Leaking wheel

p3eps

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Dec 14, 2019
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Last week I fitted a new front tyre, and decided to go tubeless at the same time.
I have Specialized Roval Traverse carbon wheels - which came with tubeless valves.

I’d already done the rear 2 weeks prior without any issues, and have had several tubeless setups on my Stumpy’s over the years.

The DHF didn’t want to seat, and I didn’t have a charger pump, so I took the wheel with the tyre / glue in to my LBS. Happy to oblige, they inflated, and I went home.
By the time I was home (about 25mins) the tyre was nearly flat!
Thankfully it was still on the rim, so I was able to reinflate with my standard pump.
The leak was from the valve. I tightened it a bit... but that just changed from a huge leak to a smaller one.

I ordered my own Joe Blow Charger pump, and a set of Muc Off valves.
Yesterday, I swapped the valves over. Once again, no issue with the rear, but the front leaks from the valve. The Muc Off valves come with 3 different rubber fittings, so I tried all 3. Same issue. They say they should only be hand tight... so that’s what I did. I then tried a ‘little’ bit tighter. Same issue.
I then tried the Stan’s valves from my Stumpy. Same issue.

Seems to me that the wheel is the issue around the valve hole - and nothing will seal 100%. The standard Muc Off valve sealed enough for me to ride today, but I lost nearly 2psi over my 2 1/2 hour ride.

Any idea how I can fix this... or is this an issue I should go back to my LBS with? Bike is less than 4 weeks old, and the wheels are advertised as ‘tubeless ready’.
 

GrahamPaul

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Nov 6, 2019
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I had the same problem on my manual bike. Nothing would stop it leaking.

I eventually used a type of plumber's putty suitable for pressure jointing up to 15bar. It is a totally synthetic plastic substance. Worked like a charm.

I'd tell you it's name but... bloody lockdown - can't leave home to get to my garage. Sorry. :cry:

Edit: Just remembered, it's called Fermit.
 
Last edited:

steve_sordy

Wedding Crasher
Nov 5, 2018
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Its weird isn't it? The sealant seals big holes in the tyre and gaps at the rim, but not at the valve seat!!! I've had the same issue and solved it by putting 2-3 wraps of plumber's ptfe tape around the base of the valve before inserting it into the valve hole. Then I give the valve a gentle tap with a soft hammer before tightening the valve collar good and tight.

When I first started to read your post, I assumed it was yet another problem with rim tape. These can leak just enough for the tyre to inflate relatively easily, yet provide enough leakage that the tyre will not stay up, no matter how much sealant you use. After one too many rim tape problems, now I always replace the rim tape with Gorilla Tape - even on brand new wheels! I use the 25mm wide black stuff with the woven finish so that it looks like carbon fibre :)giggle:). Starting several inches before the valve I do two runs, finishing a few inches after the valve hole. Then I pierce a hole through and push a tapered item (like a bradawl) into the hole to widen it. Rotate the item back and forth to smooth out the rim tape in the valve hole. With the Gorilla tape and the ptfe, the valve always seals!
If the rim is wider than 25mm, I put one run to the left and one to the right. That ensures the spoke holes have at least have two runs covering them. If you only put one run over the spoke holes, the tyre will still inflate but the subsequent air pressure and riding the bike will depress the tape into the spoke holes. The next time you inflate a tyre, the bead may be over a line of those depressions and you will never get the tyre up, well not without dynamite! :eek:
 

p3eps

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Thanks guys...

I have PTFE tape in my work toolbox, so I guess that’s an easy place to start before ordering anything in.

Do you just put a blob of the Fermit round the hole and then jam the valve in?

I did manage to get it to seal... but as soon as I attached my pump to check the pressure, it started leaking again. Definitely something not right with the rim.
 

GrahamPaul

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Do you just put a blob of the Fermit round the hole and then jam the valve in?

I formed a "gasket" in Fermit around the base of the valve stem and then pressed it home. Worked a treat - and came out easily when I needed to remove the valve a year later.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
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Thanks guys...

I have PTFE tape in my work toolbox, so I guess that’s an easy place to start before ordering anything in.

Do you just put a blob of the Fermit round the hole and then jam the valve in?

I did manage to get it to seal... but as soon as I attached my pump to check the pressure, it started leaking again. Definitely something not right with the rim.

I'm suspecting that the problem is dodgy rim tape. Remember I said that it provides just enough of a seal to enable you to get the tyre up but not enough to hold pressure?
Before you throw the wheel across the garage, try a water test. Once a section of the wheel/tyre is immersed, don't be too quick to move on, allow a few seconds for any bubbles to appear. Ensure that whichever section is immersed that the whole of the tyre and rim in that section is fully under water. Rim tape problems can also be revealed through a very small vent hole drilled in the rim. I have seen sealant emerge from there before now!
 

p3eps

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It’s 100% coming from the valve hole.
I’ve got ‘Snoop’ which is a leak detector (basically Fairy Liquid / water in a fancy bottle!) Snoop® Liquid Leak Detector, 2 oz. (59 mL) Bottle | Swagelok
When I put some on the valve, it bubbles like crazy!

Once the pressure is below about 14psi, it doesn’t leak anymore.

Will take home a roll of thread tape (PTFE) tonight and try a little bit round the valve and see if that sorts it before buying something else in.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
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It’s 100% coming from the valve hole.
..................
Will take home a roll of thread tape (PTFE) tonight and try a little bit round the valve and see if that sorts it before buying something else in.

Don't just "try a little bit" around the valve. Put 2-3 turns, that should do it. If it doesn't, then put another 2 turns. Don't forget the gentle tap with a soft hammer. Or put a piece of wood on top and hit it with a hard hammer. Then tighten the valve collar. I use pliers, but don't overdo it!
 

RCDallas

Active member
May 28, 2019
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I had the same issue and I just put a little bit of Muckoff sealant on the base of the valve stem before inserting it into the rim...worked perfectly and hasn't lost any air since.
 

Zimmerframe

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I've seen this on one of mine before. Air was getting behind the rim tape, not coming out of spoke holes, but going around the rim between the tape then exiting at the valve hole. The Roval's are normally well taped, so you could be just unlucky.
 

ImSundee

Well-known member
Jan 20, 2020
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Oxford
I've seen this on one of mine before. Air was getting behind the rim tape, not coming out of spoke holes, but going around the rim between the tape then exiting at the valve hole. The Roval's are normally well taped, so you could be just unlucky.
This is what my thinking is on it.

I'd just throw some extra/fresh tape on it
 

p3eps

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With all that’s going on, tonight was my first chance to look at this again. The tyre was still relatively inflated - as it doesn’t seem to leak once it gets to about 14psi.

Anyway, tyre off (AGAIN!) and removed the valve. A quick clean, and I thought it try the simple / cheap option first. Put a couple of wraps of PTFE tape round the valve stem and then jammed it back in. Still hand tight, but really pushing the valve into the rim as I tightened.
160psi on my charger pump, and pop - back on the rim. Blew it up to about 45psi and bounced it about the floor to distribute the sealant. No obvious hissing... so I tried using my Snoop.
No obvious leak (was very obvious before), so I’m thinking / hoping that’s it sorted.

Will check the pressure tomorrow, but so far, so good.

Thanks for all the suggestions - much appreciated ??
 

Mikerb

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How well the valve seats depends a lot on the profile of the rim and regardless what shape rubber washer is used it will not seal until and unless that washer conforms to the shape of the part of the rim it is sitting in. So a couple of things can help. Firstly make sure the washer is relatively warm such that it is more malleable, second apply a very light amount of lube to the part that sits in the rim. Watch as you screw up the securing nut on the valve to see that the washer spreads a little but without bulging beyond the upper flat plate of the valve. I generally tighten the valve nut as hard as I can by hand without using tools.
 

outerlimits

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Just put a tube in it. Tubeless is going out of fashion anyway. ?‍♂️
If you can’t draw yourself away from tubeless then soak the rubber part of your tubeless valve in some bleach for an hour, then install as normal.
 

outerlimits

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I must get out more, I haven't heard that before. Is it the opinion of you and your riding buddies, or have you seen it reported anywhere that it is "a thing"?
I here it all too often. People complaining about tubeless, having problems setting it up, problems with it drying out ect ect and then they are like “I’m going back to tubes”
Facebook, forums, word on the street, yeah, it’s a thing that is growing.
I have gone back to tubes with Tannus Armour inserts. Much better than my tubeless set up in many ways.
So yeah, tubeless... it’s going out of fashion.
 

Jackware

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Oct 30, 2018
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Tubeless is a faff, I've set up 3 wheelsets tubeless and the time it takes to carefully tape a rim, get the tyre to pop into the rim and then ensure they don't dry out is too much for some people.
But I've never had a flat on those wheelsets, just the occasional weep of sealant where it's done its job.
However on my latest bike after changing the tyres I put the tubes back in and was done in about 10 minutes, though I've bought spares to carry with me. This was a calculated risk based on where I plan to use the bike.

Regarding the leaking valve stems, I've always made an extra 'washer' from an old inner tube that I've pushed the valve through before it goes through the rim and I've never had a leak from the valve/rim interface.
 

Mikerb

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Much less faff if the wheel is tubeless ready and the tyre is tubeless. On my Levo it took no more time than fitting a tube. It just meant buying some Stans.
 

Mikerb

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May 16, 2019
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Last ride out my ride partner...same bike same tyres and virtually the same lines as me just managed to get back before his rear tyre went flat. When he checked back home he had 4 punctures. Mine was fine.
 

Waynetta

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Feb 11, 2020
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Took me a long time to go tubeles, much to my riding buddies piss taking every time I had to stop the group. We have a lot of gauze bushes and brambles as well as black thorn trees. I probably got a puncture every second ride. Got a bit embarrassing so went tubeless. bought some wheels off a mate, a bottle of stans and took all of 10mins to do. Not had a puncture since. Had to top up both wheels about 6 months later as the pressure started to drop over a couple days. Wouldn’t go back to tubes now.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
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[QUOTE="outerlimits, post: 150607, member: 119".................., tubeless... it’s going out of fashion.[/QUOTE]

Not with me its not! Judging by the number of punctures I've had in my tubeless tyres (without any flats), I have saved hours by the side of the trail repairing inner tubes and all that entails..
 

Zimmerframe

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Statistically, @steve_sordy is unluckier than the average rider ...

Steve.jpg
 

Gary

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With the Gorilla tape and the ptfe, the valve always seals!
If the rim is wider than 25mm, I put one run to the left and one to the right. That ensures the spoke holes have at least have two runs covering them. If you only put one run over the spoke holes, the tyre will still inflate but the subsequent air pressure and riding the bike will depress the tape into the spoke holes.
Dafuq?

Gorilla tape isn't even air tight. it relys on sealant to become airtight.
gorilla tape clear is airtight.

One wrap of an actual air tight tape (like TESA 4289) will seal any rim it'll stick to.
Good luck changing it if you've previously gorilla taped the shit out of it though, removing gorilla/gaffer tape resedue completely from some rimwells can take hours.

also, it's only the spoke holes that need taping over so you don't actually need anymore than 25mm width to cover them no matter how wide your rims are. Folk think it needs to stretch to the edge of the rim and meet the tyre bead. It doesn't. your tyre will seal to the rim if you simply smear sealant around the bead when inflating/creating the seal.
The only reason any in tact rim might need taping all the way to the edge of the rim is if it has a pinned rim joint but proper tubeless ready rims shouldn't have pinned joints and thus won't be an issue.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
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Statistically, @steve_sordy is unluckier than the average rider ...

View attachment 27714
Yep that's pretty much what happened!

As witnessed by the damp patches on a dry wheel left overnight, I had over two dozen punctures in each tyre. All I had to do was to keep topping up the sealant. No flats though!

For the avoidance of doubt, those punctures did not happen in one epic ride, but over a couple of years. Mostly ridden in the woods.
 

RCDallas

Active member
May 28, 2019
152
151
Italy
When changing the rear tire of my Salvador XC bike, purchased with tubless back in 2012, I counted 26 visible or detectable to the touch punctures...and I didn't have a single failure on the trails due to a puncture. The tire failed from de-lamination of the tread to the casing causing a large bubble which made it unrideable. Interestingly, I never added any extra sealant during the life of the tire and it actually sealed the bubble when I popped it in order to get back home. Not sure what sealant was used by the LBS back then but it created a thin, pliable, rubbery coating on the inside of the tire that did not ball up or dry out...unlike any of the other sealants I have used since. I'd say that MucOff which I'm currently using is the closest to it but still not as rubbery.
 

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