Bicycle Mechanics - Tube won't tuck under tire -- ???

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marrzipan
01-19-10, 10:28 PM
so i replaced my tubes today (700c) and it was business as usual. but, this is my first time using a tube with a presta valve. not sure if the valve is a big deal though.
but around the valve, the tube doesn't seem to tuck in underneath the tire. i re-did the tubing and it's still the same. my fingers are a bit sore from trying to play with the tube in that area, so i can't be bothered with re-doing it again tonight.
any tips, advice, criticisms? greatly appreciated!
thank you.
DieselDan
01-19-10, 10:39 PM
You have to work the valve area inside the beads gently. It may take some practice.
BCRider
01-19-10, 10:51 PM
Just push the valve area in and hold it while you seat the rest of the tire.
It may well be the brand of tube you're using. I've never had an issue with the tube around the valve area.
I always tuck in the tube at the valve first. Try that.
Wanderer
01-20-10, 07:11 AM
Does the Presta fit your rims?
barturtle
01-20-10, 07:39 AM
With narrower rims, the reinforced area around the valve can get in the way of seating the tire bead. If you're using threaded valved, loosen the nut on the valve so you can push the valve part way back into the rim and allow the bead room to move under the reinforced area of the tube. After the whole bead is seated you can then retighten to valve nut.
Two suggestions.
1- Put enough air into the tube to give it shape before installing it. this makes it far easier to push into the tire and the shape keeps it well in the tire reducing the chance of pinching it between the tite and rim. You might have to bleed some of the air out as you finish the installation.
2- Mount the tire starting opposite and ending at the valve. Then gently push the valve in so as to bring the reinforced section at the base well up into the tire, ease the beads into position and pull the valve back down settling the tube above the tire.
One last thought, anticipating a future problem. If you're using a Presta valve tube with a rim drilled for Schrader valves, use a grommet or valve hole adapter to protect the base of the valve from the corners of the oversize hole. Otherwise there's a decent chance of the tube getting cut there, or the valve extruding out at high pressure. Years ago when there were no ready made adapters, I used the sticky fiber reinforcements they used to sell for looseleaf notebook pages. Just slide two of them glued to each other down the valve before installing the tube.
Homebrew01
01-20-10, 10:26 AM
Two suggestions.
1- Put enough air into the tube to give it shape before installing it. this makes it far easier to push into the tire and the shape keeps it well in the tire reducing the chance of pinching it between the tite and rim. You might have to bleed some of the air out as you finish the installation.
2- Mount the tire starting opposite and ending at the valve. Then gently push the valve in so as to bring the reinforced section at the base well up into the tire, ease the beads into position and pull the valve back down settling the tube above the tire.
I do it the opposite way. Starting at the valve means the tire is loosest and easier to wiggle the valve into it's spot.
With wire bead, or a foldable that holds it's shape, I put a puff of air into the tube, mount it inside the tire, then mount them together onto the rim. Always seemd the eaisest way to me. With a new, floppy foldable, it doesn't work.
What I found works for me:
I blow into the tube with my mouth to give the tube some shape. As much air as I can blow in, is about right.
I push the valve through the rim first, then install the rest of the tube in place and seat the tire bead.
At this point if the bead has not seated near the valve I push the valve back into the tire which allows the bead to seat.
Al
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