Tubeless tyres question.

[xerxes]

This is my first try with tubeless tyres and they're road tubeless, 700 x 40c; both the tyres and the rims are designed for tubeless.

I can get the tyres on the rims without any problem and I was then able to pump them up using just a track pump, no need for a special air tank or a compressor. The tyres then make some fairly alarming popping noises as they seat into the beads.

I pumped the tyres up to about 60 psi, but they don't stay up for long and will go flat in about an hour or so.

This is all without using any sealant, just mounting and inflating the tyres "dry". My question is, is this normal, or should the tyres stay inflated for longer, even without any sealant?

 

[d8mok]

Re:

You need to add the correct amount of sealant and then use a compressor or air tank. Even though you think it’s seated correctly there will be small places it’s not popped into place. I’ve never done a road bike but I always inflate my mtb tyres to around 60psi and leave them overnight and then drop the pressure accordingly. So I would assume you also need a bit more pressure than 60psi.

 

[jimo746]

Re:

What rim tape have you used? Or is the rim/spoke bed already sealed somehow?

It may be that once you add sealant and pump the tyres up the sealant will help to seat the tyre bead and fill any tiny gaps between tyre/rim, and the tyres will stay inflated no problem. I often find another layer of tape on the rim helps to make the tyre fit tighter, at the expense of needing a tyre lever to mount the tyre.

As already mentioned you might try inflating to higher pressure initially to help seat the tyre bead fully. The twangs and pops are quite normal as the bead pops into place, it takes some getting used to though

Also check the tyre valve is seated correctly and tightened, or you'll get air leaking past it and the rim.

It sounds like you're 90% there tbh though.

Edit: to answer your question at the end of your post.... It's not unusual. I've had tyres set up "dry" that stay up overnight, and others that have deflated after 4 or 5 hours. 99% of the time adding sealant and/or more tape is the answer.

 

[xerxes]

Re:

What rim tape have you used? Or is the rim/spoke bed already sealed somehow?

The wheels came set up for tubeless, with rim tape for tubeless already fitted: https://www.huntbikewheels.com/collecti ... eep-24wide

The tyres are Schwalbe G-one Allround TL-Easy, also designed to be run tubeless: https://www.schwalbe.com/en/road-reader ... round.html

On the Hunt web site it says:

* Maximum tyre pressure for this rim is 120psi when used with an inner tube and 100psi when running the wheel set-up tubeless. 100 psi is more than enough for any rider on road.
* Maximum tyre pressures for other tyre sizes 30mm do not exceed 80psi, 33mm do not exceed 60psi and 35-45mm do not exceed 40psi.
* Please do not exceed the maximum pressure stated on your tyre.

The maximum pressure for this Schwalbe tyre width is this is 70psi.

When I inflated them, I stopped at 60psi, above the maximum of 40psi for this rim - tyre width combination recommended by Hunt.

Should I go a bit higher, just for the purposes of seating the tyres, then reduce the pressure to the actual "running" pressure?

 

[jimo746]

Re: Re:

Should I go a bit higher, just for the purposes of seating the tyres, then reduce the pressure to the actual "running" pressure?

That should be OK briefly, to ensure the tyre bead is seated.
Soapy water, or a bit of sealant on the tyre bead often encourages things to seat nice and easily.
The idea of using a compressor etc is to provide a sudden burst of air to suddenly "pop" the bead into place. But I've had success with only a track pump in the past too, and that was with a "ghetto tubeless" setup.

If I were you, I'd just put some sealant in there and pump them up again. Move the wheel around/up /down to move the sealant around inside the tyre, you'll probably find that and tiny air gaps will be sealed up, and the tyre stays inflated.

 

[xerxes]

Re:

OK, thanks.

I think they're going to be OK, but I'm going to wait before adding the sealant. Apparently it goes off over time, so I'm going to wait untill I'm all ready to go, before I use it.

Frustratingly, I have a set of wheels, tyres, handlebars, a box containing an entire groupset and all the other bits and bobs to build a bike, but no frame.

Frame will hopefully be arriving at the end of the month.

 

[jimo746]

Re:

The sealant does dry up, but it can take months/years depending on use/storage/riding conditions.

This afternoon I swapped over the tyres on my Gravel bike, removed the 650x33 cx tyres I'd used over the winter, and fitted 650x47 semi slicks.
I emptied the sealant from the old tyres into the new tyres as it looked OK (had been in the tyres since start of November), topped it up with some fresh sealant (bigger tyre volume), inflated the new tyres, heard a bit of a hiss from somewhere around the rim, shook wheel around for a minute, and the hissing had stopped.
Just checked and still holding pressure fine

Proper tubeless tyres and rims make it so easy. It honestly took no longer than swapping over tyres with tubes in them tbh.

 

[mattr]

TBH, you really need to get some riding in to get the sealant into all the nooks and crannies properly, so if you know it all goes together, probably best leaving it for now.

 

[shedobits]

Re:

+ 1 re using washing up liquid to find from where air is escaping. I use a paintbrush to add it between the tyre and rim so that it works as a lubricant and so get a better seal. Also after adding the sealant try "sloshing" the wheel from side to side as well as spinning it. Leaving the wheel flat on a bucket or bin for half an hour each side works too and should resolve any poreousity issues with new side walls.

Because of the high temperatures here sealant can dry out quickly so I refill every three months in the summer and every six months in the winter. Sadly I keep a log so that no wheel gets missed.:roll: On the plus side apart from a torn sidewall I can't remember my last puncture, certainly its been some years, (I may regret writing this).

Any way enjoy tubeless life.

 

[clubby]

Sounds pretty normal to me.
I wouldn’t up the pressure anymore, 60psi is plenty to seat a 40c tyre.

Set up a pair of G-One bites a few weeks ago and they were a doddle. Like yours they went up with a track pump then went slowly down after an hour. This is beacause the sidewall of the tyre is porous and needs the sealant to seal the small holes. Bead leaks tend to cause the tyre to deflate a lot faster.
As Jimo said, the sealant lasts ages, have changed tyres after a year and still had liquid in it.
If I were you I’d pump them up as you have to seal the bead. Then deflate, remove valve core and add sealant through the valve. Clean inside valve with cotton bud and fit greased valve core. Sounds like a faff but you’ll thank me when you next need to remove it. Pump up to 60psi again and shake then spin the wheels to distribute the sealant into all the knooks and crannies.
Leave overnight then check pressures.