Home. Back. ...... The Gas Gas Guru. Technical Information.

By Jon Stoodley

Let’s talk about changing tires, an activity that most riders rate up there with oral surgery and doing taxes. Tire changing techniques are a “personal” thing, like the “right” way to load a motorcycle in a truck, everybody has their own set of habits developed over time. The techniques here are not the only way but just some of the tricks I’ve found that have helped me.

First, having good tools is important. The best set of tireirons I’ve found are the forged, 15 inch set with one of the ends formed a slightly bent shape. I modify them by narrowing and thinning the tips and polishing them. This allows the tip to slide easily and not damage the bead, tube or rim. A 5 gallon bucket makes a good holder for the tire assembly when working on it as it will keep the tire out of the dirt and doubles as a good container for other things when not in use. It can be filled with rocks or dirt to hold it steady when working on the tire. A valve core remover type cap sealed with Locktite to a automotive tubeless valve stem makes a good valve core remover that is easy to handle and won’t get lost in the toolbox. A squirtbottle of soap solution works great as a bead lubricant. Store the new tire with corrugated cardboard inserts forcing the bead wide apart. This will make it a lot easier to mount the tire and seal the bead on tubeless tires after they are mounted.

I’m often asked if tube-type tires can be mounted on tubeless rims and the answer is yes- but. You will have to drill the rim to install rimlocks and the “safety rib” (that rib on the inside of the rim designed to keep the bead on) will make installing a tube a major hassle. Mounting a tube and tube-type tire on a tubeless rim defeats the advantages of the tubeless design and it’s probably better to fix the leaking rim.

When changing tires the first step is to make sure the whole assembly is really clean. Dirt and grit will only cause problems. When putting the rim on the bucket, lay it sprocket side down. This will keep you from needing skin grafts later. Breaking the bead down is the next step after deflation. Tubeless tires can be a real chore due to the aforementioned “safety rib” holding the bead to the outside of the rim. Pull the bead down with the tireiron and squirt soap solution down into the bead area and let it soak in. It’s hard to use too much soap solution. The bead can probably be levered off, with much effort. I’ve seen riders place the tire on the ground and push the bead down with the heel of their boots. I’ve also heard of several VERY creative ways to break down tubeless beads, however, it would probably not be prudent for me to mention them here.

There are several commercial bead breakers available and I think Motion Pro (who make some really neat tools for bikes) and Tucker-Rocky carry them. I’ve also used hydraulic and arbor presses with good results. Several years ago I made a portable bead breaker to take to the races out of a simple pipe clamp (see photo)and it works really well for me.

After breaking both beads down, force the bead on the side of the tire you are removing to the center of the rim (low part).otherwise the tire will be extremely difficult to get off. Using lots of soap solution, start levering off the opposite side by using one iron to pull up and hold the bead. The other iron is then used to pull up small amounts (maybe 2 or 3 inches at a time) rather than big chunks that could damage the tire bead.

This is probably a good point to give a tip that may change your life when removing and installing tube-type tires. The absolute best way to avoid pinching tubes is to not pull the tireiron past the straight up point. That is, when the tireiron is pulled up to the 90 degree point, in relation to the hub/rim assembly, don’t pull further in towards the hub. Giving the iron that last bit of pull past the straight up point is what pinches tubes against the inside of the rim. To disengage the lever after it is at the straight up point, push it sideways towards the unlevered part of the tire in a forward rowing motion. This is hard to describe but once you get the hang of it, it will be easy. The iron will then just pop out (providing it is polished) leaving that part of the bead above/below the rim and the tube undamaged.

In preparation for assembly, thoroughly clean the rim, tire and tube if necessary. Make sure the tire is warm and therefore pliable. On tube type rims, I discard the rubber band and wrap about three layers of thin duct tape on the center of the rim. Don’t forget to cut holes for the rimlocks and tube stem.

Here comes the fun part, assembly. Lube the tube and inside of the tube-type tire with talcum powder to allow the tube to assume a round shape when inflated and not get pinched. Using lots of soap solution, start levering the first bead on the tire on by using the “hooked” part of the tireiron which will reach down inside the tire better. This is probably the only time I use that end of the tireiron.

For tube-type tires I like to install the tube first and then the rimlocks last. Put a nut on the tube stem and the rimlocks now, but only about 4 threads down. This will keep them from being sucked into the hole during assembly. I try to push the tube down inside the tire as much as possible before levering on the last bead. Having a little air in the tube to make it round will also help to prevent pinching.

Use lots of soap solution to lever the last bead on. Remember, small “bites” and tireiron not past the straight up point for tube-type tires. When near the tube stem or rimlock, push on the stem/bolt so they stay up inside the tire and don’t get pinched by the bead. After the bead is on, for tube-types, push the tube stem and rimlock bolt in to release them from under the beads inside, where they often get bunched up during assembly. Make sure the valve stem is coming out of the rim at a 90 degree angle and is not cocked to either side.

At this point, the tire can be inflated to about 20 to 30 PSI to seat the bead. If the rim and tire was clean and lots of soap solution used, it shouldn’t take a lot of pressure. Be sure to keep fingers and face away from the tire when seating the bead. On the tube-type, the nut can be tightened just enough to get the inflater nozzle on. I use a blowgun type attachment with the pin that presses on the valve core removed and the whole assembly is “ported” to allow a lot of air to flow through. It has a latch type nozzle so it can be used with one hand. This works really well for tubeless tires that have the safety-rib rim as you need to get a lot of air in a hurry into the tire to spread the beads. There are commercial bead spreaders available or a rope or tiedown can be wrapped around the tire and then tightened by inserting a tireiron and twisting. You have to be extremely careful though, as the expanding tire might spin the iron out of your hand and cause injury. As I’ve had to change a ton of tires (including the notorious Trelleborg and Barum monsters) and want to make things as easy as possible for myself, I made a bead spreader from a length of bicycle chain using a screw type arrangement to tighten. After the bead is seated, deflate the tire, install the valve core and reinflate.

For tube-type tires, snug down the rimlocks but do not overtighten as this can push the bead away from the rim and make the tire spin on the rim. I like to leave the nut off the tube stem as this way I can keep track of tire slippage on the rim. The stem will be at an angle if the tire is loose. Always keep good valve caps on the stems as this will keep dirt out of the core. When I’m not riding the bike, I store it with about 15 to 20 PSI in the tires, which keep them in better shape and I only have to let out air to the desired pressure.

Professional tuner and 'Trials Competition' writer Jon Stoodley has very kindly stepped up to the plate to answer your questions. If you're having problems, or need some advice just send an email to Jon. If it's something that could be useful to others, we'll post it on the site.
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