Tire Changing
by (?)

To all of those interested in changing their own tires,

To change your own tires, you'll need the following:

1. Two high quality tire irons in the 14 to 16 inch length range.They should have a curve at one end to clear the tire when you're trying to get it seated between the tire and the rim to get the tire off. These cost about CDN$14 each from my local dealer. Ask the dealer for ones like their service people use. There are cheaper (and shorter) ones available, but they're not worth it. The first time I did this, it was with some straight, 8 inch long tire irons borrowed from a friend, and it was far more difficult with the short, straight ones.

2. A couple of empty 2 litre (half gallon for you guys) ice cream containers. One will be used to put some soapy water in. The other will be cut up to make rim protectors, each about 6 inches long and 2 inches wide. There are also some commercially available rim protectors, but I've never seen them. They're called Rim Savers, and are supposed to be available through Parts Unlimited for about US$5 a pair.

3. A four foot length of construction grade 2 x 4 stud. The bead breaker will be made from this. Find a sturdy doorway or two solidly fixed objects close to ground level and measure the distance between them. Cut the 2 x 4 so that it's about the same length as the door opening is wide, and then cut this piece in half. Cut a 45 degree bevel on one end of each piece as shown in the sketch below.

____________ ____________
|___________/ \___________| 1-1/2"

4. Lead strips with an adhesive back. These areabout $2 and available at many hobby stores.

5. Remove the wheel/tire assembly from your bike and bring it to the doorway or fixed objects. Set it upright in the middle of the doorway and position the pieces of 2 x 4 so that the square end of each is in the bottom corners of the doorway and won't slide away if pushed forcefully. Lift the wheel/tire up about a foot andposition the beveled edges of the 2 x 4 against the tire just below the rim. MAKE SURE THE 2x 4s ARE ON THE TIRE AND NOT ON THE RIM. Otherwise, you might bend your rim. A helper to hold the wheel up or position the 2 x 4s is helpful for this part of the exercise. I've always done it on my own, but sometimes it feels like three hands are required. Once everything's properly positioned, push down on the tire. The 2 x 4s will push the tire in and off of the
bead as you repeat this exercise, working your way around the tire.

6. Once the bead has been separated from the rim, use the tire irons to lever the tire over the rim. First, lubricate the tire with soapy water on a paint brush. Put the rim guards between the rim and the tire irons when inserting the irons. Things will go easier if you can get the bead to seat in the depression in the middle of the rim while levering the opposite side of the tire over the edge of the rim. Be generous with the soapy water, as it makes
things go easier as well.

7. Once the old tire is off, inspect the rim for damage and bits that may have gotten themselves stuck between the rim and tire. Clean these away. Make sure that the rim is clean before mounting the new tire. Also inspect the new tire, particularly around the bead for rubber spurs, labels and bits of packing materials. Make sure that there's nothing inside the tire as well. Look for a balance mark on the tire. Different manufacturers use different marks. Dunlop uses a yellow ring, Bridgestone a yellow dot and Michelin uses no mark of any kind. I think Metzeler has a white
ring (not sure), but it should be clear if you have the tire in hand (unless it's a Michelin). Turn the tire so that the direction arrows on the tire match the direction the wheel will turn when on the bike. Position the balance mark on the tire so that it lines up with the air valve on the rim. After lightly lubricating the bead with soapy water, start to push the tire on to the rim by hand. Once you've gone as far as you can, get the tire irons and rim guards out again and finish the job off. Be carefull not to lose the rim guards in the tire. Be liberal with the soapy water, particularly as you do the last third of the second bead and take your time, as this is the hardest bit.

8. Once the tire is on the rim, wip away any excess soapy water and add air. It could take up to 75 psi to get the bead to seat. The air supply at a service station may be better for this (higher flow capacity) than the little compressors that plug into the cigarette lighter of your car, particularly if there's some leakage before the bead seats fully. Do not do anything stupid, like placing a finger or other object between the tire bead and the rim before it seats while adding air, unless you want it crushed and trapped. The beads will seat with a loud ping when the bead snaps into place. Once seated, bleed off the excess pressure to the recommended operating pressures. Then it's time to check that they've seated properly. There should be a circumferential mould line on the tire just above the edge of the rim. This should be the same distance away from the edge of the rim all the way around on both sides.

9. For balancing, I do a static balance. If it's good enough for the Dunlop people to use at Daytona, it should be good enough for me. I have an 8 foot long metal saw guide that breaks down into two four foot pieces (CDN$22). I stand these on edge between a work bench and another support, being careful to make them level along their length and from one to the other. Leaving enough space for the wheel, I clamp the metal guides together I then install the wheel's axle and put the wheel between the metal guides, so that the axle is supported by the guides. Gently spin the wheel and mark where the high point is when it stops. Repeat several times. An average of the points should give you the location for where any wheel weights should be added. I then use a piece of the lead strips and cut a piece off that I know will be too big. Bend it to fit the contour of the wheel and tape it in place with a minimal amount of transparent tape. Do not use the adhesive backing yet. Spin the wheel again, noting where the new high point is. Gradually trim the lead weight until the stop points are completely random. Once the stop points are random, secure the weight with the adhesive backing. Make sure that the rim is free of any residual chain lube, dead bugs, adhesive from the old weight, etc before fixing the new weight in place. My F2 has a rib in the centre of the rim, and I like to place the weight hard up against this to help protect it and stabilize it. If you want some additional security, put a piece of racing tape (aka duct tape) over the weight as well, but make sure you balance the wheel with a similarly sized piece of tape in the immediate neighbourhood of the weight.

10. Remount the wheel on the bike and recheck the pressure to make sure it's where it should be. If you're not sure, look at the sticker on your bike's swing arm, post it to the list or talk to one of the tire companies' tech reps.

Much of this is based on an article in the December 1995 issue of Sport Rider, and adapted to fit the tools I made for myself. If I remember correctly, their tire balance stand cost over US$100 and the bead breaker was about US$50. You can decide whether it's worth it for you to buy these things or make them yourself. Forme, it wasn't, because I had some reasonable alternatives at hand. Also, this is one of the ultimates in assuming responsibility for your actions. Comressed air can be dangerous to deal with, and an improperly mounted tire can cause you to crash. ALWAYS remember that it's your life that depends on how well you do this. Good luck, and I hope this helps.


Disclaimer: This information has been been reviewed and, where possible, verified. We are not, however, responsible for any mistakes or omissions that have slipped past us. When in doubt, seek official verification.


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