Feets Don't Fail Me Now

story by Martin Hackworth, Created May. 24, 2004
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A Guide to Changing Your Own Motorcycle Tires

Changing tires on a motorcycle is one of the few standard items of maintenance I'd recommend that any rider attempt for themselves. Of course, you'll need a reasonably well-equipped workspace, but anyone who wants to save a little time and money should be able to accomplish a tire-swap in an evening. It's absurdly easy to find screaming deals on mail order tires from any number of vendors these days and you can get them shipped inexpensively to just about anywhere in North America lickety split. If you are fortunate enough to live in an area where well-stocked motorcycle shops abound, I'm sure that it's possible to get same-day service on tire mounting and balancing. For the rest of us, purchasing new tires often requires leaving a bike at a shop for a few days. As often as I go through tires, this involves considerable down time. Since I can have a set of tires changed in about 90 minutes all by myself, and save money in the process, it makes sense for me to do it myself. It might make sense for you as well.

As it happens, do-it-yourself mounting and balancing, is a task well within reach of most reasonably competent weekend mechanics. An unexpected bonus that I've discovered is that I tend to get much better wear out of tires that I mount myself -- probably because I'm more careful about getting them balanced properly than the kid (who's other job is usually sweeping the floor) doing tire changes down at the corner shop. Changing tires is a project I'm confident that the average MO reader can not only do for themselves, but also do a pretty darned good job of. If you'll give it a try, I think you'll pull it off.

 


Having said that, the normal proviso for all do-it-yourself endeavors applies, i.e., If you are illiterate, suffer from acute ADHD, smoke crack, are unable to exercise a modicum of good judgment, or are just plain dumber than a fence post, you might want to consider entertaining yourself back in the "Babes of Bike Week" section at MO. Mounting tires can be dangerous. Seating the bead (continuous steel wires inside the edges of a tire designed to secure it to the rim) on a new tire, involves rapid pressurization to pop the beads onto the rim seats. If you get too carried away, you can easily give yourself a brand new crushed finger. Even something with a small volume of relatively low-pressure compressed air, will make an amazing boom should it rupture while you are working on it. I'll never get over the time (back in May '79) that an automobile tire I was working on at a gas station in Driggs, Idaho exploded and knocked me backwards into a stack of oilcans that fell on me just like in the movies. This still gives me the heebee jeebies and it barely begins to explain the potential hazards of do-it-yourself tire mounting. Eyes, ears and fingers are all at risk. Please exercise appropriate caution and be sure to wear safety glasses at all times. The directions below apply specifically to tire changing on modern street bikes. Dirtbike tires are an order of magnitude more difficult to get on and off their rims and I'll address them separately in a later article.

You'll need a work area with enough room to move around in and enough space to bolt a tire-changing stand to the floor where you can get completely around it. While it is possible to build your own stand, Harbor Freight sells a really

   
   Tools of the trade.   
nice motorcycle tire-changing stand (#42927) that bolts to their standard automotive manual tire changer (#34542). The total cost for both items is low; around $60 on sale (sales are the norm at Harbor Freight) and this setup is well worth the cost. (In fact, it's da bomb, easily the best invention since low-carb huckleberry smoothies.) More about this stand later. The hand tools required are: two tire irons, a spray bottle with soapy water (any dishwashing liquid in water works just fine), a brush, gaffer or duct tape, a valve tool, a rubber mallet, wrenches and/or sockets to fit your particular bike, an air pressure gauge, an air tank (preferably attached to a compressor) and safety glasses. Like picking-up a woman in Tijuana, a buddy comes in handy, especially if it's your first time.

The bike shown in the accompanying photos is a CBR954RR that is in the final stages of being converted back to street duty, after a weekend at the track. The CBR is fairly typical of most modern sportbikes. Your bike will probably not be race wired or equipped with abused DOT legal race tires, but other than that, everything else ought to appear pretty much the way that it does in these photos.

Let's get started: First, you must securely support your bike with the wheels raised off the ground. If your motorcycle is equipped with a center stand you're set for rear wheel removal, but you'll still have to raise and support the front. Since many modern sportbikes don't have centerstands, the easiest and least expensive way to raise both ends of most bikes will be with a combination of a front wheel stand and a rear swingarm stand. Note: many stands, which purport to be "universal", will not work with all bikes no matter how adjustable they are. Before purchasing stands you should be sure to check for compatibility with the bike(s) that you intend to use them on. My shop is equipped with an overhead electric hoist that makes funky situations (like the asymmetric R6 front end on my FZR) a lot easier to deal with. I just use a little nylon webbing and hoist the bike by either the top triple clamp or the frame spars just aft of the middle of the bike (I'm pretty sure that using the rear sub frame for this purpose is not a great idea). If your bike is equipped with bosses for swingarm spools, I highly recommend spool stands, which are the ultimate combination of speed/security in swingarm lifts.

I'm going to begin with the rear wheel. As a rule of thumb, the wider the tire is the easier it is to break and re-seat the bead, so it's a good place for us to begin. After you've made sure that the bike is securely supported the next step is to make careful note of the arrangement of bushings, washers alignment collars and nuts on the rear axle and swingarm.

Once you've figured out how everything goes together (make notes if you have to), you can remove the retaining pin from the axle nut and remove the nut itself (Fig. 1). Not all axle nuts have a retaining pin so don't worry if you don't see one on yours. Unless it's been previously over-torqued, the axle nut should come off without a lot of muscle.

   
   Fig. 1 - Though we don't condone using crescent wrenches on your bike, they will work in a pinch.   
I find it very useful to make sure that the rear wheel is supported at this point, as it makes it much easier to convince the axle to slide out, when the wheel isn't pushing-down on it with 20Lbs of force. I make sure to clean the axle very thoroughly every time I take it out and give it a light coat of waterproof grease before replacing it at the end of the process. Be sure to be very gentle while tapping the threaded side of the axle when you remove it (use a rubber mallet or a block of wood against the threads). On most bikes, the rear brake caliper will come off as you tap the axle out and you will want to be especially diligent in noting the position of washers and bushings associated with it.

Once the axle is out and you've carefully inventoried all of the hardware and noted where everything is going to go upon reassembly, you are ready to remove the rear wheel from the swingarm. Most modern chain driven sport bikes are equipped with a rubber "cush drive" for smoother operation. If your bike is so equipped, the sprocket should separate from the hub with just a firm tug. Be sure to make note of how the rubber cush drive bushings fit in the hub. The exact location of each isn't really important, just how they are oriented in their slots. Place these aside with the sprocket. You are now ready to begin removing the tire.

   
   Fig. 2 - After letting most of the air out, use a valve-stem tool to remove the valve-stem from the tire valve.   
Tire removal begins with getting the air out of the tire. Virtually all modern sportbike tires are tubeless, which makes the process a lot easier than it used to be. You want to remove the valve cap and valve stem from the rim. Use the pointed end of the valve tool to let the air out of the tire. When this is done use the slotted end of the valve tool to unscrew the valve stem. In the process of unscrewing the valve stem (Fig. 2), the remaining air will vent and you want to be careful not to shoot the valve stem across the room in the process. It is also a good idea to note the amount of torque (not much) required to loosen the valve stem. When the air is completely out of the tire, make sure to make note of the direction of tire rotation (there will be an arrow on the tire sidewall noting the direction of forward rotation) with respect to the rim. On the rear wheel the direction of rotation is obvious because of the asymmetry in the hub. All you have to do with the rear is put on the new tire with the arrow pointing forward. But I use masking tape and a sharpie to mark the direction of rotation on the front rim, before I remove the tire.

   
   This handy tire-changing stand is available from Harbor Freight for about $60.   

If you use the Harbor Freight stand (which I highly recommend), this is what the fully assembled unit will look like. Astute observers will note that the pre-assembled clamps on this stand were put on backwards. It was a simple matter to fix this, but if you buy one of these and can't figure out how the edge of the rim is supposed to fit onto the clamps, that's the reason why. Be sure to bolt the stand to the floor of your work area. Using this particular stand in freestanding mode is tantamount to committing brake rotor hari-kari. The correctly assembled stand looks like this. I normally use a few layers of gaff tape on the clamps to protect the rims from scratches.

Before the tire and wheel can be mounted to the stand, you must first break the tire's bead loose from the rim seat. The lower part of the Harbor Freight stand has an attached bead breaker that works very well (Fig. 3). I've seen all sorts of homemade presses and levers used for this purpose but an advantage of the Harbor Freight stand is that it comes with a very compact bead breaker that is almost worth the cost of the entire outfit by itself. I use a piece of soft wood to cover the metal leg of the stand where the wheel is going to contact it. Place the tire on the ground below the bead breaker's shoe (as shown below). Be extremely careful not to allow the brake rotor(s) to touch anything. Putting any substantial lateral force on brake rotors will warp them. Do this and you'll rue the day you considered changing tires yourself as an economical move.

   
   Fig. 3 - The lower part of the Harbor Freight stand has an attached bead breaker that works very well   
Bead-breaking can get tricky (Fig. 3). Most sportbike tire beads, especially on rear tires, will break from their seat with a small amount of soapy water and very gentle persuasion with the bead tool. Some tire/rim combinations (Michelin Pilot Sports on Honda sportbike rims come to mind) will pop so easily that you'd swear that you could have done it with your fingers. In general the narrower the rim the more difficult it is to unseat the bead, but most street bike tires will come off with very little effort. Dirt bike tires are a different story. I have found that properly fitted Dunlop tires will tenaciously grip the rims of my XR600R to the extent that even my favorite mini-gorilla, MO's own Ebass, toting a 10' cheater pipe and with Sean's mass tied around his waist would have a hard time breaking the bead.

Once you succeed in popping the upper bead from the rim seat, rotate the tire and do it again until the entire upper bead is free. Flip the wheel over and repeat for the other side. Once you have the bead completely free on both sides of the tire, you are ready to mount the rim on the upper part of the stand (Fig. 4).

   
   Fig. 4 - Once you have the bead completely free on both sides of the tire, you are ready to mount the rim on the upper part of the stand.   
Be sure to tighten the clamps so that they hold the rim firmly, but do not over tighten! I also consider it good policy to use the safety rods supplied with the stand to prevent the rim from completely parting company with the stand should it slip out of the clamps. This is easier to accomplish that you might think and a rim dropped on your toe, will absolutely put a damper on your tire changing adventure.

Now it's time to break out the tire irons. You are entering a new and potentially catastrophic phase of the tire-changing process, so pay attention. What ever you do, do not use large automotive tire irons to remove a motorcycle tire. Use the short motorcycle tire irons sold and nearly every motorcycle shop on the planet. If you care at all about the condition of your rims, the shorter the better. My tire irons are about 10" long (Sure they are... -Sean). If you are doing things properly you won't need much leverage from the irons to remove most tires. Some street bike tires can almost be removed with bare hands, if you know how to do it. Simian strength and huge leverage are superfluous and dangerously counterproductive in this process. If you have to use a large iron or a crowbar you are most likely doing something wrong. Motorcycle rims are quite strong longitudinally, but will withstand very little lateral force along their edges before bending. Tweaking your rim is the third way to prematurely end your tire changing adventure. You must also exercise extreme care not to bend the brake rotors by pressing against them with your tire irons. Rear brake rotors are typically small and easy to avoid, but using a curved tire irons will help you to stay clear of fragile parts.

   
   Fig. 5 - There are two tricks to getting the tire off the rim, without a lot of muscle. The first is to use soapy water.   
There are two tricks to getting the tire off the rim, without a lot of muscle. The first is to use soapy water (Fig. 5). The second is to make sure that the tire bead is not touching the rim seat or the edge of the rim anywhere on either side of the tire. Since the rim is deeper in the center, than it is at the edge where the tire seats, you'll be able to get the bead started over the outside of the rim fairly easy, if you first force the sides of the tire to the center of the rim in the area opposite from where you are going to begin with the tire irons.

I use gaff tape to protect the rims in the area where I am going to begin with the tire irons. Some people use cut up plastic shampoo bottles or milk jugs for the same purpose. You can also buy rim protectors or rubber coated tire irons from your local motorcycle shop. Normally, it's not necessary to protect more than 1/3 of the rim's circumference in the vicinity of where you are beginning, because once you've got a third of the tire over the rim, the rest comes off without much leverage. Once you've got a single iron inserted between the tire and rim as shown (Fig. 6) (make sure to use the dished end of the iron to hook the

   
   Fig. 6 - When you've got a single iron inserted between the tire and rim, use it to lever the bead up and over the outside of the rim.   
tire bead), use it to lever the bead up and over the outside of the rim. Hold this iron in place then insert the second iron between the tire and rim a few inches from the first and again lever the bead up and over the outside of the rim. This process is a lot easier if you've force both beads on the opposite side of the tire to the center of the rim. If you do this the bead should come up and over with very little effort. Getting the tire completely off, basically involves repeating this process, moving the irons a little farther apart each time, until a big portion of the bead pops over the outside of the rim. Again, surprisingly little force is required if you are doing this properly. If you are straining every muscle in your upper body trying to get the bead over the rim you are either doing something wrong or are an 8-year old girl.

   
   Fig. 7 - Once you get the bead on the upper side of the tire completely over the edge of the rim, the opposite (lower) side should come off using just your hands.   
Once you get the bead on the upper side of the tire completely over the edge of the rim, the opposite (lower) side should come off using just your hands (Fig. 7). Again, the secret is to force the bead on the opposite side of the tire from where you intend to begin to the center of the rim. Do that and the tire should easily come off with very little effort.

   
   Fig. 8 - Once the old tire is off, you will want to carefully inspect the seat and the edge of the rim.   
Once the old tire is off, you will want to carefully inspect the seat and the edge of the rim (Fig. 8). Clean dirt and debris from the seat, clean up any water, oil or grease anywhere inside of the rim and carefully inspect the entire rim before mounting the new tire.

Putting the new tire on is relatively easy and basically involves reversing the previous steps. Make sure to observe the direction of the rotation arrow on the tire and to place the tire on the rim in the proper orientation. Again the lower bead should go on easily with just your hands and a little soapy water. When mounting tires you want to be as sparing as possible with the use of soapy water, since you don't want a lot of it trapped inside the tire after you're done.

Once you get the lower bead over the top edge of the rim, you'll want to line-up the harmonic balancing mark with the valve stem. Most (though not all) tires will have a paint mark somewhere on the sidewall that marks the lightest part of the tire. Since the heaviest part of the rim is, ostensibly at least, the area containing the valve stem, the idea is to line up this the lightest part of the tire with the heaviest part of the rim. Lining-up this paint mark with the valve stem, should help to achieve a rough balance. I usually verify that the valve stem is in fact the heaviest part of the rim on my balancing stand before mounting the new tire but I haven't been let down yet. I have however, on rare occasions, encountered paint marks that were located near the heaviest part of the tire. Unfortunately, you won't discover this until after the tire is mounted. At this point, fuming, cursing and swearing vengeance against the manufacturer, while not particularly effective, are about the extent of your options, other than re-doing the steps above.

The upper bead will require the use of tire irons once you have it about half way over the rim. Again, use the soapy water sparingly and be very careful not to tweak your brake rotors! A little patience and more finesse will go a long way. Again, if you are straining like a banshee, you are probably doing something wrong.

   
   Fig. 9 - With the valve stem still removed, inflate the tire, until you hear a couple of loud pops as the beads seat.   
Once the tire is completely on the rim, it's time to seat the beads. You must exercise extreme caution in this step of the process. I like to use and air compressor for this step (as opposed to an air tank) because it allows the use of a large volume of air while still limiting maximum pressure. The idea here is to get the air into the tire fast, not to bomb it up to 80psi. I usually set the regulator for a maximum pressure of 45 - 50psi and see if that does the trick (it almost always does). If it doesn't work, you'll have to repeat this step until it does, but use extreme caution with higher pressures.

With the valve stem still removed, inflate the tire (Fig. 9) until you hear a couple of loud pops as the beads seat. Usually these "pops" are loud and quite unmistakable, but occasionally the beads will seat without a pop. At any rate, listen for air leaking around the edge of the rim before removing the pneumatic fitting from the valve. Once you are convinced there are no leaks disconnect the fitting from the valve and allow the tire to deflate. Once the air is completely out screw the valve stem back in and inflate the tire to the pressure recommended on the sidewall. If you are changing both tires, now is a good time to place the rear aside and concentrate on the front.

   
   Fig. 10 - A pair of pinch bolts is commonly used to bind the front axle in each fork leg and these must be loosened prior to removing the axle itself.   
Removal of the front wheel on most modern sport bikes involves some additional complexity. First, a pair of pinch bolts is commonly used to bind the front axle in each fork leg and these must be loosened (Fig. 10) prior to removing the axle itself. On dirtbikes and cruisers, brake caliper interference isn't usually an issue. However, on 17" rims, you will probably have to remove both front brake calipers, in order to get sufficient rim clearance for wheel removal (Fig. 11). Unlike the rear caliper, these are typically secured to the fork legs with two bolts that must be removed. Once the front wheel is removed from the bike, the tire removal process is identical to that of the rear. Since front rims are usually narrower, the front tire is usually a little harder to get off the rim. However, if you picked up on the right tricks with the rear, you shouldn't have a real problem. It is important to note that front brake rotors are bigger and easier to damage than rears. Again use extreme caution.

   
   Fig. 11 - On 17" rims, you will probably have to remove both front brake calipers, in order to get sufficient rim clearance for wheel removal.   
Once you've got both tires on their rims and have inflated them to proper operating pressures, it's time for balancing. Proper balancing will result in enhanced tire life and a much smoother ride. The only tools required for tire balancing, are a stand (mine is made from 2" x 4"s) that will accept a metal dowel over which you can slide the axle for your wheels and a pair of pliers to trim the wheel weights. Everything needs to be level and the wheels must be able to turn freely on your stand, but that's about it. I also find it helpful to have the wheel closer to eye level than most bench top stands, but that is a matter of personal preference. Before I begin balancing, I take the opportunity to dress up any small nicks or scratches on the rim, with a little touch up paint.

   
   Fig. 12 - When balancing, the basic idea is to determine where the wheel is heaviest, by allowing it to rotate freely and checking to see if the same spot consistently settles to the bottom.   
When balancing, the basic idea is to determine where the wheel is heaviest, by allowing it to rotate freely and checking to see if the same spot consistently settles to the bottom (Fig. 12). If it does, you add wheel weights to the opposite side of the rim until the wheel is balanced, i.e., it does not settle in any one place after you spin it. I like the weights with the adhesive on the back. Just trim the weights until you have the proper amount to achieve a good balance and viola, you're done. When I've got the wheel balanced, I put a layer of gaff tape over everything for extra security and to camouflage the silver weight on my black wheels.

The final step is to put the wheels back on your bike. If you were careful in noting how everything came off, this should not be a problem. It's also a good time to check chain and sprocket wear and replace if necessary. Make sure to tighten all bolts to the proper torque specs, line up your rear wheel with the indicator marks near the axle and set the drive chain tension according to your owner's manual. I also like to take this opportunity to do a careful inspection of the entire drive train and foot controls. Some folks like to do a front and rear wheel alignment at this point, but my girlfriend has the shakes and the laser pointer always gets me in the eye.

That's about it. The first time around you should budget a couple of hours for all of this, but after a while, you'll be enough of an old hand, that you can do it much faster. Once you hit the road, be careful to take it easy on fresh tires as they are very slippery until scrubbed-in. Highsiding a bike on fresh tires is an embarrassingly common occurrence, even among those of us who should know better. Also, your brakes will need a few pumps to bring them back up to operating pressure, so it'd be a good idea to do this before going for a big old stoppie at your first intersection.



Tire sidewall information. Service specifications.
   

The numeric codes or service specs on the sides of your motorcycle tires are something that you'll need to know and understand, before ordering a new set of rubber on your own. Even though in the normal course of events, you'll probably order replacement tires similar to the ones that are currently on your bike, it's still smart to understand your tire's specs. Aside from proper suspension setup, tires are the most critical factor in determining the handling of your motorcycle. All racers know this and anyone who follows racing, is aware of how subtle changes in tire compound influence adhesion and wear. What you may not know, is how aspect ratio and tire profile can also have a significant effect on motorcycle handling. Got a slow steering bike? Try a more triangular front tire. Dragging hard parts in corners? Try a higher profile rear tire. Before you drop 2K on that spendy shock and forks, you might do yourself a huge favor (and save some serious bank) by simply experimenting with a new set of tires.

When it's time to purchase new tires you can retrieve the proper tire codes from either your old tires, or by looking up the recommendations in your service manual. If the tires on your bike are OEM and you are happy with the way they work, just get the tire codes from them. Bear in mind that OEM spec tires are frequently compounded differently than the same, non-OEM tire. If you want the exact tires that came on your bike from the factory, be sure to order the OEM variants and expect to pay a bit more for them.

A few twists and turns aside, this is how to interpret tire specs. This first photo shows the new rear tire I mounted on the bike. The code embossed on the side of the tire is "190/50 ZR 17 MC". This refers to a width of 190 mm, an aspect ratio of 50%, a speed rating of Z (rated for continuous use at speeds exceeding 150 mph), the R is for Radial construction, the 17 refers the diameter of rim the tire is designed for, and MC simply means that it's a motorcycle tire. Speed ratings are based on European ECE 30 Indoor Wheel Test Standards, which go all the way from A to Z. MC speed designations usually go from S rated tires which are good up to 112 mph, through Z rated tires that are good for 150 mph+.

Here is where a little knowledge is sometimes a bad thing. Many squids are enamored with the super wide look of 180, 190 and even 200 section rear tires. While it may be tempting to spoon on the widest tire that will fit on a given rim, you should bear in mind that this changes the aspect ratio of tires (percentage of height to width) in a way that often produces less adhesion at high lean angles. Tires wider than OEM's may also cause clearance problems. Most racers actually mount the narrowest tires that they can on their rims for better adhesion at high lean angles, less rear wheel steering and better aspect ratio for ground clearance.

   
You can also tell the age of motorcycle tires and hence their shelf life, by checking the date code embossed on the tire. Date code formats vary but for modern sportbike tires the code should look like the one in the photo below (i.e., 0502). This tire (the OEM that came with the bike) was built in the 5th week of 2002. This is a very useful piece of information, as most tire compounds tend to become less pliable and compliant with age. If you like grip, avoid older tires.

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