I keep getting blowouts due to the tirescoming up over the rim and the tube sticking out with them.
The psi is only about 80 to 100. The tires say 120 psi max. 27 x 1"
The rims are old Campagnola made in France.
What gives?
Tires keep coming up over rims
- Thread starter 101RoadRider
- Start date
I keep getting blowouts due to the tirescoming up over the rim and the tube sticking out with them.
The psi is only about 80 to 100. The tires say 120 psi max. 27 x 1"
The rims are old Campagnola made in France.
What gives?
I don't know the rims specifically, but if they are old non-hooked rims, then you are only good up to about 60-70 PSI, no matter what the tires say.
The way to tell, is if there is no lip inside the rim, and it just goes straight down, you should stick to lower preassure.
Also, I am not sure if it is even possible, but maybe you are using 27" tires on a 700c rim??? A 700c rim is a couple of millimeters smaller than a 27" but I don't if the difference is small enough to look like they fit right.
The way to tell, is if there is no lip inside the rim, and it just goes straight down, you should stick to lower preassure.
Also, I am not sure if it is even possible, but maybe you are using 27" tires on a 700c rim??? A 700c rim is a couple of millimeters smaller than a 27" but I don't if the difference is small enough to look like they fit right.
assuming you have the right size tires and the proper tires for your rim, here's another thing to check:
one (common) cause of tires blowing off rims with the tube sticking out - using tire levers to install the tire.
you should avoid using tire levers to install the tire. if you do, it's very easy to end up with some of the tube underneath the tire bead.
after you pump up your tire, the tube bit under the tube is a timebomb just waiting to go off. once air gets under the bead, you have a few seconds before your tube goes ka-blam.
check to see if this is happening.
cdr
one (common) cause of tires blowing off rims with the tube sticking out - using tire levers to install the tire.
you should avoid using tire levers to install the tire. if you do, it's very easy to end up with some of the tube underneath the tire bead.
after you pump up your tire, the tube bit under the tube is a timebomb just waiting to go off. once air gets under the bead, you have a few seconds before your tube goes ka-blam.
check to see if this is happening.
cdr
Carpediem is right--sloppy installation which leaves the tube between the tire and the rim is death. The best way to ensure that your tube is properly seated is to pump it up slightly inside the tire and to squeeze the tire/tube combination between thumb and forefinger all the way around the tire while checking visually as you do so to see that no part of the tube protrudes from under the tire i.e. that the tube is properly seated inside the tire. Also, push the valve up through the valve hole to ensure seating of the tube in the stem area. Given the inordinate amount of flats I have had over the years (until I began using SpinSkins), I developed a certain level of expertise in this sort of thing...it helps if you put talcum powder on the inside of the tire so that the tube can seat itself more easily.
uhm... How do you install a tire without tire levers, I find this
to be a daunting task to say the least.
to be a daunting task to say the least.
101RoadRider said:uhm... How do you install a tire without tire levers, I find this
to be a daunting task to say the least.
- Place one entire bead on the rim with a very lightly inflated tube inside the tire starting at the valve stem and ending opposite the valve stem.
- Start installing the second bead directly opposite the valve stem and work in both directions rolling the tire up and over first using your thumbs and then using mostly your palms with the wheel held out in front of you and the bead being installed facing you.
- As you near the valve stem working from both sides it'll start to get tough, work in small increments gripping the tire but mostly rolling with your palms.
- At the last bit (the valve stem) press the valve up and into the tire to make sure the tube doesn't get pinched and then roll the last bit up and over. This is the advantage of working this way, you can use the valve stem itself to help eliminate tube pinches in the last section where pinches are most likely.
- Pump just a bit more air into the tube to and go all the way around as a previous poster suggested pinching the tube, wiggling it side to side and visually inspecting to make sure the tube isn't pinched anywhere. Also make sure the beads are seated correctly in the rims, sometimes you'll get a tiny pop from place to place as the bead seats in during this pinch checking.
- Pump the tire the rest of the way up, give it a good once over look to make sure the bead is still evenly seated and then go ride.
Good luck.
Velonews video, January 3rd tech tips with leonard Zinn.101RoadRider said:uhm... How do you install a tire without tire levers, I find this
to be a daunting task to say the least.
http://www.velonews.com/
One trick is baby powder on the tube and the tire bead. but you should be able to install a tire with levers. I use one plastic lever, "Quick stick", for 10 years, never had a pinch flat.
Allowing that you have the correctly sized tires for your rims, what comes to mind is that you-or-someone-else may have installed rim tape that is too wide for the rim ... which might result in the bead of the tire not being adequately hooked by the rim.101RoadRider said:
coming up over the rim and the tube sticking out with them.
The psi is only about 80 to 100. The tires say 120 psi max. 27 x 1"
The rims are old Campagnola made in France.
What gives?
If you are using tubes without sealant, then lightly talc the inside of the tires ...
If your tubes have sealant, then lightly "dust" the inside of your tires with some corn starch.
INITIALLY, after you seat one side of the tire, I recommend (but have seen others say differently) you seat the valve of the inner tube + the tube with a minimal amount of air to give it some shape ... insert the tube in tire ... seat the other side beginng at the valve AND working (from both sides of the valve) toward the opposite side. Inflate to full pressure of between 80-95PSI.
Don't worry about what the maximum PSI rating on the sidewall is ... I have friends who still insist on putting over 135PSI in their tires because the sidewall says 140PSI-or-something.
Good luck!
BTW. Depending on the age of your rims, if the width is wider than 15mm (bead to bead ... e.g., the MAVIC MA40 & predecessor rims such as the MA-2 presumably have a 15mm bead-to-bead dimension similar to their comparably named 700c rims), then the tire may be the wrong size for the rim ...101RoadRider said:
So if your rims are 630-17 (i.e., 17mm bead-to-bead) or wider, you may need to go with a 27 x 1.125" or 27 x 1.25" tire.
re: installing a tire without levers - I find the best way to get a LOT of leverage on the tire bead is to use my fingers and pull the bead over the rim. This means you're facing the side of the rim that is already mounted and you're pulling the bead towards you on the far side of the wheel/rim. 8 fingers is better than 2 thumbs. Also work one side of the bead at a time. Don't try and get both ends of the bead over the rim at the same time - just work on one side till the bead pops onto the rim. Friction should hold the other side in place.
Ultimately you can use levers but you have to be very careful to verify that the tube is inside the tire, not under the bead.
I changed tires/tubes virtually daily for about 15-16 years and the half-joke we told each other is we had 9 minutes to finish a tire/tube replacement to break even. Tight tires (which means tight rims, since new tire dimensions are strictly controlled) would really press us with this time limit.
cdr
Ultimately you can use levers but you have to be very careful to verify that the tube is inside the tire, not under the bead.
I changed tires/tubes virtually daily for about 15-16 years and the half-joke we told each other is we had 9 minutes to finish a tire/tube replacement to break even. Tight tires (which means tight rims, since new tire dimensions are strictly controlled) would really press us with this time limit.
cdr
Okay, I admit it. I use a tire iron to save my thumbs and fingers. I simply flip it so that the end going under the tire is slanted downward toward the rim to try and avoid pinching the tube which is the problem to which everyone is alluding. I slide it in carefully to avoid pinching the tube. I have done it many times without using a tire iron but really don't like how my digits feel while doing so. Mea Culpa; take me out and shoot me for violating the eleventh commandment: Thou shalt not mount a tire using a tire iron. Whip me, flay me, by the living God that made me, you're a better man than I am , Gunga Din.
Its not hard actually... i do this all the time on folding tires of course. Hard to describe it in words... better to show it how. Let me see if I can take sequential shots or maybe a video how i do it.101RoadRider said:uhm... How do you install a tire without tire levers, I find this
to be a daunting task to say the least.
*an exception to this is when installing tires on campy rims, specially with french tires*
heh I just mounted two new Michelin tires on my Eurus wheels. I was thinking about this post when I did it. I'll have to mount another new tire and video tape it. It takes a couple minutes for each tire. The biggest pain is getting the folded up tire to sit in a relatively round shape as you install it.
cdr
cdr
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