Tire Information

I've been collecting some information about tires, how to change tires, how to convert tire sizes, what all those numbers on the tires mean, where to buy tires, etc.

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On this page:

Wheel Bearings
How old are my tires?
Changing Tires
Tire Vendors
Balancing Tires
Tire Size Conversion/Speed and Load Rating Chart
Tire Size vs. Rim Width Chart

Top of page A Word About Wheel Bearings

On the GS shaft drive bikes, the front bearings are part number 6302, and the rears are 6303. You'll need two each as you always replace them as a set.  They are sealed on one side. Install the sealed side towards the outside of the wheel.  If you can, get "2RS", which means "2 rubber seals" (6302-2RS and 6303-2RS), sealed on both sides. These are industry-standard designations. If you look up the Suzuki part numbers, you'll see the standard
bearing number is embedded.  Note that the bearings are standard metric sizes and are available anywhere there are machines.  You can also find them at Z1 Enterprises, All Balls Racing, and other bike vendors (see the info/links page).  If there are spacers between the bearings, don't forget to put them back.

(My thanks to Mr. bwringer for providing the above information.)

Top of page How old are my tires?

There is a code molded into the sidewall of your tires.  The codes give you information such as size, speed and load ratings (see the charts below), manufacturer, the plant where it was manufactured, etc.  The most important code is the date code.  It should be a 4-digit code at the end of all the other informational codes.  

Note: If your tires have a 3-digit code, the first two digits are the week and the last digit is the year.  That means the latest they could have been manufactured is in 1999!!  For example, a code of 109 would be the second week of March 1999 or even 1989!!!  Change those tires!!!!

I just bought (Feb. 2009) a new set of Bridgestone Spitfire S11 tires.  Here is the code from the front tire.

Front tire date code

The last 4 digits are "4508".  This means the tire was manufactured the 45th week of 2008.  This works out to the first week of November, 2008.  This tire was not quite 4 months old when it was mounted on my motorcycle.

Here is the code from the rear tire.

Rear tire date code

The last 4 digits are "1908".  This means the tire was manufactured the 19th week of 2008.  This works out to be around the 2nd week of May 2008.  This tire was about 10 months old when it was mounted on my motorcycle.   Notice the balance mark above the date code.  This denotes the lightest spot on the tire and is usually placed next to the valve stem when mounting the tire on the wheel.

I would caution you to be wary of tires that have been sitting in a warehouse or on a shelf for too long.  If you buy a two year old tire and ride it for a couple of seasons, the rubber can start to deteriorate and become unsafe.

Here is an article on the American Motorcyclist website (the official website for the American Motorcycle Association) called "How to read a motorcycle tire".  For a listing of the D.O.T. tire plant codes, CLICK HERE.

Top of page Changing Tires

Here is my pictorial guides to rear wheel removal and 
front wheel/caliper removal.
Here is Mr. catbed's pictorial guide to changing front and rear tires.  

This is a thread in the Adventure Rider forum about using these lash straps from Harbor Freight to mount a tire on the wheel without using tire irons: http://www.advrider.com/forums/showthread.php?t=299597.  Basically, you use 8 lashing straps equally spaced around the tire.  Tighten them up until the bead is compressed toward the middle of the tire on the inside.  Then simply push the tire on the wheel with your hands.  Amazing!  The author's "tire dismount" procedure involves hack sawing the old tire off the rim using a piece of wood moulding near the rim so as not to damage it.

Use lash straps instead of tire irons

Top of page These are some thoughts from Mr. bwringer, of the GSR Forum,
concerning tire changing and tire vendors.

**********Paraphrased from Mr. bwringer**********

Changing Tires:
Here's the standard text on tire changing:
I would add that I simply use two large wooden clamps to break beads, which is a little slower but a lot safer (for you and your wheels) than the brute force methods shown here. I would also discourage the use of corrosive soapy water as lube -- a lifetime supply of real Ru-Glyde tire mounting lube is maybe $14 at NAPA auto parts. Use the Right Stuff.

Bead breaking and tire mounting lube are two areas which seem to attract an inordinate amount of homemade and potentially deadly hillbilly substitutes for doing it The Right Way.

Here are my absolute FAVORITE and time-tested sources for tires. There are a few other good suppliers and a whole bunch of bad ones out there on th' intarweb:

Excellent service and prices.

Located in Oregon. Ships quickly to the West Coast. Free shipping for orders over $75.

Great service, cheapest total cost (free shipping on sets of 2 tires). Slightly limited selection of oddball vintage sizes. They are located in Arizona, so tires take 3-4 days to get to the Midwest/East. They actually stock the tires they sell -- not just a middleman like most.

Huge selection, great service, total cost with shipping very low -- usually still within a few bucks of SW. Located in Ohio, so very fast shipping to Midwest and East. They also stock what they sell in a huge warehouse. They have a phone number you can call if you have a question or want to know if something is in stock. Hideous web site, but it works well.

DK stocks what they sell, has a huge selection, they ship the same day from Minnesota, and their site tells you how many are left in stock. Their tire pricing used to be completely outrageous, but it's now much better -- often the same or lower than others. Free shipping when your order goes over $100. Definitely worth checking, and great when you just gotta have your tires by a certain date.

These have been mentioned positively before, but keep in mind that they and most others are simply middlemen -- they do not stock tires. No way of knowing exactly when you'll get your tires, and in my experience, their pricing with shipping is not that great.

**********End Quote**********

Top of page And here are a couple of pictures of Mr. bwringer's high tech tire balancing apparatus:

Old jack stands, old Rollerblade bearings on topUse the spin method to find the heavy spots

That's right.  Just a couple of old jack stands with some old Rollerblade bearings used to spin the wheel, find the heavy spot, and clip on counter weights.  Mr. bwringer's pretty clever, isn't he?

Top of pageThese are the standard tire size conversion charts and code explanations for speed and load ratings:

Top of page

Rim Width/Tire Size Chart

You can download this as a a PDF file by using this link: Motorcycle Rim Width Tire Size Chart 

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