So, I have an issue with a tubeless wheel. I bought a set of Nukeproof Neutron V2 wheels for my hardtail last summer. Fitted a nice new set of Maxxis tyres. All good, or so it seemed. After 3 rides or so I got a small puncture in the rear. Sealant seemed to do its job nicely. Since then, the rear goes down after a ride. Fine during it. The very small hole has sealed, or so it seems anyway. I have since discovered the air is leaking from the valve where it touches the rim on the outside. Now, the internet tells me this is normal, so where is the air leaking from? What do I need to go through to find the source of the issue? New rim tape, new valve, new tyre, new sealant?

I’ve had tubeless on my MTBs for a couple of years now, and I’m not convinced it’s any better than having tubes. When riding, having no tubes has an advantage of course. When you get a puncture, it seems to be a world of ballache.

And yes, I know I could just run tubes, but why when I have a tubeless setup.

Spray bottle with some slightly soapy water in. Pump tyre up then spray the beads, spoke holes and valve. It should show any leaks. No, it shouldn’t beeaking from the valve, suggests it needs tightening or replacing.

Leading from the valve is usually a leak in the tape. It goes into the rim cavity, then out through the path of least resistance, which is usually the valve hole.

Given the puncture seems to have been the source of the problems, you should fix it with a mushroom patch from the inside first things first.

If it is still going down then it probably needs a re-tape – you can get a bad valve fit but much more common for it to be just air getting past the tape and just escaping by path of least resistance (through rim-joint is another place).

Thanks for the suggestions.

And there is the issue, could be this, could be that. It’s going to cost me at least some new rim tape which I hear is not easy to fit.

What is a mushroom patch?

Valve leaks generally always mean retape is required. You’ll probably have nicked it with a tyre lever, or applied it cold.

Its easy to fit the tape, just get it and the rim up to room temp.

You don’t need a mushroom patch.

Valve leaks generally always mean retape is required. You’ll probably have nicked it with a tyre lever, or applied it cold.

My new fave thing is:

Tubless rim tape

Like a rubber band around the rim nice and tight and seems to be less prone to being affected by tyre lever.

Dunno if you get anything like them in the U.K.

Retaping is not THAT hard.

I’ve just used some stuff from CRC and it really lacked any kind of stickyness and it was a bit of a battle of coordination to get a wrap on a 29r wheel single handed but with a couple of layers it gripped enough, then squashed into place with an inner tube for a few hours it seems to have taken well enough and tyre went up easily.

I was also getting a leak by the valve which in my case came from the inner valve hole in the rim having some minor damage so the valve base wouldn’t seal. My thread on this is just a couple of days old if you want to take a look.

Retaping isn’t hard at all tbh. People make it hard for themselves using inappropriate tape or overcomplicating cutting the hole but it is genuinely just these 3 things:

1) clean the **** out of it so the tape sticks. Isopropyl/brake cleaner. Not a bad idea to scuff the rim bed with a scotchbrite pad/scourer to give a better key, but it’s not essential.
2) Stretch the tape on. Otherwise it just sort of sits on top, you want it to conform into the rim.
3) Don’t piss about with the valve hole, just make sure it’s stuck down well to the rim then cut it with a scalpel, just run it around the edge of the hole and it’ll be perfect. (but it MUST be stuck down around the hole or you’ll cut a big mad ragged oval) You hear about people using soldering irons, cutting Xs, all sorts. It’s just a hole.

(4: use good valves. Not necessarily expensive, some expensive valves are crap, companies try to justify higher prices by making them complicated but that’s not better. I use these, they’re ace. Big simple conical plug, can’t really go wrong except on weird shaped rims, literally only ever had them fail on some skinny road rims. https://www.ebay.co.uk/itm/284277160129?hash=item42303d38c1:g:0FYAAOSwtFxb2V4J)

Everything he says ^ there’s nothing difficult about it.

Just one more thing to add to that list: make sure the tape is wide enough. It should go from one wall to the other. If you do that, the seal is formed entirely between the tyre beads and the tape, and it doesn’t actually matter how well the tape is stuck to the rim. It just has to be stuck well to itself where it overlaps.

Make sure your valve suits the shape of the rim. Some rims have a channel and suit certain shaped bungs. But if your valves came with the wheels that shouldn’t be the issue. When tightening the valve, push the bung into the rim with your thumb to get a decent tight seal. But don’t be tempted to use pliers on the nut.

Thanks for the replies everyone. The wheels were complete builds from CRC/Nukeproof, pre taped with valves. Had a look back on my Strava, I think the wheels have been ridden about 10 times in total since I bought them.

Are you sure there is enough sealant in and that it hasn’t dried out? I’d start with a syringe or 2 of Stans and go for a ride.

I’d start with a syringe or 2 of Stans and go for a ride.

Yeah I was going to say that. Even if you didn’t have the tyre off to fix a flat, the tyre could have folded whilst soft and lost a seal.

Unless it’s clearly leaking from the puncture hole, I wouldn’t try patching the tyre.

I’d suggest the extra sealant, but pump it up again to 40psi so you can be fairly sure it’s well-seated. Then ride a bit to slosh the fluid around. Then let some air out until it’s at your normal pressure.

Okay, will try that. Cheers.

As above making sure you’ve a decent amount of sealant in there might solve it but if I had one leaking around the valve hole I’d probably just retape it now. It’s very easy to do. Follow exactly Northwind’s instructions. Personally I buy tesa tape to the full internal rim width, or near enough. Wide tape reduces the chance of you catching it when changing a tyre sometime later.

If you’ve got the tyre off then there’s no harm in mushroom patching your hole, just to make sure. It might be unnecessary but it’s another very easy job for belt n braces and you should buy some mushroom patches anyway. I would do this, then you’ve eliminated the two known issues even if they’re both minor.

All in all tubeless shouldn’t be any harder to live with than tubes, it’s just a bit different and you need some bits. Tape, sealant and repair stuff is about it.

Worth noting that they often do lose pressure over a few days early a tyre’s life. But then after a few rides it settles down and holds pressure very well. If it doesn’t settle down it probably just needs more sealant in there. Don’t scrimp on the sealant.

3) Don’t piss about with the valve hole, just make sure it’s stuck down well to the rim then cut it with a scalpel, just run it around the edge of the hole and it’ll be perfect. (but it MUST be stuck down around the hole or you’ll cut a big mad ragged oval) You hear about people using soldering irons, cutting Xs, all sorts. It’s just a hole.

I just pierce a hole in the tape with a really small screwdriver then shove the valve through it. Works for me!

pdw
Free Member

Just one more thing to add to that list: make sure the tape is wide enough. It should go from one wall to the other.

Or, much narrower. With wide mtb rims you can quite often tape just the rim bed and not the edges where the tyre sits. Means the rim itself has to be airtight- most are, but some cheaper ones aren’t- but it’s more reliable, because the tyre isn’t touching the tape at all, so it can’t damage it/push it off when you change tyres.

You know i said it wasn’t that hard well mines still blasted leaking although I think the damaged rim/valve hole might still be the culprit despite the sealant and washer approach.

Will be taking it apart again 😭 to see if any sign of the tape lifting as I did rush it together so I could go riding. Maybe I need a normal rim tape + a cut up 26r tube if it’s the valve hole.

Still be cheaper to fix than the car I expect.

So, I’m resurrecting this thread. The woes continue, this time on another rim.

On Saturday morning I was due to head out and discovered the new front tyre (Minion DHF) I’d fitted to my Flow S1 on the Reign was flat. I had fitted it a couple of weeks previous and done one ride on it. No problems at all before or during the ride. Anyway, start to pump it up and it’s not holding air. It’s pissing out through the valve. After a lot of swearing I took the tyre off. Valve looked fine, tape looked fine. But in my anger just ripped the tape of in prep for fitting new stuff and a new valve.

I’m not convinced at all. I’ve never fitted rim tape, and no doubt I’ll balls it up.

On the Nukeproof wheel I topped up the sealant. Made no difference. I’m also going to re-tape that one and potentially fit a new valve. But, I have an issue. My Flow S1 has an internal width of 29mm and the Nukeproof is 28mm. Stands recommends 30mm tape for the Flow. Will 30mm tape be okay for the Nukeproof too?

Although to be honest, I’m thinking of going back to tubes. I think tubeless is absolute garbage IMO.

FWIW WTB recommend that tape should be around 3mm wider than the rim internal measurement. It doesn’t have to be ridiculously accurate, you’re ideally wanting a seal between tyre and tape, not tyre and rim. If that’s the case then the only two places it can leak are at the tape join and at the valve hole. The former is dealt with by ensuring a good overlap and that the tape is well stuck down against itself. Fitting a tube for 24 hours can help. At the valve, try to ensure a cleanly cut hole, removing any excess tape (a sharp scalpel helps). Then you just need to ensure a good seal at the valve “bung” by tightening it but not over-tightening it.

Thanks scotroutes.

FWIW WTB recommend that tape should be around 3mm wider than the rim internal measurement

Spec for the Stans Flow S1 shows 29mm internal width and 30mm tape used. So, who is right? Either way, the 30mm tape should cover me for both wheels.

I had issues with my WTB rims until I went 3mm wider than rim width, all fine now.

30mm tape should probably be fine. I normally go a couple of MM wider than the internal rim width. In my case 27mm on a 25mm internal XM421 and 32mm on a 30mm internal XM481. I find the DT Swiss tape goes on nicely although over time the Stan’s sealant seems to take all the writing off the tape.

Just make sure you clean up the rim – I’ve used the B&Q ‘Dial’ decorators wipes the last few times. I then dry the rim off with clean kitchen towel. I start say 6 inches one side of the valve hole and hold it down with one hand whilst stretching the tape down until enough of it is stuck to the rim that I can then rotate it. You really want to be pulling down on and stretching the tape so it conforms to the shape of the rim – getting it molded into any channels. I finish up 6 inches past the valve hole so you have a good overlap on the tape both sides of the valve hole.

I then get a rounded plastic tyre lever and make sure the edges of the tape are well stuck down where they meet the rim side wall. Also go round with my finger and make sure the tape is stuck down into and central channel.

Seems to work for me – I then just stick the tyre on and pop it onto the rim. I haven’t had to leave it overnight with a tube in or anything like that – but some people swear by it and it makes sense it would really push the tape down hard onto the rim.

Thanks all. Will order some of the Stans 30mm tape.

As for other tips, is it easier to do with the wheel still on the bike and the bike upside down, or remove it? I’m not blessed with a wheel stand.

I’d remove it – I started off doing them in a wheel stand but found just having the wheel on my lap whilst sitting on the garage floor worked fine. So I do it like that everytime now.

 I think tubeless is absolute garbage IMO.

ah well, that may be the case…But you’ve started now, so you’ve got two choices…Get it done*, or forever have the thought that ‘if’ you could just get it up and running, it was be amazeballs…and if you don’t do it, that tape and sealant will be there…on the shelf waiting for you every time you open the shed door…waiting…

*because…How hard can it be goddamnit!!

As for other tips, is it easier to do with the wheel still on the bike and the bike upside down, or remove it? I’m not blessed with a wheel stand.

Whatever you feel comfier doing, I remove the wheels, clean them, leave them in the house overnight with the tape so that they’re warm and then fire away, tape adheres much better if it’s not cold. As SR rightly says, a tube in there overnight will also help.

Anyone got a link for mushroom patches. Can only find car, moto ones. Thanks

FWIW I always overlap opposite the valve. No particular reason other than I think it might be easier to get a good cut/seal when there’s only one layer of tape to go through.

@teamslug I’ve only ever just bought 3mm ones off ebay, never really paid attention to recommended uses.

My new fave thing is:

Tubless rim tape

Like a rubber band around the rim nice and tight and seems to be less prone to being affected by tyre lever.

Dunno if you get anything like them in the U.K.

The nearest thing to this, that I know of, is the Bontrager rim strips.
The rims, strips, valves and tyres are designed as a complete system, so there is no guessing whether your rim/tyre combination will work or not.

Admittedly, this doesn’t allow for the range of tyre choice that most people crave but, for my modest skills and riding, I’ve found them to be faultless for road and MTB

These are what we have used for years 3mm, you will also need some glue

3MM SMALL HEAD PLUG PATCH MUSHROOM

https://www.ebay.co.uk/itm/131208504777?hash=item1e8ca2e5c9:g:nJYAAOxymmJTkHmO

As for other tips, is it easier to do with the wheel still on the bike and the bike upside down, or remove it? I’m not blessed with a wheel stand.m

Remove the wheel.

Shut down.

Hold the wheel vertically between your legs.

This way, you can put a bit more tension on the tape as you apply it. I spin the top of the wheel away from me, pulling the tape towards me as it unrolls, stretching it and pressing it as deep into the well of the rim as I can. Once fitted I then follow up with the end of a rounded tyre lever, pressing the tape into the beads

So… attempt number 3 at taping my wheel. First couple of attempts and I was getting too many folds and creases. Think I have managed better this time, only taping a few inches at a time. There are still a lot of small air pockets, but no creasing.

I also found that the valve on my rear wheel of the other troublesome wheel seems to be damaged. I think the o-ring is gone and that is where it has been leaking.

Should the O ring be inside or outside the rim?

It’s a Nukeproof tubeless valve. It appears to be on the outside of the rim from what I removed, underneath the valve nut.

I’m thinking about using a Stans No Tubes valve instead of the NP one. Is there any reason why this wouldn’t work?

As long as your hole is round a Stan’s one should fit. I’ve found the nicest valves I’ve used are Rimpact ones to be honest. Followed by DT Swiss then stan’s.