Can't get 20 x 4 tire off rim

murbot

Member
Region
USA
City
MOUNT AIRY, MD USA
Changing out the 3.3" CST tires with 4.0" Mongoose tires. Struggled more than any tire I've installed, but got it on the rim with the tube and Tannus secure inside and on the rim. I inflated the tube slightly beforehand and it was fine. After installing the tube and getting the tire fully mounted, I can't get air into the tube. I've got a good hand pump and an air compressor, but both have trouble blowing into the valve. They either get blocked or blow outside the valve. Again, the valve worked fine before install and the pin doesn't seem stuck. The pumps test fine on other tires.

Now it seems almost impossible to get the Mongoose off the rim to inspect the tube. I'll take it to a shop tomorrow, but any suggestions in the meantime? Anybody run into a similar issue with the valve? Any tricks to getting a 4" tire off the rim beyond the typical YouTube stuff? My levers are bending and snapping.

Thanks for any ideas or suggestions.
 

ian fisher

Member
Changing out the 3.3" CST tires with 4.0" Mongoose tires. Struggled more than any tire I've installed, but got it on the rim with the tube and Tannus secure inside and on the rim. I inflated the tube slightly beforehand and it was fine. After installing the tube and getting the tire fully mounted, I can't get air into the tube. I've got a good hand pump and an air compressor, but both have trouble blowing into the valve. They either get blocked or blow outside the valve. Again, the valve worked fine before install and the pin doesn't seem stuck. The pumps test fine on other tires.

Now it seems almost impossible to get the Mongoose off the rim to inspect the tube. I'll take it to a shop tomorrow, but any suggestions in the meantime? Anybody run into a similar issue with the valve? Any tricks to getting a 4" tire off the rim beyond the typical YouTube stuff? My levers are bending and snapping.

Thanks for any ideas or suggestions.
you could try pouring boiling water on the tyre bead to soften it? also maybe try lubricate the valve with something, wd40.., could be just some grit stuck in the valve. a drop of warm water in the pump fitting, it's sometimes difficult to get the pump fitting seated down on a partially inflated tube, if it's not down and locked on correctly it will do as you you have described and not allow the valve to open.
 

murbot

Member
Region
USA
City
MOUNT AIRY, MD USA
No luck so far. The tire has a metal ring in the bead so hot water doesn't help. Tried a small local shop this morning, but they weren't able to get the new tire off and confirmed the tube has a hole. I'll take it to a larger shop when they open in an hour. If they can't do it, I'll give Dawn dish soap a try and then cut the Mongoose off if that fails.
Can't wait to ride my new bike. LOL
 

PedalUma

Well-Known Member
Region
USA
City
Petaluma, CA
Do not use petroleum oil in your valve. Silicone oil or grease is what you need because silicone is compatible with rubber. A drop of fishing reel lube will also work.
Squeeze the tire beads in all the way around. There is more room at the center of the rim. Work the beads to the rim's center from the opposite side of where you want to insert the lever. This will give you slack and it will pop off.
 

murbot

Member
Region
USA
City
MOUNT AIRY, MD USA
Thanks for the tips. The closest, smallest shop ended up being the one that could fix it. Tried a couple others, but this guy was the type you always want to deal with. He admitted it was still a struggle, but both Mongoose tires are mounted...with Tannus foam included. He'll be happy to see me in the spring when I show up with Kendas. LOL
I bent 3 Park (plastic) levers trying to dismount the Mongoose myself (to remove the punctured tube). He doesn't use metal levers either. I think he used Pedros levers.

Now I have knobs to handle the snow with. :)
 

Mike TowpathTraveler

Well-Known Member
A few years back, I got a flat on the rear tire of my Haibike Full FatSix.....80mm wide rim, Schwalbe Jumbo Jim 4.0 wide tires. As I've already had many flattened tires on this bike and my Specialized Fatboy, I thought it was no big deal. This time, it was. Trying to squeeze the tire bead off the rim, getting the plastic tire levers, it took a good hour before it let go.

But I did find a sure-fire way of breaking a tire bead from the rim when getting a flat tire out in the field, where bike shops and hot water are nowhere to be found"

Place the tire/rim assembly on the ground (grass is preferable, asphalt or dirt/rocks is not as you don't want to scratch the rim)......... Brake rotor side, UP........ placing your left foot at about the 8 o'clock position on the tire/rim (to steady the tire in place); you then place your right foot at the 5 o'clock position on the tire, your insole running parallel with the edge of the rim. Using the heel of your right foot, stamp sharply downward until the tire bead releases. Once it releases, you can then use your tire levers or hands to work it off the rim. You can then carefully repeat on the brake rotor side, being careful to not put weight on the rotor and bending it. Or try to work it off by hand and brake levers.

It works everytime. I can only speak about the fitment of my Schwalbes with these rims, but the tires always seated on the rim with a sharp "Bang!!", meaning it was LOCKED in place and no manhandling with the hand would ever break that bead.

Hope this helps. Trust me, it took longer for me to type it all out, than to actually do it!