Motorcycle TiresReading Tires - What's important - Tire Links5 Questions you should be able to answer about your motorcycle tiresNo trick questions, this is an open book test, you can check your tires to answer these 5 questions:
Make and ModelThe make and model of your tire is probably the least important information, probably only useful for bench racing, but very often that is the easiest to spot.
Rim DiameterThe diameter of your rims is probably something most riders know, and even if you know very little about your bike, it's a difficult thing to mix up - 16" tires simply won't fit on 17" rims, so it's not likely something that can get mixed up while your bike is in the shop.
Tire SizeThe tire sidewall includes size information, usually now seen in metric (although there are inch designations and an alphabetic system too) which includes the width or section of the tire in millimeters, and the height of the tire as an aspect ratio (section height divided by section width multiplied by 100).
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In the markings on the sidewall of the tire on the right, you may be able to make out the marking 150/60R18. This is, in a round about way, the tire size information in metric.The first number, 150, is the section or width of the tire in millimeters. The second number, 60, is the height of the tire, as an aspect ratio (60%). The 'R' designates this tire's construction method as a radial tire, and you may also see 'B' or 'BB' for bias belted. The final part of this tire size is the last number, 18, the rim diameter in inches (yes, even in the metric tire sizes there are inches). The other markings you can see in this picture include an arrow, pointing towards the tread, showing the location of tread depth markers or wear bars within the treads.
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Other markings you may see on tire side walls includes a directional arrow, showing the rotational direction of the tire when mounted correctly. You may see a coloured paint spot that indicates the balance point in the tire.
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On the tire on the left you might be able to see the designation 110/70ZR17, another metric tire size marking. This is a narrow 110 mm front tire, 70% as tall as it is wide. The 'Z' designation is a speed rating, and the 'R' denotes radial construction. The final '17' indicates a 17 inch rim.Following these larger markings you may be able to make out the Load Index, a numeric code that equates to a weight in kilograms of the Tire Load Capacity. On this tire '54', followed by the Speed Index, 'W' on this tire.
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The speed and load rating of your tires are very likely to fall within a suitable range if the above criteria are met, but it's a good idea to check and make sure you'll be operating the tire within it's expected parameters.
Speed Ratings
Load RangesThe load index noted on the tire photograph above is '54' - which equates to a tire load capacity of 212 kg.
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Your tire's birthdayThis is probably the most critical and least known tire marking. This is a 4 digit number expressed as week and year (WWYY). Tires, like your helmet, are only good for 5 years, even under ideal circumstances. Modern tires contain volatile organic compounds that leach our over time in a process called de-gassing. Even tires stored in ideal conditions and never mounted on a rim are 'dead' after 5 years. Buying tires a few years old may not matter if you go through two sets of tires a season, but if your tires last you a few seasons, you won't want to mount an old tire. Prior to 2000, a three digit tire date of manufacture was used, and you definately should not mount a tire that old.
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Why all this important to understandMake and model of your tires may be something that your benchracing buddies ask you, or other people who have the same kind of bike might inquire what tires you've tried. Otherwise, the make and model of your motorcycle tires probably isn't of much importance to anyone but you.The diameter of your rims determines what sizes of tires will fit your bike. When shopping for tires it's an important specification to bear in mind. If there is a particular tire that you really want, that is not available in your rim size, you've got some pretty major modifications to change your rim size, although it's not impossible. The size of your tires is very important. The width and height of the tire, which combine to create the profile of the tire, are critical. In some cases it's possible to fit a slightly oversized or undersized tire onto your rim. But just because it seats the bead, holds air and doesn't rub on any hard parts doesn't mean it fits properly. Many riders (and occasionally people selling tires) are under the mistaken impression that a wider tire offers a bigger contact patch (accurate in straight line applications) or that a narrower tire will offer quicker steering. Larger or smaller rims do offer different handling characteristics, but fitting the wrong sized tire to your rims will distort the profile of your tire. The shape that the tire becomes when it is mounted on your rim is critical. With a tire of the correct profile, the size and shape of your contact patch will remain the same while cornering as in a straight line. This is not true of an oversized or undersized tire, on which the contact patch can decrease in size at extreme lean angles. Be very cautious trying tires that are not correctly sized for your rim. The speed and load rating of your tires is important, but considering how uniquely sized modern motorcycle rims are, it is unlikely that you will encounter an unsuitable speed or load rating in a tire that has the correct size specifications, unless you are using your bike in a non-standard application like racing. The date of manufacture of your tires is a critical detail to consider. The decline in tire quality due to de-gassing is an on-going process, and a newer tire will offer better grip and traction than an older tire. While a tire may last 5 years under ideal conditions, it may also decline more quickly due to exposure to the elements, extremes of temperature, heat cycles, improper inflation or other factors. It makes sense to get the freshest tire you can.
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More reading about motorcycle tiresMore details on reading tires - from AMA:http://www.amadirectlink.com/roadride/Riderresc/tires.asp
Dunlop Tire Information:
Glossary of Tire Terms (from Dunlop)
Maxxis Tire School:
Bridgestone Tire PDF from Trackaddix.com
Good informational article:
Tire inflation warnings:
Tire Sense tips:
General Tire tips:
Basic tire tips:
Rim size to Tire size chart - NaughtyBoy MotorRacing:
TIRE Manufacturers websites:Avon: www.avontyres.comAvon Motorcycle Tires: http://www.avon-tyres.co.uk/motorcycle/
Bridgestone:
www.bridgestone-usa.com Cheng Shin: chengshintires.com/index2.html
Continental:
www.conti-online.com Dunlop Motorcycle: www.dunlopmotorcycle.com
Kenda: www.kendausa.com
Maxxis: www.maxxis.com
Metzeler:
www.us.metzelermoto.com Michelin: two-wheels.michelin.com Pirelli: - www.us.pirellimoto.com
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