Retread and Repair Recommendations
Contents
1. 1 4 6 9 11 14 15 17 18 Over MNAO 19 37 39 3 Over LO ea 40 41 OY 59 60 01 and Delivery E 54 55 57 11655111 acta Inside Cover 5 10 11 19 20 23 24 26 31 34 36 42 44 47 54 58 61 64 73 74 77 78 11655001 Inside Cover 5 39 41 Pressure ge 5 20 38 39 64 116551116 1011110113 01010110100000 11 19 20 Pressure SENSO 0 001001010101010 19 46 2 Pressure Cold Inflation 10 19 38 39 40 44 E ER Introduction 19 45 47 49 57 58 73 Air 1 008 Inside Cover 22 34 40 59 4 2 12 18 24 36 6678 Recreational Vehicle es 21 10 21 54 66 VICE 0 392 533 Intro 24 34 35 40 43 53 55 57 58 Repair Bead 53 58 Repair Inner 53 58 1163117 Nail Hole Intro 53 57 Repair Section E EE 53 97 Repair Spot REDA 0000 57 61 Intro 2 24 30 50 51 53 54 58 66 Retro t 0000 1 2 6 15 16 18 0000001010000 23 4 59 62 63 5 Rotate Rotation Inside Cover 45 6 DN O A A T 1 2 10 18 44 73 74 d E E 23 24 26 40 42 65 Runout Radial 1 23 30 47 49 Seege 19 24 26 31 33 432. X ONE RETREAD AND REPAIR RECOMMENDATIONS 54 Retread Limits Casing Age Limits Initial Inspection Shearography Buffing iy GENERAL REPAIR GUIDELINES 55 56 Skiving REPAIR LIMIT SPECIFICATIONS 57 58 Nail Hole Repairs Section Repairs Spot Repairs X One XZU S Tire Repair Recommendations Bead Repairs Inner Liner Repairs Builder Enveloping Curing Final Inspection E 0 MICHELIN A better way forward CS 54 There are no unusual or special procedures necessary for any modern retread plant in North America to handle the X One casings There are however some equipment changes that may be required to handle the wider tread and casing widths The information described in this technical guide is the most up to date at the time of this publication However the X One product and casings continue to evolve As new products arrive and are enhanced updates to this guide may be needed RETREAD LIMITS e Line haul greater than 150 000 miles per tread life 1 retread e Regional and P amp D 75 000 to 150 000 miles per tread life 2 retreads e Severe Service On Off Road Urban Refuse less than 75 000 miles per tread life multiple retreads CASING AGE LIMITS Customer or tire manufacturer specifications may have more stringent shorter life requirements that must also be met For Line Haul 7 years For Pickup
3. or See Note 100 mm 30 mm below or 9 130 mm 20 150 mm 1 cable L Length in radial direction W Length in circumferential direction Note Limit for Severe Use represents total of section and hole repairs for both crown and sidewall combined Refer to radial repair chart to select proper size of repair unit 57 58 BEAD REPAIRS RUBBER ONLY DAMAGES MINIMUM DISTANCE BETWEEN REPAIRS QUANTITY W ALL APPLICATIONS 8 per tire RUBBER ONLY DAMAGES EXEMPT FROM REPAIR MINIMUM DISTANCE BETWEEN DAMAGES LOCATION Lx APPLICATION BEAD TOE no damage to bead seat no damage to chafer 2mm x 50 mm 75 SEVERE USE CHAFER STRIP DAMAGES MINIMUM DISTANCE BETWEEN REPAIRS QUANTITY Lx W ALL APPLICATIONS 8 per tire L Length in radial direction W Length in circumferential direction NOTE No repairs to BODY PLY are permitted inside or outside of the tire in the area within a radial direction of 75 mm from the bead point See area ABA INNER LINER REPAIRS Blisters which are burst must be repaired For blisters that are intact Height depth of blister greater than 5mm must be repaired e Height depth of blister less than 5 mm should be left intact and not repaired if no single blister has an area greater than 30 000 mm 45 in2 the total area of the blisters is not greater than 60 000 mm 90 in2 If the size of the blisters is above these l
4. 200 100 Duals Michelin X One Tire WHEEL TEMPERATURE X ONE TIRES vs DUALS 220 200 180 160 degrees F 140 120 100 80 Source Recent evaluations at a Michelin facility in South Carolina Thermal Imaging The thermal image photos were captured after the repeated stopping test followed by 30 minutes of driving without braking A brake drum temperature advantage for the X One tire of 90 degrees F was still apparent even after the cool down period It is safe to say that for any given truck brake Duals Source Recent evaluations at a Michelin facility in South Carolina temperatures on X One tire equipped vehicles will be significantly cooler than brakes on trucks running conventional duals This effect will be most pronounced during periods of heavy braking but will persist for some time after braking has ended X One tires 69 ISO LOAD INDEX AND SPEED SYMBOL 72 DEFINITIONS 73 74 SPECIAL TOOLS MOUNTING TOOLS 75 76 E 1 MICHELIN A better way forward CS 72 AND SPEED SYMBOL LOAD INDEX SPEED SYMBOL The ISO LOAD INDEX is a numerical code The ISO SPEED SYMBOL indicates the speed at associated with the maximum load a tire can carry which the tire can carry a load corresponding to its at the speed indicated by its SPEED SYMBOL under Load Index under service conditions
5. Evaluation X One tire vs Dual MICHELIN 2 d A better way forward OVER STEER Over steer is when the rear wheels are carving a larger arc than the front wheels or the intended line of the turn This is often described as a loose condition as the truck feels like the rear end is UNDER STEER Under steer is when the front wheels are carving a larger arc than the rear wheels This is often described as push or pushing as the front end feels like it is plowing off of a corner coming around 60 Over steer Very difficult to correct Under steer Very easy to correct Over steer is dangerous because once the rear end comes around the vehicle is uncontrollable and may enter a spin Braking only makes this condition worse Under steer is the more desirable condition because you have direct control over the front tires and deceleration usually corrects the condition The X One tire has a higher cornering stiffness and can generate more lateral force than standard dual drive tires Increasing cornering stiffness of the rear tires promotes under steer Additionally it will take more force to jack knife the vehicle CORNERING STIFFNESS FOR DIFFERENT TIRES 7 000 6 000 Q 5 000 1 2 0 e t p 3 000 0 7 7 2 000 Sen e 1 000 emm Michelin X One Tire Two dual 0 Conventional Wide Bas
6. No change in handling Slight lean depending on wheel position Vibrations Audible noise when rapid air loss occurs Immediate Actions Accelerate enough to maintain lane position DO NOT apply brakes immediately Do not apply maximum brake pressure to bring vehicle to a stop This stop should be gradual by pumping the brakes Creating assembly lock up can cause irrepairable damage to tire wheel axle components and vehicle Pull the vehicle to a safe area Do not attempt to limp further down the road Secondary Actions Turn on flashers Deploy safety triangles Inspect vehicle for damage Call for assistance This can be simplified by remembering the following and STOP In other words the vehicle lean or DROP may be the first indication of a rapid air loss Don t jam on the brakes Pumping the brakes will allow the damaged wheel end to ROLL to a STOP without lock up There are many Michelin X One tire training videos including rapid air loss handling and specific application demonstrations To obtain a copy contact your local Michelin dealer or the Michelin sales representative in your area TRACTION Traction is dependent on the following variables speed tread depth conditions dry or wet depth of water tread design tread rubber compound road surface concrete asphalt CHAINS Depending on the state in which you are traveling chains may or
7. Overall Width 8 Section Height 6 Free Radius 3 Rim Width 5 Overall Diameter 7 Nominal Wheel Diameter 9 Loaded Radius 10 Deflection 73 74 speeds are allowed Averaging four runs that are within 1 of each other then derives the RPM measurement Afterwards the results are double checked using shorter distances that are more easily obtained In addition to these the test tire is compared to a known baseline tire on a road wheel This latter method is very accurate and very repeatable when using a similar baseline tire with a known RPM The SAE procedure recognizes that within the test method itself there will be some variation In fact there are other factors that cause variation on RPM s among similar tires Be aware that they will have the same RPM The SAE procedure determines the RPM to within 1 5 Some factors which cause variation among tires are Load and Pressure A difference in Load Pressure could alter the RPM measurement by as much as 1 5 If pressure is constant going from an empty vehicle to a fully loaded vehicle can change RPM by 1 to 1 5 Treadwear The RPM varies from a new tire to a fully worn tire This can affect RPM by as much as 3 from the rated RPM Tread Geometry The height and stiffness of the blocks and the shape of the tread pattern can affect RPM Torque The presence of driving and braking torque can affect the RPM and Conditio
8. energy to the wheel through convection Much of the heat is transferred to the wheel in the bead mounting area due to its close proximity to the brake drum The wheel then directly conducts heat to the tire bead resulting in elevated temperatures in the tire bead area Duals Close to brake drum Excessive bead heat can affect tire life in many truck tire applications Vehicles in urban and refuse service are most commonly associated with bead heat issues but any application that experiences hard braking can be affected Results of bead heat 1 Immediate Failure In some cases after periods of hard braking where brake drums reach very high temperature in excess of 600 F immediate failure can occur This normally occurs when a truck is brought to a stop for a period of time with very high brake temperatures Often this occurs when an over the road truck stops at a truck stop at the bottom of a long descent As the heat rises from the brake drum there is excessive heat buildup in the portion of the tire bead directly above the brake drum inner bead of inside dual The high temperature can cause a breakdown of the rubber products in the bead area and allow the steel body cables to unwrap from the bead This process results in a tire rapid air loss This phenomenon is also common in urban and refuse fleets when the driver stops for a break after a period of hard braking 2 Premature aging of the carcass Heat is a tire s wor
9. may not be required If chains are required several companies have chains available for the X One tire The thing to remember when purchasing chains for your X One tire is tire size as the 445 50R22 5 chains don t fit the 455 55R22 5 and vice versa For more information consult your local dealer or go to www tirechains com is for reference only Chains specific questions chains manufacturer The information provided should be directed to the STOPPING DISTANCES Stopping distance with the X One tire is similar to that of dual A general rule typically mentioned in CDL manuals is to allow one vehicle length or one second between your vehicle and the one you are following for every 10 mph of your velocity For example if you are driving at 65 mph allow 6 5 seconds between your vehicle and the one in front of you A good way to practice this is to mark a spot such as a bridge road sign etc that the vehicle you re following has just passed and count one one thousand two one thousand etc to see how long it takes you to reach the same point If you count to only four one thousand then increase your following distance In wet and or icy conditions do not assume that because you have better traction that you will be able to stop quicker It is always the best practice to increase following distances and reduce driving speeds when traveling in adverse weather conditions LIMPING HOME Limp
10. mm e Recommended buff radius for X One XDA HT tread rubber is 1600 mm e Target circumference 3055 mm 3065 mm Recommended tread widths 375 mm 390 mm 455 55R22 5 e Recommended buff radius is 2000 mm e Recommended buff radius for X One XDA HT tread rubber is 1600 mm e Target circumference 3220 mm 3230 mm e Recommended tread widths 385 mm 400 mm Indicates wing style tread designs NOTE For non Michelin wing tread products contact MRT Duncan SC at 1 888 678 5470 then press 3 for Technical Support NOTE Using an improper buff radius or buff width could result in damage to the belt package irregular tread wear and reduced casing life Incorrect preparation of the casing for retreading will void the original warranty Recommended quantity limits represent repair guidelines based on the application of the tire in use General applications listed are Line Haul Pickup amp Delivery and Severe Use The performance requirements and usage demands differ for these applications and warrant different repair specifications Certain customers may have more stringent requirement that must be met for their needs Refer to your customer specific requirements to help ensure that their limits are met as well Also economic considerations may limit repairs below the number that is permitted for performance requirements and result in the rejection of casings Severe Use refers to off the road type appl
11. specified by service conditions specified by the tire the tire manufacturer manufacturer 1 kg 2 205 lbs Load Index Kg Lbs Ter 5 yr Speed Symbol Standard and Low Profile radial truck tire sizes can be more easily understood by breaking down the formula into the three components the section width in inches or millimeters aspect ratio and rim wheel diameter 1 Tire Size Standard Size example 11R22 5 11 inch nominal section width with a height between 90 and 100 of the section width radial 22 5 wheel diameter Low Profile example 445 50R22 5 445 millimeter nominal section width 50 is the aspect ratio expressed as a height to width percentage radial 22 5 wheel diameter 2 Aspect Ratio A nominal number which represents the section height divided by the section width expressed as a percentage Example 445 50R22 5 Aspect Ratio 50 3 Rims The approved preferred rims is designated for each size tire Michelin X One tires should only be mounted on the rims shown 4 Overall Width The maximum width cross section of the unloaded tires including protruding side ribs and decorations as measured on the preferred rim Overall width will change 0 1 inch 2 5 mm for each inch change in rim width 5 Overall Diameter The diameter of the unloaded new tire measured from opposite outer tread surfaces 6 Free Radius One half the overa
12. validated with 0 36 e 1 Computer simulation where whole vehicle is characterized mathematically 9 0 34 2 Track testing at our internal proving grounds 3 OE vehicle manufacturers in their independent 2 testing including tilt table testing 275 80R22 5 385 65R22 5 425 65R22 5 445 65R22 5 445 50R22 5 Source Recent evaluations at a Michelin facility in South Carolina Specifications for Tread Design A One PLUS Revs Load Catalog Loaded Radius Overall Diameter Overall Width Approved per Max Tire Load Range Number Si 4 Rims Mile Single mm in mm 405501225 3873 28 75 45 ss 18 1 45 1400 10200 120 4625 830 1 Comparison based on tractor equipped with 275 80R22 5 Michelin XDA HT mounted dual assembly on 8 25 22 5 inch aluminum wheels Specifications for Tread Design 24 Overall Min Dual Revs Load Catalog Tread Speed Loaded Overall Wee Approved T per Max Tire Load Max Tire Load Size Range Number Depth AN ze ES Rims FES ZZ REAR me SAME JACK KNIFE When you put the tractor and trailer into an extreme turn or jack knife situation the trailer is very vulnerable to rollover Normally traction has a positive influence on the handling of the truck This is no longer true when you put a truck in a jack knife condition Whether dual or
13. 23 24 33 45 52 62 74 Track Width Inside Cover 4 11 13 15 17 62 68 be ee EE 3 13 37 50 59 63 65 eege dE ENEE 13 14 19 46 48 CTCL 19 190000 Inside Cover 19 24 38 Under Steer 001010101 59 60 DE DAN 0017 3 52 54 66 KT 1 9 2923 2833 43 52 75 5 26 Valve mene 27 3 KT BE 5 19 23 24 26 27 33 2 1111310 1 1 1096 23 30 46 47 9 VET EE 3 18 23 30 31 38 39 45 48 50 54 75 Wear 315 ee 50 Wear Block e 23 45 11631 131016 23 46 Wear ee 23 45 Wear 1166 23 45 Wear COUN ees 23 31 38 39 45 48 54 Wear E 23 54 Wear Shoulder 23 30 38 46 Inside Cover 1 4 15 17 19 22 33 38 43 44 46 47 49 64 66 68 73 76 2 3 36 X One PIUS 2 3 36 37 62 74 2 00010100101 000 23 AONO 2 XS ORE 2 SS E Apper 111171112 40 2 Michelin Truck Tire X One Tire Service Manual To learn more please contact your Michelin Sales Representative or visit www michelintruck com To order more books please call Promotional Fulfillment Center 1 800 677 3322 Option 2 Monday through Friday 9 a m to 6 p m Eastern Time MICHELIN NORTH AMERICA INC G
14. 37 41 43 44 46 54 58 74 75 Inflation Central Tire InflatiOon 11 19 20 Inflation Over Inflation sss sss 19 37 39 43 Inflation Under Inside Cover oh E 24 34 39 42 52 53 58 Inner Liner e E 0 53 58 1 4 5 9 10 45 11151066 1011 Inside Cover 19 23 39 42 52 54 58 64 Inspection Pre Trip E 19 39 Inspection Retread Process 7 54 58 Inspection Tire 23 2 Inspection Valve Stem 5 19 23 24 26 27 52 Irregular 2 00000270 23 31 38 39 45 48 54 000001 59 63 6 Laurens Proving Grounds eege 68 11111111 Home 0 59 65 Load Product Specs Disclaimer 1 2 5 9 11 14 18 20 23 26 36 38 40 41 44 61 63 65 68 71 72 74 LO TCT ai GG O T E T A T 71 72 LO WEE 12 9 Long Haul Line 3 54 55 57 Lube Lubricants Lubrication 18 24 25 27 31 54 23 31 49 Missed 00 000 11 20 Mount Mounting 4 6 8 10 14 18 19 23 25 27 29 31 34 43 48 49 66 67 71 73 75 76 MOURNE 0 000000 as 24 71 75 Hole 0 0 0101071 Intro 53 57 11 1 000010 0 0 0 E O A 23 39 O O E E A OE E E A S 13 ON ON E 3 52 53 O a E E 5 24 000 27 91 48 75
15. 50 62 64 5 53107 31 43 5 230502 56011011116 2 E 53 57 EE 19 46 52 Severe Servic Severe USE 54 55 57 58 53 54 Shoulder Step 1 1 23 30 38 46 Sidewall Intro 1 2 10 17 20 24 26 30 31 34 35 38 40 41 44 50 51 54 56 57 65 EE 53 55 Specifications Intro Product Specs Disclaimer 1 4 9 11 15 31 44 48 49 53 55 57 58 62 KS e ee EE e A0 Specifications Repair 53 58 Specifications 111111011 49 Specifications Tandem SKEW E 51 Specifications e E E 41 Specifications 10 4 Specifications Trailer AlignMent 48 Specifications 1 9 10 51660 51111101 E 71 72 4 11 13 16 18 SPOP KE 58 97 Spread Axle 21 63 EE 1 4 6 8 10 24 49 52 0 007 beers eee ao AE O 2 510100 111 Et 39 59 65 8 SEIN 1 6 10 33 LIS E TONS elongata eee 24 25 28 9 Tanker Tin 0 0 0 0 00001010 Ea aaa ar 21 46 64 65 Technical 11111 an Intro 65 111116111111 0 0 00000 19 23 39 66 68 9 Temperature Logging 0 1 1 1 000000 68 69 TOONS asc ieee 24 25 29 47 49 71 75 76 TOONS Bead Breaking EE 24 27 75 TORO 1 2 5 7 8
16. IRS Crown area No damage to body ply cables rubber repairs only Crown Plies Only Protector Ply and Working Plies e Specified limits apply to rubber repairs greater than Size 30 mm diameter 2mm only Damages less than 2 mm deep are acceptable Crown Plies and Body Ply Casing Ply L 70 mm x W 25 mm or L 90 mm x W 20 mm or 120 7 SUGGESTED LINE HAUL Sid PICKUP 8 DELIVERY SEVERE USE date No limit if Body ply 10 per 20 per Body Ply Casing Ply damage visible per sidewall per sidewall 1 70 mm xW 25 mm to body but not 1 90 mm x W 20 mm or ply cables damaged 20 per tire 40 per tire L120 mm xW 15 L Length in radial direction W Length in circumferential direction Suggested Quantity is a suggested limit only There is no technical limit as long as the sizes are within specification However economic considerations will lead to a practical limit which must be determined by the individual shop management X ONE XZU S TIRE REPAIR RECOMMENDATIONS The X One XZU S tire is optimized for use in sanitation fleets This usage is defined as a Severe Use Application therefore the same repair specs that apply to the other XZU S products also apply to the X One XZU S tire Severe Use Application SIZE SECTION REPAIRS SECTION REPAIRS QUANTITY IN THE SIDEWALL AREA IN THE CROWN AREA 40 mm 80 mm 40 mm NAIL HOLE REPAIRS 10 mm diameter 9
17. amp Delivery 10 years For Severe Use no age restriction INITIAL INSPECTION Inspect X One casings as defined by your retread process manufacturer or industry recommended practices using appropriate equipment When using an electronic liner inspection device such as the Hawkinson NDT a new wide base probe of at least 275 mm 10 9 inches is required to help ensure sufficient and consistent cable contact with the shoulder upper sidewall area Hawkinson part PROBE ASSEMBLY 009 SHEAROGRAPHY If using laser shearography inspection per equipment manufacturer adjust and or modify to help ensure complete imaging shoulder to shoulder ND REPAIR RECOMMENDATIONS BUFFING An expandable rim width of 14 5 inches is required The beads of the casing should be lubricated with a fast drying non petroleum based tire lubricant Buffing should not start before casing reaches target pressure in the expandable rim as defined by your retread process manufacturer Recommended minimum inflation pressure is 1 2 bars or 18 psi Recommended tread width ranges are given below and may vary depending on the type and condition of the X One casing The X casing s finished buffed measured width should follow the same standards as other casings no more than 2 mm less than the width of the tread to be applied and no more than 8 mm more than the width of the tread to be applied 445 50R22 5 e Recommended buff radius is 2000
18. d possible injury Tire Dolly AX2 11000015 21 21 22 8 6 x 4 Tractors 22 2001111 0101010317 4 8 10 Air Verte 2023 34 35 Air Re Inside Cover 22 26 34 41 52 59 64 Pressure Inside Cover 5 10 20 23 31 36 39 44 47 64 A EAN 4 8 9 EE 23 46 48 Aluminum 6 1 4 6 8 9 24 49 52 62 Intro 3 4 6 8 14 15 21 38 46 55 57 58 64 66 74 EE 12 14 cloaca Inside Cover 1 4 10 11 13 14 18 19 21 23 33 36 38 44 48 63 65 67 73 Aale ONSI 13 4 Axle Identification 11 13 14 ANE SDa E 13 Axle 1 1 1 1 1 1 1 0000000000 23 47 01000 0 4 13 18 45 47 5 0 gees 2 ANE 0001010101 13 14 19 46 8 Axle Weight 4 11 13 14 5 EE 23 30 47 49 e 4 23 29 31 32 34 43 53 56 58 66 68 75 76 Bead Breaking 27 75 Bead Danta 000000 33 43 67 5 Bead EE 26 76 E aereraciere t eana EARE 53 58 BET E 11 14 18 111111 0001001000000 28 Block Edge 0000 23 45 Brake Inside Cover 7 8 13 19 23 46 59 64 69 Brake Skid Wed EG 23 46 1366 0000 59 606 8 Ee 53 54 Builder Retread 53 8 CEET GE 23 45 Centra
19. e 0 5 000 10 000 15 000 20 000 25 000 30 000 40 000 45 000 50 000 Normal Force Source Recent evaluations at a Michelin facility in South Carolina Contact Pressure HYDROPLANING Hydroplaning occurs when the tire loses contact with the road This can happen when the water pressure exceeds the contact pressure between the tire and the road Factors that increase likelihood of hydroplaning Excess water Excessive speed Low tread depth High tire pressure Light loads or bob tailing In other words if rain is pouring down and water is pooling the truck s speed needs to decrease in order to avoid hydroplaning 1 000 900 800 700 600 500 400 300 200 100 Rib Number Source Recent evaluations at a Michelin facility in South Carolina A tire s contact pressure can reduce your chance of hydroplaning The X One tire has higher contact pressure at the edge of the tread which provides a wider sweet spot than dual tires In the graph below you can see that the contact pressure is slightly higher in the center and significantly higher at the shoulders over dual fitments Note the drop in contact pressure for dual tires on the graph below For example the contact pressure of a dual tire is about 90 psi compared to 116 psi for an X One tire This will result in the dual tire losing contact with the road at lower speed than the X One tire This means if hydroplani
20. ggested limit only There is no technical limit as long as the sizes are within specification However economic considerations will lead to a practical limit that must be determined by the individual plant manager 55 Shoulder Shoulder Crown a Interior Crown Plies Body Ply Inner Liner Sidewall Sidewall A Bead B B Bead NOTE For truck sizes point B is located on the point of the bead point A is found 75 mm from B towards the interior of the casing and point A is also 75 mm from B but is located on the exterior of the casing Sidewall Damage Crown Damage Bead Damage Interior Damage 56 For all applications except X One XZU S casings Section Repairs are limited to a quantity of 2 For X One XZU S casings use specifications below sidewall and crown combined Maximum number of repairs 5 This is a total number of nail hole and section NAIL HOLE REPAIRS repairs with no more than 2 section repairs For example 3 nail holes 1 Sidewall Section Up to 10 mm in diameter in the crown area 5 1 1 Crown Section NOTE For best results nail hole repairs extending into the shoulder area should avoid having the repair NOTE The Michelin X One family has a unique reinforcement end in the flex zone of the casing 01 additional belt called Infini coil There are no special repair techniques or materials required SECTION REPAIRS SPOT REPA
21. her way to look at it is to take the total weight carried and divide by the stated Load Per Inch Width law to determine the appropriate size tire If a truck needs to carry 16 000 pounds an axle in a state with a 500 pound per inch width limit 16000 500 32 you would need a wide single tire that is at least 16 inches wide 32 2 In this case a 445 50R22 5 could legally carry the load 445 25 4 17 5 inches Metric to English conversion The two formulas are Load per inch width law x tire section width x number of tires gross axle weight limit Gross axle weight inch width law number of tires minimum tire section width needed State laws and regulations frequently can and do change so it is recommended that you consult your local State or Province DOT and where you will be traveling to be sure there are no restrictions on the use of the X One tire for your particular operation equipment and weight 65 BRAKE HEAT OVERVIEW Brake temperatures on trucks often reach very high temperatures Brake drums can reach temperatures of 600 F or more and are in very close proximity to the wheels This heat can be easily transferred to the wheels and tires Brake drum heat is transferred to the wheel primarily through radiation and convection The hot brake drum radiates heat in all directions to the wheel In addition the drum heats the air between the drum and the wheel The heated air rises and transfers additional heat
22. ications such as waste haulers cement mixers and logging operations Pickup amp Delivery refers to tires used for local areas only This category does not include mass transportation buses and other people movers These people mover applications are treated like Line Haul Line Haul refers to tires used for highway applications and any application not covered in the two special categories above SKIVING NOTE Buzz out limits are increased as outlined below due to the increased surface area of the X One tire over a standard size tire Buzzouts on Crown Diameter Surface Protector Ply Diameter 40 mm 3rd Working Ply or Surface 1600 mm Diameter 30 mm 2nd Working Ply Infini Coil or 1st Working Ply Surface 900 mm Bottom Crown Ply If edges of protector ply or 3rd working ply are frayed they may be skived if total area does not exceed 15 mm width on total circumference on one side 10 mm width x 200 mm length on the other side Crown damages up to 15 mm in length must be probed for separation or loose wires If the area is tight they should not be buzzed out Removal to top ply cables Maximum area at one point 20 mm e Maximum points around the casing 3 Protector Ply 3rd Working Ply 2nd Working Ply Infini Coil 151 Working Ply Bottom Crown Ply Suggested Quantity Line Haul Pickup amp Delivery Severe Use Suggested Quantity is a su
23. imits then they must be repaired NOTE If repairs are excessive economic considerations may lead to rejection of the casing BUILDER e Expandable rim width of 14 5 inches is required e Tread building should not begin until tire pressure has reached the target inflation pressures in the expandable rim as defined by your retread process manufacturer e For cushion to casing extruded bonding gum application recommended minimum inflation pressure is 0 8 bar or 12 psi 445 50R22 5 e Recommended base tread widths 375 mm 390 mm 455 55R22 5 e Recommended base tread widths 385 mm 400 mm Indicates wing style tread designs Note For non Michelin wing tread products contact MRT Duncan SC at 1 888 678 5470 then press 3 for Technical Support ENVELOPING Contact your envelope supplier for the recommended size envelopes to be used CURING Cure the X One casing according to cure law for the tread design per the retread process manufacturer FINAL INSPECTION Final inspection of the X One casing according to the retread process manufacturer work method and specifications OPERATION AND HANDLING 60 65 Over steer Under steer Hydroplaning Rollover Threshold Jack Knife Rapid Air Loss Procedure Traction Chains Stopping Distances Limping Home State and Local Regulations HEAT STUDY 66 69 Brake Brake Heat
24. ing on the X One tire can cause damage to the wheel and casing Although the tire is down it s possible that it is repairable unless it was run flat Limping home is never recommended even on dual tires DOT Regulation 393 75 states 393 75 Subpart Miscellaneous Parts and Accessories 393 75 Tires No motor vehicle shall be operated on any tire thal body ply or belt material exposed through the tread or 2 has any tread or sidewall separation 3 is flat or has an au dible leak 4 has a cut to the extent that the ply or belt ma terial is exposed EA b Any tire on the front wheels of a bus truck or truck trac tor shall have a tread groove pattern depth of at least gg of an inch when measured at any point a major tread proove The measurements shall not be made where tie bars humps or DL lets are located Except as provided in paragraph b of this section pei ehall have tread groove pattern depth of at least So ofan when measured in a major tread groove The measurement mre A Teen d if The following provides ten reasons not to limp home any tire TOP REASONS NOT TO LIMP HOME 10 Pavement Damage when the tire is run to destruction the wheel contact damages the road 9 Wheel Damage hundreds of dollars 8 Destroyed Casing it may have otherwise been repairable hundreds of dollars 7 Cargo Damage load shifts col
25. l Tire Inflation 11 19 20 Clamping 11 001010101011000 8 59 64 CIFCUMICTONIAl 0 0 0000 e Ss 26 40 54 57 58 EE 11 18 Contact PRC ee 61 Contact Surface Ratio 1 1 1 1 1 1 1 12 1 1 1 000000000 36 011101111113110 eege ENEE 51 5 40 45 57 58 11 11 R tread Process EE 53 58 Ree EE 13 14 Demount Dismount 4 23 27 29 32 34 43 67 5 Differential 000010 13 DO 21 6 WEEN 2 66 5 111 0 0 0 000100 4 13 18 45 47 5 IR AE 1 4 9 25 27 1181 Seal Valy 5 Dial DUIS Intro 2 4 6 13 14 18 19 23 24 32 34 36 28 41 43 45 47 49 59 61 63 65 66 68 69 74 Enveloping Retread e 57 62 EQUIVALENT 1 2 POO e et EE Inside Cover 36 37 63 F el 001010 0101011 2 3 8 2 13 33 Gross Axle Weight GAWR 2 4 14 65 Gross Vehicle Weight GVW 19 21 0 0 0011 eres eee 31 ee 31 38 53 55 Handing ena Inside Cover 22 37 39 59 63 65 76 HAVES EDICT ia ae 9 10 Heel TOE WESSELS RSG a 23 45 11111615001 EE 14 BUS EE 16 93 errr seer 59 61 Inflation Product Specs Disclaimer 9 11 19 20 23 24 26 31
26. lisions roll overs or fires 6 Collateral Truck Damage fairings tanks hoses brakes hoods mudflaps etc 5 Wheel and or Tire Detachment if the tire wheel become detached they become a projectile 4 Adverse Handling Conditions mishandled a runflat could lead to a jack knife or even a roll over 3 Direct D O T Violation fines and downtime 2 Creating assembly lock up can cause irrepairable damage to tire wheel axle components and vehicle 1 Endangers Other Vehicles and People heavy duty truck accidents can be fatal STATE AND LOCAL REGULATIONS Some states have enacted Load Per Inch Width regulations for the purpose of governing axle weight on primarily the steering axle of commercial vehicles These regulations provide a carrying capacity of a certain number of pounds per each cross sectional inch across the tire s width The determination of the tire s width can vary from state to state but presumably would be based upon either the tire manufacturer s published technical data for overall width or the width as marked on the sidewall of the tire which may require conversion from Metric to English units It is recommended to contact your state s DOT office to confirm the current Load Per Inch Width law For example if a state allows for 550 pounds per inch width a tire marked 445 50R22 5 could carry up to 9 636 pounds 17 52 x 550 or a total of 19 272 pounds on the drive axle 2 x 9636 Anot
27. ll diameter of the unloaded new tire 7 Nominal Wheel Diameter Diameter of rim seat supporting the tire bead given in nearest whole numbers e g 22 5 8 Section Height The distance from rim seat to outer tread surface of unloaded tire 9 Loaded Radius The distance from the wheel axle centerline to the supporting surface under a tire properly inflated for its load according to the load and inflation tables 10 Tire Deflection Free radius minus the loaded radius 11 Revolutions Per Mile Revolutions per mile for a tire size and tread is defined as the number of revolutions that the new tire will make in one mile Data is normally presented for the loaded tire at its rated load and inflation in the drive position A tire s RPM can be determined by measuring using SAE J1025 or estimated by calculating using a mathematical equation Michelin Equation RPM 20 1681 O D 8d O D Overall Diameter d Correction for deflection O D 2 SLR SLR Static Loaded Radius Michelin Truck Tire Service Manual MWL40732 At Michelin Revolutions Per Mile RPM are officially determined using the SAE Recommended Practice The test tires are placed as singles on the drive axle of the test vehicle and set to the corresponding pressure The vehicle is then driven over a straight 2 mile section at 45 mph while 6 number of revolutions are counted Since speed minimally affects the results for radial tires other 4
28. n of Pavement Asphalt vs concrete wet vs dry can create differences in RPM CALCULATED RPM Example 445 50R22 5 X One XDA HT Plus new tire O D 40 5 SLR 18 7 d 40 5 2 18 7 d 20 25 18 7 1 55 RPM 20 168 40 5 8 x 1 55 20 168 40 5 1 24 20 168 39 26 RPM 513 7 Calculated vs Data Book Measured RPM of 514 All the information required to determine the proper tire size is contained in the application specific data books To select the proper tire size for a vehicle it is necessary to know the maximum axle loads that the tires will carry and the maximum continuous speed at which they will operate The maximum load that a tire can carry is different if it is mounted in single configuration rather than in dual The allowable axle loads and the required inflation pressures to carry these loads are shown in the charts for both single and dual mountings in the current Michelin Truck Tire Data Book MWL40731 The maximum allowable continuous speed is also indicated Special tools are available to aid in mounting and demounting of the X One tire on off the wheel and the X One assembly on off the vehicle Due to the size of the tire and wheel these tools will assist the tire technician in providing both safe and easy methods of removal and installation When removing any tire from a wheel you should use an Impact Bead Breaker Slide Hammer to prevent bead damage This is al
29. ng occurs at 60 mph for the X One tire it will occur at 53 mph on the dual Contact Pressure Ratio 90 116 88 60 mph x 0 88 53 mph Dual Tires 1 ks Michelin X One Tire Dual Tires 2 9 11 61 62 ROLLOVER THRESHOLD There are two things you can change to make a vehicle more resistant to rollover Lower the center of gravity Increase your track width The X One tire does both let s see how First the loaded radius of the 445 50R22 5 X One XDA HT Plus tire is 18 7 275 80R22 5 XDA HT tire dual equivalent loaded radius is 19 0 See chart below For every inch you lower the Center of Gravity you gain 3 mph additional safety factor 74 6 Track Width with regard to rollover threshold Second the track width is measured at the center of where the load is distributed on the ground For dual this would be measured at the center of the 2 Of space between the dual For the X One tire it is simply measured from center of the left side tire to the center of the right side tire As you can see even though the overall width has reduced the track width has increased on the X One tire ROLLOVER THRESHOLD WITH TIRE SIZE 0 42 In summary the X One tire improves rollover Ei threshold by increasing cornering stiffness 0 40 increasing track width and reducing the center of gravity 0 38 o These improvements have been
30. reenville South Carolina USA MICHELIN NORTH AMERICA CANADA INC Laval Quebec Canada MICHELIN MEXICO S A DE C V Quer taro Mexico An Equal Opportunity Employer Copyright 2007 All rights reserved MWL43101 03 07 1 2 MICHELIN A better way forward ae
31. single configuration you are forcing the tires to stop rolling and slide sideways As the photo below clearly demonstrates the trailer is twisting because the tires are holding their position on the road This can lead to rollover This is especially true for spread axle trailers and high center of gravity loads Look at the lateral stress placed on the tires from the jack knife situation Turning angles should be minimized to avoid rollover threshold whether WARNING operating with duals or X One tires 63 64 NEVER exceed vehicle limitations because of improved handling A tire with a wider footprint is going to provide increased lateral stability when cornering As a result of this increased lateral stability the truck will have a tendency to lean less in turns The increased lateral stability should not equate to increased speed Always obey posted speed limits on the highways and curves A good rule of thumb for vehicles with high roll over thresholds i e tankers concrete mixers is to take the curves at the posted limit less 10 mph RAPID AIR LOSS PROCEDURE Even though the X One tire is an innovative product it still requires proper air pressure maintenance and visual inspection practices Tire failure can and will occur Below you will find a handy reference of the procedure to bring the vehicle to a safe stop following a rapid air loss event Indications Some or all of the following may apply
32. so a safer way to dislodge the tire beads from the wheel Never strike the beads with a hammer Impact Bead Breaker Slide Hammer AFTER YOU MOUNT THE X ONE TIRE ON THE WHEEL YOU MUST CAGE IT An extra wide Safety Cage is available for safe inflation of the tire In most cases a standard cage can accommodate the X One assembly DOT requires that all truck tires are to be inflated in an Inflation Cage WARNING Tire changing can be dangerous and should be done only by trained personnel using proper tools and equipment as directed by Federal OSHA Standard No 29 CFR Part 1910 177 Tires may explode during inflation causing injury to operator or bystander Wear safety goggles Keep all parts of body outside cage Use extension hose clip on chuck and remote valve Consult the Michelin Truck Tire Data Book MWL40732 for proper inflation 75 76 TOOLS FOR HANDLING THE X ONE TIRE Some people have difficulty standing on the tire ASSEMBLY using conventional mounting techniques and a good Tire and wheel dollies are available from Commercial device to help hold the bead in place without Tire Supply Companies to make the mounting and damaging the wheel are coated bead keepers shown removing of the assemblies on off of the vehicle easier here There are various types to choose Bead Keepers A tire dolly may provide the lifting assistance to mount or remove the X One tire assembly which may help to avoi
33. st enemy A tire subjected to high heat conditions over an extended period of time will experience accelerated aging of the rubber products The accelerated aging may result in a blowout during operation or it may render the casing unsuitable for retread The graph below demonstrates how operating with bead temperatures in excess of 200 degrees F will significantly reduce your casing life CASING LIFE vs BEAD TEMPERATURE 400 T 350 5 300 Ben 2 8 250 D 200 150 1 10 100 Casing Life hr 1 000 10 000 Bead damage result of brake heat is recognizable in 3 stages of severity In the first stage the bead starts to turn inward This can be visibly identified on the tire when it is dismounted A straight edge placed across the beads from one bead to the other no longer rests on the bead point but now rests closer to the bead bearing area 1st stage turning of the bead The second stage occurs when the rubber in the bead area starts to split or crack indicating that the steel casing plies are starting to unwrap 2nd stage bead splitting from heat The third stage is when the casing ply fully unwraps from the bead In extreme cases the casing ply unwraps from the bead all the way around the tire At this point the tire completely separates from the bead wire The bead wire can entangle itself around the axle if this type of separation occurs D 3rd stage complete un
34. wrapping of the casing ply 67 68 BRAKE HEAT EVALUATION X ONE TIRES VS DUALS X One tire fitments have greater clearance between the brake drum and the bead of the tire compared to a dual assembly In addition due to the 2 inch outset of the wheel for the X One tires more brake drum is exposed which provides greater air flow around the drum These characteristics reduce the heat transfer from the brakes to the tire and allow the brakes to run cooler Exposed brake drum This effect was demonstrated on a closed course at the Laurens Proving Grounds Michelin s 3000 acre test facility The Test A 4 2 straight truck outfitted with a temperature logging device was loaded to maximum legal limits and operated on a closed course with almost continuous starting and stopping cycles The truck was brought up to 30 mph and then stopped repeatedly for 45 minutes The temperature logging device recorded brake drum and wheel temperatures in the bead area every 10 seconds The test was run on both X One tires and duals at similar track temperatures and weather conditions After 45 minutes when the brakes were at their peak temperature the temperatures from the data loggers were compared The brake drums fitted with X One tires were over 100 F cooler and the wheels were over 30 F cooler in the bead area than when equipped with Duals BRAKE TEMPERATURE X ONE TIRES vs DUALS 700 600 500 400 degrees F 300
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