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motorcycle tyres (tires)

Discussion in 'The Garage' started by inxs, Dec 12, 2009.

  1. inxs

    inxs xx

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    - http://www.amadirectlink.com/roadride/Riderresc/tires.asp

    How to read a motorcycle tire

    By Bill Andrews

    [​IMG]

    It's a rotten feeling. You look down at your tire, and there's no denying that those nice deep grooves have become a shadow of their former selves. It's a goner, and it's getting worse with every mile.

    As you look around your local motorcycle shop for a new tire, you see all sorts of letters and words on the sidewalls. Would you believe just about everything you need to know about a tire, including when it was made, is contained there?

    It's really not that difficult to decipher the black art of tire designations, and knowing what you've got makes you a well-educated consumer-which is never a bad thing.

    Tire size

    First off, there's those big numbers and letters that may read something like 130/90 16, or MT90 16. These numbers indicate the size of the tire, and the rim it's designed to go on. In this case, these are both the same size tires.

    How can we tell?

    Let's start with the first series of numbers, 130/90 16, otherwise known as the metric designation. This is the most popular nomenclature today and it's practically a standard in the automotive world.

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    The 130 designates the tire's width in millimeters, measured in a straight line through the tire from one edge of the tire's tread to the other. The second number, 90, is a bit trickier to understand. This represents the aspect ratio between the tire's width and its height, or how tall a tire is in relationship to its width. Simply put, the higher this number is, the taller the tire will be. In this case, the tire is 90 percent as tall as its width, or 117mm.

    The last number, 16, is the tire's rim diameter expressed in inches.

    The width on some tires may be expressed in inches as well, but usually the aspect ratio is left off.

    The other series of numbers and letters, MT90 16, represents the same tire size, but it's expressed in an alphabetical code. M means the tire is designated for motorcycle use, T is the tire width code, 90 is the aspect ratio and 16 is the rim diameter.

    Size conversion chart

    Front tires.....................Rear tires
    Metric...Alphanumeric..Metric.....Alphanumeric
    80/90 .... MH90.......110/90.........MN90
    90/90 .... MJ90........120/80........MP85
    100/90 ... MM90.......120/90.........MP85
    110/90 ... MN90........130/90........MT90
    120/90 ... MR90........140/90........MU90
    130/90 ... MT90........150/80........MV85
    ...............................150/90........MV85

    The alpha numeric system is the older method for tire sizing. And in the old days, tires just didn't get much bigger than an MV85, which corresponds to a 150mm width. Therefore, newer tires larger than 150mm will only carry the metric sizing designation

    Speed and construction

    Interspersed with these sizing numbers, you're likely to find other letters that'll appear as such: 160/70VR 16, 170/60R 16V, or in other combinations. These two extra letters indicate speed rating and tire construction.

    Each letter in the speed rating notes the maximum speed a tire can sustain under its recommended load capacity. For instance, V is equivalent to a maximum speed of 149 mph. Because this rating system was created in Europe, the increments per letter are in 10 kilometers per hour.

    Rating Speed mph Speed kmh

    Q .....99 mph ......160 km/h
    S ....112 mph ......180 km/h
    T ....118 mph ......190 km/h
    U ....124 mph ......200 km/h
    H ....130 mph ......210 km/h
    V ....149 mph ......240 km/h
    W ...168 mph ......270 km/h
    Y ....186 mph ......300 km/h
    Z ..Over 149 mph ..Over 240km/h

    The next letter, R, indicates the construction used within the tire's casing. R stands for radial construction and B means belted bias.

    Load and pressure codes

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    The next number or letter you may encounter, after the tire size, is the load index. This is the weight the tire is capable of handling when properly inflated. It's usually expressed in either a numerical code, or a letter code. Most manufacturers will also spell out on the sidewall what that maximum load is so there's no guessing—you'll find it usually listed with the tire's maximum air pressure.

    It's good to note here that you should only fill a tire to the motorcycle manufacturer's recommended level. Besides under inflation, one of the biggest mistakes people make with their tires is to overfill them to the maximum level indicated on the sidewall. This leads to poor handling and premature wear. If in doubt, either consult your owner's manual, contact your local dealer, or go to the tire manufacturer's website. Most include the recommended pressure for each motorcycle, along with other tire options. And be sure to measure pressure when the tire is cold. Measuring hot will skew the numbers.

    Rotation and balance marks

    One of the more critical marks on a motorcycle tire is the rotation arrow, or arrows. Today's specialized tires generally have a tread pattern that must go in only one direction. Some manufacturers even state that their tread patterns are designed to disperse water, and by mounting the tire backwards, they won't work.

    The other big reason for noting wheel direction has to do with the manufacturing process. The tread rubber is initially a flat strip that's cut to length, at an angle, and then spliced together with the two ends overlapping, creating a hoop. Under acceleration, a tire mounted backwards will try to peel back this splice. The opposite is true for the front wheel, where directional forces are reversed under hard braking.

    Another mark to look for when mounting a tire is a painted balance dot, or dots. Most tires are pre-balanced by the manufacturer. They will then put a mark on the tire indicating where the valve stem should line up.
    Born on date, and wear's the tread?

    Other useful information on the tire's sidewall includes its manufacturing date. Look on the side for a raised block with four digits; it's usually next to the U.S. DOT tire identification number. The first two indicate the week of its manufacture, and the last two are for the year. For example, 1702 would indicate the tire was manufactured in April, 2002. Prior to 2000, there were only three digits, with the last one indicating the year.

    Some tires may have raised triangles, or the letters TWI, to show where the tire wear indicators are in the tread. When these marks are equal to the tread, it's time for new tires.

    Anything else?

    [​IMG]

    Other information on the sidewall is usually spelled out; "tubeless" or "tube type" may be substituted with the letters TL or TT respectively, and the tire ply, composition and materials used may also be spelled out.

    Now you know all you need to know to have an intimate conversation with the black hoops around your rims.

    Tire links:

    Avon
    www.avontyres.com/

    Bridgestone
    www.bridgestone-usa.com

    Cheng Shin
    chengshintires.com/index2.html

    Continental
    www.conti-online.com

    Dunlop
    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

    Key to Tire Designation Codes

    Speed Rating

    - Sustained speed rating letter codes:
    N - 93 mph (150 km/h)
    S - 112 mph (180 km/h)
    H - 130 mph (210 km/h)
    V - 149 mph (240 km/h)
    Z - 149+ mph (240+ km/h)

    Tire Size

    Wheel diameters are usually in inches and tire width in millimeters or a letter designation.

    Tire Widths

    mm .. letter .. inches
    80 ... MH ... 3.00
    90 ... MJ ... 3.25
    100 .. ML ... 3.50
    110 .. MM .. 4.00
    120 .. MP .. 4.50
    130 .. MT .. 5.00
    140 .. MU .. 5.50
    150 .. MV .. 6.00

    Shoulder Heights

    - stated as a percentage of the tire width as in the following tire designation.
    100/90V18
    - 100 is tire width in mm. 90 is the shoulder height - 90 percent.
    - V speed rated or 149 mph.
    - 18 inch wheel.

    D.O.T. Number

    - tyres also have a D.O.T. number. the last three digits showing the year and week of manufacture - e.g. 324 .. made in the 32nd week of 1994 or 1984 if unlucky
    - tyres deteriorate with exposure to sunlight, ozone, and aging - always ride as new as possible
     
  2. inxs

    inxs xx

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    - what are your favourite tyres?

    - is there a reason for this?

    - where do you get them from?
     
  3. angus67

    angus67 Welder's penetrate deeper!!

    I have bridgestones on my suzy, and they are soo dead. just waiting for moneys now.
    At one point, I had low pressure on my front, and so now I have almost no tread on my sidewalls. And my rear is a goner too, but its only worn in the middle, so the front will be replaced first.

    This is very confusing to me, as I just put my snow tires(tyres) on my Honda, and they say 44 psi max. I did that, and drove maybe 20 miles(30klm?). They were really loud, and hard. when I asked on-line at a forum, nobody really could answer what i should run them at, so I dropped pressure to 35psi. So, should we use the vehicles recommendations for pressure, or tire manu reco. for pressure?
    Because it seams to me that if we hard-tail, strip, weight reduce, bob, we will be lightening up our bikes, and I think my bike is a lot lighter than stock weight. I can 'skid' my bike around in a circle, were as my friend's 72 I cant budge.
    So with that said, if my bike is alot lighter than stock, and since its a hard tail, what pressure would you recommend to soften the ride without sacrificing treadwear?
    Exellent topic for sticky, btw;)
     
    Last edited: Dec 12, 2009
  4. Travis

    Travis Staff Member Staff Member

    Angus, I usually run about 33psi in most of the cars I've owned. If I see the middle of the tires wearing out faster than the tread closer to the sidewall, I'll lower it a couple of psi. If the opposite is happening, and it's not because of cornering fast or worn suspension parts (ball joints, tie rod ends) I'll raise the pressure a couple psi.

    For motorcycles I usually run about 32psi in the front and a few pounds more in the rear. It all depends on the bike but if it were hardtailed, I'd probably lower the psi in the rear quite a bit to get a better ride. You're probably not really carving up the corners or doing 140mph on your hardtail anyway, and the reduced stress on your back would be more than worth the cost of replacing your rear tire more often.
     
  5. angus67

    angus67 Welder's penetrate deeper!!

    Yeah, canyon carvers arn't usually hardtailed. And I dont really plan on blasting down the highway for extended times, Since I live mostly in a rural area anyways, the top speed I'l prolly see for any length of miles could maybe top 70 mph. I'll definateltly try to keep the rear soft.
    Thanks for re-quoting that for me.
     
  6. crash

    crash XS650 Junkie

    i agree with travis:bike:
     
  7. XSLeo

    XSLeo XS650 Guru

    I learned along time ago how to figure out the best tire pressure on anything with tires.
    Set the cold pressure to whatever you feel is right, drive the vehicle for 15 to 20 minutes at highway speeds, this gets the tires warmed up, stop and check the hot pressure, it should show a 3 to 4 psi increase above the cold pressure. If the increase is less than 3 psi the cold pressure is to high, if more than 4 psi the cold pressure is to low.
    The change to the psi is caused by heat build up in the tire. Too much cold pressure won't let the tire flex enough to warm up, to little cold pressure flexes the tire to much.
    The proper amount of flex warms the tire to the right temperature. It also gets the max performance from the tire. The vehicle will accelerate, brake and handle better. tire life and gas mileage will be at there best too.
     
  8. yamaman

    yamaman xs650 addict

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    Dunlop TT100gp, they look cool, they handle cool (wet or dry) they wear cool, they must be cool! :thumbsup::bike:
     
  9. 80xs650

    80xs650 XS650 Enthusiast

    Is there a difference between the TT100GP and the TT100 that places like BikeBandit sell in the US? Thanks.
     
  10. Gordon

    Gordon XS650 Junkie

    Xs Leo has the correct formula for finding the tire's best pressure to run. The tire pressure not only will get you the best milage/ride/wear, but also prevent premature failure. Too soft or too hard will result in stressing the construction / belting of the tire. Both create heat, & heat will ruin the tire.
    Auto man. have listed on the door sticker the proper amount of pressure's. What is on the sidewall of a tire is the MAXIMUM amount of air pressure, for the MAXIMUM load! I don't run around with the vehicle loaded to the hilt all the time, so I don't use the maximum pressure.
    I like the Dunlop 404, I get them very reasonable from a distributor. Sorry guy's,that's the business I'm in.Cannot wholesale to anyone.You can get some good deal's online, just be aware that they are gonna send you the oldest tire's they got. All wholesaler's do that. Rubber deteriate's with age, from what is called 'ground level ozone'.
     
  11. Hey Gordon, great minds think alike ( or is it, fools seldom differ :doh:) ........................I use the Dunlop 404s on front and back. They're not expensive, seem to wear fine and grip is good. I find 31 psi for both tires works OK.
     
  12. Travis

    Travis Staff Member Staff Member

    XSLeo and Gordon, that's great information on correct tire pressures! I'm surprised I haven't run across that before! I'll have to check my vehicles and see where I'm at. Do you guys ever run different pressures front and rear on passenger vehicles using that method? Also is the 3-4 psi figure the correct one to use even with the lower profile tires motorcycle and car manufactures seem to be using these days? For example, my Honda Accord has 235/45R18 tires on them which are factory wheels and my FZ1 has a 190 rear.
     
  13. inxs

    inxs xx

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  14. Los D

    Los D XS650 Enthusiast

    Anybody have any experience with the following tires?:
    Dunlop K70 front and/or rear
    Bridgestone Trailwing TW101 front and/or TW42 rear
     
  15. Los D..........Yes, I've ridden two XS 650's both on and off pavement with TW 42 rear tires and liked them very much. FWIW however, I consider the TW 39 on the front to be a better match as a set with the TW 42 than the TW 101. Please note: I don't mean to imply that the TW 101 isn't as good a tire....in fact I wish that design (TW 101 front and TW 152 rear) was available in our 16",18" rears and 19" fronts....it's not.

    Ditto: the Avon Distanzia (available in 18" R & 19" F) Very nice combo btw but $$

    The TW 39 (19" F) with either the TW 40 (!6" R) or TW 42 (18" R) result in the best fitment set of (80% on-20%off) dual sport tires I've found so far. These (XS 650) sizes are, as you may have noted.....not today's bikes or market's most common.

    Best, Blue

    Track these down on one tire site or another. The pictures tread pictures and fitment sizes tell the story!
     
    Last edited: Jan 25, 2010
  16. Los D

    Los D XS650 Enthusiast

    Thanks Blue, the TW101 for the front has already been ordered so I'll just have to keep you posted on it's performance. They will definitely see more road than dirt, but with the amount of camping coming up this year, I had to get something with a little traction.
     
  17. XSLeo

    XSLeo XS650 Guru

    The formula works with any tire, at least with any tire I have ran. It works at high outdor temps, low out door temps. Light loads or heavy loads. Or any where in between. As gordon mentioned And I forgot is that the pressure on the side of the tire is the MAXIMUM pressure the tire is designed to carry. If your testing of the cold to hot pressures indicate you need to run more pressure than the sidewall pressure, you should get a stronger tire. With most bike tires this won't be a problem unless you have a dresser or tourer that carries two up with a heavy load.
     
  18. Backroader

    Backroader XS650 Addict

    The tires on my 1978 XS are Yokohoma Speed Master 990...not having much luck trying to get information on them.... the tires may be extinct, ha, ha,

    Looks like they are 1978 vintage ... the indicator on the tire reads as follows DOT FEXR (AFX088) , though there is no sign of weather checking I am hoping they pass the Safety Check here in Manitoba... tires in Canada are so expensive as compared to the US. Cost me $500.00 for a set of Metzler Karoo 2 supplied and installed for my F800GS last year.
     
  19. 80xs650

    80xs650 XS650 Enthusiast

    I removed a set of Yokohama World Tour 955 tires from my 1977D last weekend. The rear was worn flat, and they did look 1977 vintage. :yikes:

    I'm looking at replacing them with the Dunlop GT501 or the Avon AM26. The Dunlops are about $200 for the pair, the Avons a little cheaper. I've read good reviews of both tires.
     

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