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I've run tubeless for some while without issue on various bikes. I've once had a leaky valve before but nothing that a thorough clean of the valve and rim wouldn't solve.
However...recently changed tyres on the rear of my Solaris, and now air is fizzing out out the interface between valve and rim. Albeit...periodically. Sometimes it stops for a while. And then happens again. Tried the above...thorough clean and even smeared some fresh stans on the rubber of the valve to create a little more of a seal.. No joy. Bought a new valve. Same thing happening.
The tape looks to still be flush with the rim with no nicks from tyre levers. The wheel's not taken a knock.
Help! Any ideas? Reckon an extra layer of tape for the couple of inches around the valve may help?
Probably tape related - however I had something similar driving me mad which I just couldn’t sort out in spite of retaping more than once - in the end I popped a small o ring between the valve and rim and presto it stopped!
I just tried the o-ring. If anything it was worse that the metal on metal! My rims are assymetric too so it’s not a flat exterior surface. That said- it’s not mattered before!
Have a close look for small cracks around the hole
Maybe you damaged the rim tape when you changed tyres and the air is travelling round the inside of the rim then exiting at the valve
Try some plumbers tape round the base of the valve. That tends to work for me.
failing that, re-tape it.
What jonnyboi said - almost always the cause.
Maybe you damaged the rim tape when you changed tyres and the air is travelling round the inside of the rim then exiting at the valve
Am wondering that. Maybe an errant dig with a tyre lever. But wouldn’t that just exit through the spoke holes? They’re air tight.
A leak anywhere around the rim will come out through the valve hole. Spokes seal to the lower rim bed much better than the valve which is only sealed to the upper rim bed
Ok cheers.
<div>pdw
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A leak anywhere around the rim will come out through the valve hole. Spokes seal to the lower rim bed much better than the valve which is only sealed to the upper rim bed
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Good point that, never thought of that before will try and remember for future reference.👍
Personally, I'd just re-tape. It would take longer to post here than to just strip the old tape, clean the rim and put some new stuff on and have done.
Someone suggested using a soldering iron to create the valve hole - what a damn good idea that was. You can make the whole exactly the size you need (i.e. fractionally smaller than the valve and because it's a circular hole, with a nice build up of plastic around the edge, it should be much more rugged to having valves in and out. Certainly, the pair I did at the weekend, which were a faff and needed tubes in and out a couple of times before setting down, had no issues at all. Highly recommended!
New tape ordered. I’ll clean the rim before retaping. I’m assuming isopropyl alcohol wipes or something similar is best for that job?
pdw's spot on, spoke holes are actually pretty airtight so any leaks anywhere go out the valve. It could still be the valve, but since it happened when you changed tyres, it's almost certainly the tape. It can get pushed over when you change tyres, especially if the tape's not quite as wide as the rim
Incidentally- if it's a nice big wide rim, you can avoid taping the mating surfaces entirely and just tape the "bed", ie use narrow tape and just to the middle. Most folks don't do this, but it makes for a pretty indestructible tape job because when you change tyres there's no contact
O-rings outside the rim don't do anything fwiw, no point to them.
Just had this today with my wife's wheels - freshly and very carefully taped DT rims. Circular / conical Stans type valves just wouldn't seal 100%. DT supply valves with a larger rectangular rubber block - dug out a couple of these and both sealed perfectly.
A quick update.
The old tape had lifted slightly - not by the valve and, as mentioned above, was escaping through the valve. A couple of sore thumbs installing new tape and all is good in the world again.
Had this a fair bit, I always think "it can't be the tape, it's new" but then I retape and it's fine. Luckily have a decent sized roll of tesa tape on standby. If you can't get the tape to stick, or you decide to retape your wheels in the shed on a cold winters night, leave the tyre with a tube, inflated, over night and it will press it all together nicely.
Tape will often lift enough at the overlap point to let air through - and this can be intermittent as the sealant tries to work.
Another good reason for using tape that is wider than the rim is that the tyre, once fitted, will hold the edges on.
Yep, had this, though didn't help getting a nail on the opposite side of the wheel go through the tyre and punctured the rim bed (carbon rim). Air went into the rim cavity and came out the valve hole.
Fixable by taping up the extra hole, but took several attempts as for some reason it still kept leaking air under the tape into the hole from somewhere. The rim is a pain to get tyres on and think the bead kept catching on some tape, and maybe the tyre levers were damaging the tape also.