Caterpillar Performance Handbook, January 2017, SEBD0351-47

Tire Selection

Tires

Tire LoadWorksheet (Motor Graders)

Tire positions (top view)

Tire #1

Tire #2

Tire #5

RearTandem

Front Axle Forward direction of machine motion

Tire #3

Tire #4

Tire #6

A Machine information: Base operating weight (kg) Rear operating weight (%) Front operating weight (%)

(1a) = (2a) = (3a) =

B Tire loads: Weight on rear tire before attachments (kg) Weight on front tire before attachments (kg)

(1b) = (1a) × (2a) / 4 = (2b) = (1a) × (3a) / 2 =

(Tires # 1, 2, 3, 4)

(Tires # 5, 6)

C Attachment information (reference Caterpillar Price List):

AttachmentType

Tires affected Attachment weight distribution

Ripper

1, 2, 3, 4

25% per tire 50% per tire 62% per tire 40% per tire 5% per tire 34% per tire 55% per tire

Push Block

5, 6 5, 6 5, 6

Front blade (any type) Mid-Mount Scarifier

1, 2, 3, 4

SnowWing

6

3, 4

Attachment weight (kg) (1c) =

Attachment type:

Attachment #1

Tire positions affected (see chart)

Tire #1

Tire #2

Tire #3

Tire #4

Tire #5

Tire #6

Attachment weight distribution per tire (see chart) Attachment weight per tire (kg) = (1c) × (2c)

(2c) = (3c) =

Attachment weight (kg) (4c) =

Attachment type:

Attachment #2

Tire positions affected (see chart)

Tire #1

Tire #2

Tire #3

Tire #4

Tire #5

Tire #6

Attachment weight distribution per tire (see chart) Attachment weight per tire (kg) = (4c) × (5c)

(5c) = (6c) =

Attachment weight (kg) (7c) =

Attachment type:

Attachment #3

Tire positions affected (see chart)

Tire #1

Tire #2

Tire #3

Tire #4

Tire #5

Tire #6

Attachment weight distribution per tire (see chart) Attachment weight per tire (kg) = (7c) × (8c) NOTE: Repeat for additional attachments if needed. D Sum of attachment weights andTotal weight per tire (kg)

(8c) = (9c) =

Tire #1

Tire #2

Tire #3

Tire #4

Tire #5

Tire #6

(1d) = (3c) + (6c) + (9c) = (2d) = (1d) + [(1b) or (2b)] =

E Controlling tire weight = maximum value from (2d)

kg

(1e) =

F Summary – Choose a tire with a rated load capacity equal to or greater than the controlling tire weight =Tire rating > (1f) – Attachments may cause the maximum weight per tire to exceed tire capacity. In these cases the tire supplier should be consulted. – Contact your tire supplier for machine specific inflation pressures to ensure compensation for different tire loads.

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