BMW motorcycle tire removal and rim ding repair
I have mounted hundreds of tires on BMWs, but they were all the older models with spokes. So far, I only have one wheel available to show for removal, but it is typical, and the same procedure applies to many years of BMW.
I like to find a clean place to work and a piece of carpet for a soft working surface. The carpet helps protect the rim. I cleaned up the rim to make the job a bit less unpleasant. It was really dirty, and that was my “first” alarm signal.
Inspection shows that this tire was ridden for too many miles. It is nearly down to cords. My “Second” alarm signal.
Some examples of tire irons. The top one was made in the USA and is longer, but fatter and thicker. I don’t like them. The middle is a Dowidat model 38-8, and I love them. They are thin and strong. The lower one is out of the BMW tool kit. They will work, but are short and not as thin as the Dowidat. Besides being shorter, the BMW tire iron has rounded sides that will eat up your rim. They will make dents in an alloy rim and even slightly dent and “break” the chrome on a steel rim. Find better tire irons.
Do not use a screwdriver unless there is no other way. The square edges will eat up the rim, chew up the bead and punch a hole in the tube. Plan and have decent tire irons in your toolkit.
I am not showing the use of rim protectors, as this rim is already too far gone to consider. The irons will slightly mar the edge of the rim, but not nearly like the damage that is already there. I will show them for installing a tire.
My favorite tire irons don’t match, as I have had them “walk away” more than once and I reorder. I hope that they are still available.
This photo shows that the valve stem is crooked. This tells me that the tire and tube were probably mounted incorrectly. This is the “third” alarm signal.
The wheel weights are all mounted on one side. They should be split up with as close to equal weight on each side. It is possible that it needed this much weight to balance, but not likely. More likely that the installer didn’t know what he was doing. See my page on balancing a wheel. This is the “fourth” alarm signal. They are adding up fast.
The photo above shows some of the various valve stem caps. The purpose of the cap is to seal the air. If the valve core seals the air, that is great, but don’t expect it. The cap is your second line of defense.
From L. to R; Original cap from a Metzler tube. This one has the special valve core wrench and is very good. Next is some aftermarket cap that also has the wrench for the core. Next is some fancy chromed cap that may look great, but isn’t practical because it has no wrench. You now have to carry one in your toolkit. The one on the right is off of some “other brand” of an inner tube and is plastic. I have had them strip threads and fail to seal. Avoid junk like this. This tube had no cap. That is the “fifth” alarm signal.
It is time to remove the valve core to allow the air out. The air is out, and it is time to break the bead. Some are very easy, and some are impossible to do this way. I hope to use my feet to break the bead. I have had to tilt the bike over a bit and slide the tire under the center stand. Then use the weight of the bike, with mine, to put a lot of pressure in one small place to break the bead. Once it starts, walk it around, and the rest is fairly easy.
Another NO NO, the tire is oversize. This tire would be about a 4.50 X 18 and BMW recommends a 4.00 X 18. I highly recommend using the 4.00 tire. You should want to keep neutral steering. The correct size tire will more easily fit in place on the bike. This is just one more item that makes me highly suspicious of the previous owner and mechanic. Alarm signal six.
I use a paintbrush to goop up the sidewall that I want to come over the rim. I am currently out of the really good stuff, tire lube, so I use a mixture (50/50) of hand soap and water. Better stuff is available, and for the beginner, I strongly suggest buying real tire lube. The more of a beginner one is, the longer the whole process takes and the more valuable it is for the lube to stay wet longer. It can be purchased cheaply at any auto store. Just make sure that you keep the bead slippery wet. It is easy to have it dry out and give you trouble. In an emergency, I have had to pull a fuel line and use gas.
This photo was taken looking straight down. Now comes the balancing act. I have removed the nut that was on the valve stem and shoved it down and into the tire as much as possible. If it doesn’t want to go in, that means that the tire was mounted with the “valve stem patch” under the bead. Each manufacturer uses a valve stem mounted on a thick piece of rubber. That was cast into the tube, and you can feel that it is thicker. The tire would be crooked on the rim. That isn’t uncommon to find. In this case, the stem shoved into the tire cavity easily. I use my weight on each side of the valve stem. This is very important. See my page on the 5 dents. The bead is now in the center space of the rim. This allows the tire to shift over a bit to give maximum slack to get the tire off of the other side. It is essential always to start the bead coming off directly opposite the valve stem. This small advantage of less than 1/4″ is the difference between being able to do it and failing.
I had one customer who didn’t know this rule, and he had to use a cheater bar on the tire iron. He broke the bead on his brand new tire. He claimed the tire was defective……nada.
The tire irons are stuck under the bead and levered backward and over the rim. This first “bite” is the hardest one. There is a very small risk of pinching the tube while doing this. One will usually be replacing the tube anyway, so it matters none. I like to reuse a good tube. I judge by its feel and stretching ability. I can only do that because I have removed hundreds of them and know when they good or bad. Yes, I know that the manufacturers suggest that you always install a new tube, but is it really necessary? That is up to you, but I never found a downside to reusing a good tube. Maybe they want to sell new tubes.
I have removed the right iron and moved it over about 2″ and slid it back in. If you try to move it too far to the right, you won’t be able to get the tire iron in. There is a “sweet spot” to stick the iron in again. You may need to experiment to find it. One can sort of see where the space is for the iron to go in.
I have levered the right one over and moved the left one over a bit, same as above. I like to alternate to keep working directly opposite the stem.
The stem is still crooked, even after the bead is off on one side. I must check the tube for a wrinkle.
I lift the free side of the tire and sneak my hands in to grab the tube and pull it out.
The tube is partially out. Keep working it around the rim, and it will come free.
This is proof of poor workmanship. The tube is too small for a correct sized tire. Alarm signal seven. It is way too small for this oversized tire. The brand is Cheng Shin, a cheap tube with more plastic than rubber. This is alarm signal eight, but a minor one. Besides the economics, the advantage of this tube is availability, and it holds air well. The main disadvantage is that they can rip open easily and allow a sudden loss of air. We call that a blowout. The natural rubber inner tubes are more likely not to rip and only allow the air to escape slowly. The downsides are that they cost more, are harder to find and that they lose 1-2 lbs of air a week.
If you just once have this sudden loss of air while on a crowded freeway, you may well elect to find and pay for the natural rubber tubes. Both Metzler and Continental were natural rubber back in the day. I have no idea about this aspect in 2019.
In an emergency on the road, it is better to use a tube that is too small. I imagine that this tube was in there since the tire was installed. When I find this many errors, I know that one, or more idiots were involved somewhere.
I had to use a tube that was too large once, and it got me home but was folded up in the tire. The fold will weaken the tube and eventually fail. I was in the hills of Arkansas and more than 100 miles from any motorcycle shop. It was out of a Ford tractor front wheel. Do what you have to do, but fix it as soon as possible.
Now it is time to get the last bead off. Again, work on the opposite side of the valve stem, as this gives you the most slack. Stick a tire iron in and lever it over.
Whoa, not as easy as I thought it should be.
I had to slide a pipe over the tire iron to get the leverage needed to lever it over. Either the tire is much stronger than I expected, or I am that much weaker in my old age. Probably a bit of each. I have no idea what to suggest you use when on the road and you have to replace a tire.
Stick the other iron in as far away as possible and lever it over.
Keep working the irons farther apart. This one is about to come off.
BMW motorcycle wheel with a disc, or double disc brake
Laying the wheel down on the disc will probably cause it to warp. You will then need to get another disc. It is best to remove the disc during the work. One can lay the wheel on an old tire to hold the disc up and off of the surface. This will allow the disc to be on the bottom. If you have two discs, then you must remove the discs as they are in the way of the tire irons. It is an easy job to do. Be sure to tighten up the bolts and nuts properly.
More tire mounting errors
Yesterday I dismounted two tires from rims. One had been perfectly mounted, and all was OK. The other was a disaster waiting to happen. This is to show you more alarm signs. One should consider taking anything apart as an “autopsy” and use the information as a teaching experience. This will tell you how well the previous tire installer did. Best to learn from mistakes or you’ll keep repeating them.
I backed the valve stem nut off and, it allowed the stem to show the bad alignment. This tells me that something is wrong with the mounting of the tube. This is why one never tightens up the nut. Keep the nut loose as then you have an indicator of conditions.
This photo shows the wrinkle at the stem and another on the right. It is a failure waiting to happen.
Another fold in the center of the picture.
I have never seen this one before. The tube did not take on the shape of a donut. See the very curved part? It was folded up in the tire in that fashion. This is asking for trouble.
This is a front tire, and the size is shown as an example. While the size is correct, it is still a cheap off-brand tire. This is not a good way to save money.
This is an 18-inch tube. It is not for the 19″ tire that is on the bike. Next, see the size will fit up to a 4.50? The tube is way too large for the tire, even though the diameter is too small. This is about as stupid as it gets. This would be fine as a temporary measure to “get home” but not to ride on for years. The tube seems to be fair quality and still pliable. A cheap Chinese tube may not have survived this long. This owner was quite lucky.
Removing dings in a rim
This procedure only applies to the /2 alloy rims. They “push” around more easily than the /5 and later rims. I have had less success with steel rims. They tend to ding less, but get a big “wow” in the rim over a larger area. The chrome easily gets damaged too.
The camera distorts the rim a bit, but this photo is to show two “dings” in the rim. I marked each ding in blue. They are staggered a bit, indicating that they happened at different times. Someone tried to fix the upper one it by hammering on the rim. Aluminum does not respond to hammering, at least not as one would like. Questions about how to repair a ding are common, so here is how to do it.
The ding can be fixed by slowly pressing on the rim in the right place. This effect is called “cold flow” and is why a hammer won’t work. This is a small ding, and it needs pressure in a small area. The ding is over a 3″ part of the rim. I want to press on the center of the ding with a 1/2″ piece of wood. I like to use a piece of hardwood to protect the rim. I tape the wood in place just because I am working by myself. I protect the backside with a wide piece of wood. The wood will spread the pressure out on the good side.
One could use a hydraulic press, instead of a vise. I like to keep the pressure on for hours, and it could leak hydraulic fluid back. Besides, few owners have one available to them. A vise is far more common. This is a heavy-duty vise, and it is needed. A small vise probably won’t open far enough or have enough pressure. I like to crank it in a bit at a time just past where I want it to stay but not very much. I might crank the vise in a bit at a time, over a few hours.
This is the next morning, and it came out perfectly straight. I was lucky to fix it in one try. Now you can still see the ding on the right side, and it is larger than the one was on the left side. It is now in the vise but will take a few adjustments at hourly intervals.
Updated 2 Oct 2019