to side. As a general rule .080” (2mm) is the maximum limit for both conditions with .040” (1mm) or less being ideal. Of the two “truing” problems, radial run-out will cause more vibration by a factor of four or more. A quick check can be made with the wheel still attached to the motorcycle using a dial indicator. If a spoke wheel needs to be trued, dismount the tire and place the wheel in a truing stand. If a cast, or mag wheel, has too much run-out it should be replaced.
Having one tool that can both balance and true wheels makes for more efficient use of counter top workspace. K&L’s MC310 Three-In-One Truing Stand balances both spoke and cast wheels using a set of precision bearings. A second set of precision bearings is provided to check fork tubes, crankshafts and axels for straightness. Both sets of bearings are adjustable for height to accommodate axels or crankshafts having more than one size diameter-rotating surface. Adjustable spindles, which locate and center wheel bearings, are provided for building and truing spoke wheels and brake rotors can be checked as well using this setup. The stand will work with a 21” wheel and the width is adjustable to 13 inches at the wheel spindles. Constructed of sturdy aluminum castings the spindles, bearings and hardware are all heavy duty. A dial indicator arm assembly, which attaches to the stand, is available from K&L. A rod that runs the length of the truing stand makes positioning a dial indicator simple and easy to use.
Servicing wheels and tires is a moneymaker for most shops. Don’t get caught up in just mounting and balancing tires. While you’re performing tire service, don’t forget to check brake pads, rotors, wheel bearings and suspension components. You can up-sell service for any of these items and because they are safety related (Can you spell “liability?”) all are important to your shop and its customers.
<END BODY TEXT>
FredandJeannesRacer
Well-known member
Great article 3dogs! Wow, looks like someone did their homework! Thanks for the info. Fred
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