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Discussion Starter · #1 ·
Just got a set of carbon wheels setting up tubeless & having a problem getting the valve stems to seat without leaking, I taped the rims poked a hole for the valve tightened it down & added air & it is leaking, I tried three different stems. Should I remove the tape that flapped into the hole? I only did one wrap of tape should I do 2? Any tips or suggestions would be appreciated.
 

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What type of hole did you make? slice, round, X? I've never missed with a small X-cross cut tight and having it enlarge itself with the valve being pushed through. But could see Whispers method working because of the lack of a potential "seam" developing.
 

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Discussion Starter · #6 ·
I have always used the X cut on my older rims most of the time it worked flawlessly but once in awhile I had to use pliers to get it sealed, I am afraid to have to resort to that on carbon (which I have done the X cut)
 

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Hole is too small. Ad a touch of rubber cement around the valve or hit it with a tapered reamer

Sent from my Nexus 7 using Tapatalk
 

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I've had to use pliers to get get the nut tight enough to not leak.

That was on a Roval Traverse wheelset, no idea the brand of the valves (they came free with the wheels). My Bontrager Race Lites with Bontrager valves worked just finger tight.

Both wheels had strips installed, no tape, and didn't need any other methods to eliminate leaking through the valve stem area.
 

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mtbpete
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You can use a round file to shave away any tape around the valve hole, but this is completely unnecessary. It looks like you have a leak somewhere else in the tape. The rubber stopper of the valve usually seals very well so it is rare that this is the problem.

What is your indication that it is leaking at the valve?

NOTE: The valve does not seal the outside of the rim only the inside.

If you see sealant or air coming out at the valve area you could have a leak anywhere on the inside of the rim. If the tape is not wide enough for the tire to sit on or if there's a hole in the tape or a gap anywhere then sealant will get under the tape, into a spoke hole and travel through the channel of the rim and escape out the largest hole on the outside of the rim, which is the valve area. The valve hole on the outside is not sealed, nor should it be. You do not want to fill the inside of your rim with sealant.
 

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I dip the rubber end of the valve stem in sealant and then tighten the nut pretty tight. It works.
 

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Sorry to resurrect an old thread, but I'm having this trouble too.

New Carbon wheelset, with DHR2 and DHF tires. DHR2 set up without a hitch, aired up and held air for hours, refilled a couple of times and it was holding air overnight with no sealant.

DHF doesn't seem to hold air - pumped it up as high as 60psi beads seem set, but it deflates in minutes. Sounds like it's coming from the valve hole.

Before I make a mess with the sealant inside the new rim & tires, would like it to be holding air.

Should I retape the rim? The builder taped the wheels, not sure if he cleaned the rim very well and I had to wait a few days for the DHF to arrive. It could be that the tape isn't adhering to the rim.

Any tips?
 

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What type of valves are you using? I find the valves with o-rings (American Classic or similar) work better than the Stan's plug style valves.

I've got an extra set of o-ring valves you could have. PM me :thumbsup:
 

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I'm using some WTB valves, no o-ring on them, but I bet I could pick one up at the local hardware store.

These are LB 38 mm rims - I'm thinking of trying to reseat the valve first.

If that doesn't work, probably just tear it down - remove tire, valve & tape, clean the rim well, retape & reseat the valve and try again.
 
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