MAINTENANCE

 

"Tire safety maintenance and mounting advice"

  

INFLATION PRESSURE
Many tire damage result from incorrect inflation pressure. Furthermore, the inflation pressure has a big influence on the riding qualities of a motorcycle. The inflation pressure recommended by the motorcycle manufacturer can be found in the bike's manual and is usually written on a sticker on the rear swingarm or chainguard. Set the suggested inflation pressure on cold tires before riding. During service the tire's warming-up causes a pressure rise that must NOT be reduced.  
Check inflation pressure once a week. Increase rear tire pressure by 0,2 bar / 3 psi when riding with a passenger or with very heavy load. Insufficient inflation pressure causes tire flexing and overheating that may lead to internal damage. Overinflation impairs riding comfort and stability and can result in uneven wear. When checking the inflation pressure, don't forget to lock the valve cap. Use a valve cap with rubber sealing.

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LOAD CAPACITY AND SPEED RATING
Load Capacity and Speed Rating are included in the size description. The load rating of a tire is identified by a code-number and must not be exceeded (observe max. permitted vehicle weight). The max. permitted vehicle weight might be exceeded when loading the bike with passenger, saddle bags, a trunk bag, etc. for longer trips.
METZELER does not recommend the use of trailers nor does METZELER give warranty for tires used with trailers except the reinforced version of the Marathon-Touring lines. The max. permitted speed of a tire is indicated by a code-letter. Please refer to the conversion table for load and speed index explanation .

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TREAD DEPTH
Legally the tire has to be changed as soon as the remaining tread depth is below 1,6mm. This can easily be checked by controlling the tread wear indicator height.
These indicators can be found into the tread pattern grooves, correspondingly to the "TWI" sign on the tire's sidewall. METZELER recommends changing tires when the remaining tread depth is below 2 mm .

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NEW TIRE
When fitting new TT (tubetype) tires, new tubes have to be used. Tubes become stretched in service. If a used tube is fitted in a new tire, it can crease and fail due to thinning of the tube rubber. When fitting new TL (tubeless) tires, a new valve should be fitted for safety reasons. Under acceleration and braking, as well as during continuous riding at elevated speeds, the centrifugal forces acting on the valve can bend it down up to 90°. Therefore, short valves should be used. At speeds above 200 km/h, the centrifugal forces acting on the valve insert become so high, that the preload of the valve spring might not be enough to keep the valve closed. Short valve inserts have a higher preload than long ones. Even better are short inserts with a red Teflon-ring. These have further increased spring preload. Whichever type of valve insert is used, it is very important to carefully tighten the valve cap. METZELER recommends to use only caps with rubber sealing. METZELER-Tubeless-Tires may be fitted to Tubetype-Rims, if the following restrictions are kept:

• Use only METZELER-tubes Tubeless tires fitted with a tube have a max. permitted speed of 230 km/h.
• See "Mounting Advice".
• The repair of a punctured tubeless tire by means of fitting a tube is not permitted.

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CLEARANCE
Sufficient clearance under all riding conditions is important to prevent the tire from touching the mudguard, fork or swingarm, etc. Due to the centrifugal forces, the overall tire diameter increases with speed.
This dynamic growth can be considerable especially for bias tires. Be careful with respect to changes of the wheelbase, e.g. caused by adjustment of a worn-out chain. Keep the adjustment within the limits shown on the swingarm.

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RIMS
The section "Technical Data" informs about all the permitted rims for that size; the one written in bold is the suggested one. Motorcycle tires must be fitted to motorcycle rims only. New tire marking description foresees the M/C symbol on the sidewall to identify tires that can be fitted on motorcycle rims only.
The correct rim width is important for handling characteristics and stability. Fitting a tire to a too narrow or wide rim changes the tire profile and gives a negative effect to the overall tire performance .

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MIX OF BRANDS
Different brands of front and rear tires can lead to riding problems. Unfortunately METZELER is not able to test the METZELER tires in combination with all competitor tires, therefore - for safety reasons - we have to insist in suggesting you to always fit METZELER tires both on front and rear.

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DIFFERENT SPEED CATEGORIES
The use of a tire with higher speed index rating (e.g. "H" instead of "S") is permitted only if listed in the fitment chart. In any case, especially for speed ratings over 210 km/h the recommendations in the METZELER fitment chart have to be respected.

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DIFFERENT CONSTRUCTIONS
We distinguish three different constructions: Bias tires = "-", bias belted tires = "B" and radial tires = "R". These different constructions feature different reaction capabilities to side and longitudinal forces. Therefore a combination of different constructions between front and rear can influence the motorcycle overall behaviour. Only the tire combinations listed in the motorcycle manufacturer's and tire maker's fitment charts are permitted.

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DIFFERENT COMPOUNDS
The fitment of tires with special compounds dedicated to a more sporty use like "CompK" or "Racing" should always be done on both front and rear tire. In special cases contact METZELER for exceptions.

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DIFFERENT PATTERNS
METZELER motorcycles tires are designed to be fitted with the same model (tread pattern) front and rear unless indicated otherwise by Metzeler or the manufacturer.

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DYNAMOMETER TESTS
Dynamometer tests can put extreme stress to the rear tire and might cause internal tire damage, invisible from the outside, that can lead to a sudden tire defect when the tire is further used on normal road.

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TIRE REPAIR (TUBELESS TIRES)
According to the specific regulations of different country governments, a general recommendation regarding tire repair cannot be given. For your country, please refer to your distributor. In case a repair is permitted, METZELER is only recommending the repair of small punctures restricted to the tread area using a mushroom head type plug. The repair of a punctured tubeless tire by means of fitting a tube is not permitted .

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REGROVING
It is not permitted to regrove or cut the tread pattern of motorcycle tires, as this might affect negatively the riding performance and safety.

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TIRE STORAGE
Store tires in a cool, dry, dark and moderately ventilated area. The storage temperature should not vary in an extreme way but keep a level below 25° C / 77° F. Direct contact with pipes and radiators must be avoided. Ozone will accelerate tire aging, therefore do not store tires near electric motors or other equipment, which may produce sparks or other electrical discharges because this produces a higher concentration of ozone. Contact with oil or gasoline may cause contamination of the rubber compound making the tire unsuitable for use. Wipe off any oil or gasoline immediately with a clean rag .

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MOUNTING ADVICE FOR METZELER TIRES
Motorcycle tires were originally specified by the manufacturer. Any other use could be dangerous. Check for directional arrows. If present, mount tire so that arrow points in direction of rotation. Some METZELER tires have a red dot in the tire sidewall to indicate the lightest point which should be positioned next to the valve. Clean and lubricate bead with tire mounting lubricant or soapy water.
To set bead:

• Remove valve stem core and inflate tire.
• In case device used permits inflating only with valve stem core installed, deflate a tube-type assembly after bead has seated, then reinflate to recommended riding pressure to allow the tube to seat properly.
• Do not inflate more than 40 psi. Reinstall valve stem core and inflate to recommended riding pressure. Check bead control lines for proper seating. If the beads do not seat, deflate and repeat above procedure. METZELER tubeless tires may be used with METZELER tubes on tube type rims. When installing a tube in a METZELER tubeless tire do not tighten valve stem lock nut until tire is seated and inflated to proper riding pressure. Whenever you fit a tube care should be taken not to pinch the tube. Dust the tube with talcum powder. Always use a valve cap with rubber sealing .

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WHEEL BALANCING
Elastic bodies like tires cannot be produced absolutely round without imbalance. Therefore always balance after fitting a new tire. There are two methods: Static and dynamic balancing. Static balancing can be made without spinning wheel. Dynamic balancing can only be made with a rotating wheel and measures also the deviation of masses in respect to the wheel centre plane. METZELER recommends dynamic balancing for rims over 2.5-inch width.
Caution: To avoid the danger of air leakage use only weights that are recommended from the motorcycle manufacturer like spoke nipple weights, lead wire or self-adhesive rim weights. METZELER does not recommend the use of liquid balancers or liquid balance/sealers. METZELER does not give warranty for tires into which these have been injected .

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WHEEL ALIGNMENT
Be sure to align your wheels each time the rear wheel is removed or the chain adjusted. Each revolution of an incorrectly aligned wheel gives addition tread wear, reduces tire mileage and negatively influences steering and cornering, leading to bike instability .

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RUN-IN
After fitting, the tire should not be used with maximum power or hard cornering and not over 60 mph for the first 100-150 miles. This is needed to allow the tire/rim assembly to adjust properly and most of all to let the compound find his optimum working conditions .

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TECHNICAL DATA
Speed Index Table
Load Index Table

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