Mounting and Balancing Motorcycle Tires


Date: Mon, 6 May 1996 23:06:54 -0400 (EDT)
Original-From: rider@pullman.com (Bill Johns)
Subject: mounting tires

Thoughts on the fine art of changing your own tires.

Tools.

Remove wheel from bike.

Break bead.

This can be easy or difficult as you wish. The really difficult way is to jump up and down and swear a lot. It doesn't work and gets you very frustrated. The very difficult why that works is to buy a bead breaker. Looks like a big C-clamp and you must use a wrench to turn a threaded shaft against the bead for about 3-4 inches each side. Time consuming and hard on the wrist.

The fast way to break a bead is to make a bead breaker. Two 2x4's and a couple of hinges.
[bead breaker GIF]
(drawing by Brian Divers)

       wall
        |
        |
        |_A_____________________B__________P
        |                       |
        |                       |
        |                       |
        |                       |
        |                       |
        |                       | c
        |
        |                       X

Fasten to a wall, at point A, a hinge attached to a 2x4 that is about 3 feet long. At point B attach another hinged 2x4 which has point c sharpened to a 0.5 x 1 inch (very blunt) point. Put wheel at X using scraps of wood so that you don't grind a disk into concrete or anything dumb like that. I balance the whole wheel on a couple of strategically located 4x4's. Put the dull point on the tire right next to the bead and push at P. Can do the whole wheel, both sides, in about 30 seconds. My drawing is a little out of proportion The section from A to B is about half of the 3 foot length. If you are clever, you will mount the hinges so they will fold away flat against the wall when not in use.

Having loosened the bead from the rim, you must now remove the tire.

This is the hard part. I use scrap rubber from an old truck inner tube to keep from scratching the metal. You must work the old bead over the rim and then off the tire with the tire irons. Soapy water helps a bunch. Wear leather work gloves as you will pinch your hands and scream and shout and carry on if you do not. You will probably scream and shout and curse in any case. Kids from the neighborhood would all come over just to listen to me do this part of the operation.

Remounting the new tire is just the reverse of the old tire removal.

Make sure that you line up a dot with the valve stem at this point (Michelin's don't have a dot as they are so perfectly made (they claim) that they don't need it. In fact they are. I've mounted them and not had to balance them. Only tire ever that didn't need weights.) Make sure you have the tire going in the proper rotation with the wheel.

Once the new tire is on the rim and the little arrows are all pointing the correct position, it is time to reset the bead.

Remove the valve stem. Air goes in faster if the valve stem is out and you need to get air in rapidly. Go to a gas station and put air in the tire. About 80% of the time air will go in and with a little minimalistic massage of the tire the bead will pop on with a lot POP! About 18% of the time you will get most of the bead to seat but a small section will not. Put the valve stem back in and bounce the tire near the section that will not seat. It will eventually. Some folks say you shouldn't run a tire over 50 psi while attempting to seat the bead. I've gone a little over that and only had 4 tires blow up so I dunno if that's a fair statement. ;-) Only once did I have a tire that would not seat. Took it to a tire changing place and the fellow there with all the neat tools and belts and such took 20 minutes. Life happens.

Put the valve stem in and put the tire to working pressure.

Relax, the hard part is over.

Balance tires.

I use a couple of metal folding step stools I got at Costco. They are nice in that they have a section of round metal tubing along the back that is straight. Any stands or saw horses or whatever that have metal edges or tubes on them will work. Find a spot on the floor that is flat and with the two stools back-to-back and about as far apart as your axle is long less 1.5-2 inches make sure the two support surfaces are level in all directions.

Remove all old weights. WD-40 helps.

Put the axle in the wheel, wipe off all excess grease and mount the axle on the stool backs. Let the wheel find its own level. Mark the bottom. Rotate and confirm that the bottom is the heavy side. Go 180 degrees away and temporarily tape a small weight. Recheck the balance. Adjust. Recheck. Reiterate until the tire will stay balanced in _any_ position.

(This method of balancing is better than machine balancing and is in fact what racers do. Machine balancing is faster, not better.)

Once the wheel is balanced, secure the weights (they come with a strong foam rubber two-sided glue), remount the wheel. Test to a minimum of 135 mph.

I use to do all my own tires. Took about 45 minutes total once you get the hang of it. I now have a local shop that will mount and balance mail order tires for $10 a pop. If it went up to $20 per, I'd go back to doing them myself.

Ride Free,

Bill

-------
rider@pullman.com or w_johns@wsu.edu

DoD #00314  KotV, KotRR
FJ1200, KLR 650 & a Yam 650 Special in parts.

updated 1997/01/24

WetLeather is a trademark of Carl Paukstis
carlp@micapeak.com