BikeCo Tips & Tricks: Dismount Tire, Repair Tape & Remount Tire
Here’s a How-To showing how to remove an MTB tire, repair tubeless tape and remount the tire.
Video & blog below! (PS, excuse some of the wind / street / cat in the audio – we’ve wanted to make sure client’s have access to these especially during our busy season so I’ve been shooting at home – one of my cat’s was quite tired of watching a days worth of video shoots without getting attention in this one!)
This How-To covers a handful of things that can help keep you on the trail.
Or, review just the parts that you need to refresh on!
I had been shooting How-To videos the day before when after adding tubeless sealant to this wheel it quit holding air. The old “don’t go looking for problems, you’ll find them” type thing…
This video goes through the steps in trouble shooting a tubeless MTB wheel, dismounting the tire, correcting tubeless tape and reinstalling the tire.
Not Holding Air
To begin let’s look at some reasons the tire may not hold air. I always suggest looking at the simple problems first.
Is the valve core and valve stem tight?
Does the tire have a cut or puncture? Is there tubeless sealant on the outside of the tire?
Is there tubeless sealant on the rim near the nipples? This would suggest a tape failure, but most of the time it would be a hell of a failure to see this.
Dismount MTB Tire
With sidewalls getting more aggressive it can be a bit of work to get a MTB tire off. Luckily there are tricks that will help you.
To remove the tire you need to unbead, or break the bead, which is where the tire and rim interface. You’re not literally trying to “break” the tire, simply breaking the air tight seal. Then move the bead into the rim trough (the smaller diameter “V” in the rim).
If you can’t easily break the bead with your hand a tire lever is a great tool. You can set the tire flat on the ground and push the tire iron vertically into the tire to move the bead. Repeat this in a circle around the tire. A trash can is a good surface to work on as well.
Note – this step is particularly important if you’re running CushCore or equivalent rim protection.
When the tire’s bead is entirely in the rim trough you can pull one section over the rim edge. If you have asymmetrical rims pull the tire over the short side (it will make your life easier). Without the bead in the trough the tire’s bead will have to stretch over the rim edge, rather than using the change of depth in the trough. Don’t get lazy, get the entire bead into the trough.
If you use a tire lever make sure to use it as a “spoon” to scoop the bead out, rather than to “pry” the other way. This will help protect your tubeless tape edge.
Once the tire is about 1/4 or 1/3 off it’s pretty easy work.
Inspect & Repair Tubeless Tape
My wheel had two areas where the tape wasn’t making a good seal. Looking at it in depth I noticed that the tape had started to peel some time ago, and I must have just moved it that last little bit the day prior shooting video. I could tell this because the tape’s adhesive side had variable amounts of dirt / debris on it. But, once the spoke hole was exposed it simply wasn’t going to hold air.
The best practice would be to replace the entirety of the tape. In this video however I wanted to try to just correct a section of tape to see how it would work.
I cut out the damaged area of tape. Be careful not to create stress risers in the rim if you trim a section out. (ie don’t cut deep into the material, just try to split the tape)
Whether you’re replacing a small area or the entire tape you must get the rim very clean. Tubeless sealant residue means nothing will stick. I used Muc-Off followed by window cleaner and then let it all sit in the sun for some time. Feel the rim to ensure the “greasy” residue is gone.
When you tape a rim you have to really pull the tape tight as you apply it. The stretch gives the tape some bite. If you simply try to put tape on it won’t stick to anything and is super frustrating.
This also creates an interesting situation if you’re trying to tape only a small section rather than the entire wheel. Namely, you can’t really get the “stretch and bite” on a couple inches of tubeless tape. You really need to start before the damage, stretch and apply the tape, then pass the damaged area by a bit.
In the video you see I put a single addition of tape rather than multiples (I had two failed areas). It would have been harder to do smaller sections and get them to stick.
After you get the tape down push out the excess air out of the sides. Push the tape down firmly across the radius. You can use your thumb or put a rag over your thumb to minimize the friction build up.
Your tape should be well adhered. If it seems flaky do it again. There’s nothing worse than having to take tires on and off over and over (again, this is why it’s probably a good idea to tape the entire wheel in this situation).
Install an MTB Tire
A new tire is usually tighter than remounting a previously mounted tire.
My favorite tip on new tire installation – set the tire in the sun and let it heat up a bit. It will be more malleable and easier to mount.
Like removing the tire, if you have an asymmetrical rim install the tire over the short side. Don’t make your life harder than it needs to be.
Make sure the bead sits all the way in the trough to ease installation.
If you use a tire lever use it as a spoon to scoop the tire in without digging into the tubeless tape.
Truly, it’s going to make it so much easier, get the bead into the trough. Occasionally I get lazy and think I don’t have to – but it’s so much easier on you and the tire if you do. In fact, with some really tight interfaces you can damage the bead if you put too much pressure on it. Give yourself the advantage of the smaller diameter with the bead in the trough.
Inflating a Tubeless MTB Tire
The key to setting the bead and inflating a tubeless MTB tire is volume of air.
I find removing the valve core is the easiest way to quickly pump in a large volume of air whether you’re working with a hand pump or a compressor.
Installing a tubeless tire with a hand pump
If you watched the video you saw success, and failure, on the hand pump method… I success about 8 times out of 10. Maybe 9 times out of ten. But, if I was going to fail I thought it was fair to show it…
In the successful overlay video you see my preferred technique. Since I remove the valve core you probably have to hold the pump onto the stem. I apply some pressure to the top of the tire with my thumb. This gives me a bit more “bite” on the pump as well as creates a bit of pressure on the tire bead near the valve stem.
If you slowly rotate and “bounce” the tire it helps mounting with a hand pump. It gives the tire just a bit of a nudge to move the bead and slightly compresses the volume (allowing the internal psi to slightly rise).
Once you set the bead, usually accompanied by a couple loud clicks, you install the valve core and set your PSI.
Whether you use a hand pump or compressor make sure that the bead is evenly seated. There typically is a line around the edge of the tire that should have even spacing to the rim.
Sometimes it doesn’t want to mount with a hand pump easily. A compressor will quickly mount the tire.
Mounting a tubeless MTB tire with a compressor
As I’ve gotten older I like things easier. I’m not really into the day to day chores “for the challenge”.
If you have a compressor at home your life is easier. If you’re on the road a compressor or even just a tank will give you air at the trailhead.
With the valve core removed I use an air gun to set the bead. Its high volume and fast. I don’t have to find presta adapters, etc.
Now, be sure not to over inflate the tire doing this! Never try to set a bead above 30 or so PSI in the tire (modern rims and tires aren’t designed for it).
If you over inflate a tire while mounting it you have a serious risk of damaging the tire, rim, wheel and yourself… Get the bead to set and that’s it. Don’t put road pressure in it or you’re going to have an explosive situation in your hands. And it’s going to hurt.
We hope this how-to makes your home tire install and wheel service a little bit easier.