Tubeless.... Help me out!

[simon the viking]

Recently (this year) gone tubeless on 2 of my bikes. The Gravel bike settled down (alloy rims) quite quickly and now only needs pumping up around once a month.

The road bike on carbon wheels seems to go totally flat in 48 hours. The bike shop said the gunge will find all the porous air holes over time and stay up. After a couple of months (although not ridden excessively due to horrid weather) it's still going flat.

What pressures do people run on 28c tubeless tyres? I'm pumping them to rock hard like inner tubes. Is this correct? Or should I run them slightly softer for a few weeks.

Or should I admit defeat and stick tubes back in?

 

[Sea of vapours]

'Rock hard' is not what you should be aiming for really. Try the Silca tyre pressure calculator:
https://silca.cc/pages/pro-tire-pressure-calculator
There are several others, but Silca's figures tend to favour performance over comfort more than most so they won't be as much reduced from 'rock hard' as the others, probably.

That said, they shouldn't be going totally flat in 48 hours so there is something amiss there. I check / pump my tyres each ride, but the loss is more in the range of 1-2psi over a couple of days, from around 60psi on 28mm 700c tyres.

 

[Ian H]

I have two tubeless equipped bikes. the Panaracer 38mm tyres stay up to pressure for weeks; the GP5000 25mm ones lose significant pressure over a few days, but they won't go totally flat for a several weeks. I run the latter at 70/80 psi.

I top up the sealant when I notice the pressure dropping more rapidly, or after loss due to a puncture.

Pressure-retention does improve after riding and a top-up of sealant.

 

[simon the viking]

Thanks for the answers so far. I run at around 70psi. Think the answer is to ride it more... If the rain stops.

 

[13 rider]

Do you top up the sealant at any intervals ? , I presume if it sits unriden so the sealant isn't sloshing around I'd guess it my dry out quicker ? Just my thoughts , My regular ridden tubeless do lose pressure but no where near the rate of yours ,I perhaps pump them up once a week ,
As for pressures it is amazing how low you can go ,but ideal pressure depends on rider weight ,I run 65psi at 70kg but have gone as low as 50psi but it just felt a bit too squishy

 

[wafter]

Thanks for the answers so far. I run at around 70psi. Think the answer is to ride it more... If the rain stops.

Yeah, the higher the pressure the more leak-prone it will be / the faster it will leak.

I only have a little experience in this area but have found that sometimes air retention follows a reverse exponential curve; with rapid air loss to start that tails off with time and use.

Do bear in mind that while riding distributes the sealant, as soon as you stop it'll all run down to the bottom, leaving most of the tyre unprotected. It may be that you have one or more particularly pernicious slow-leaks that just happen to be not-at-the-bottom of the wheel when the bike is stored.

If you can be arsed I'd advise removing the affected wheel(s), pumping them up to max pressure and covering with (maybe soapy) water. Watch and listen for bubbles, mark the tyre where the leak is and orient the assembly so that the leak is covered by sealant, which should bring a satisfing end to the noise as the sealant reaches the leak.

On council tubeless I've often found the biggest culprit to be the interface with the rim at the bead, although consider that leaks can also occur at the tape and valve/rim interface; which will manifest as bubbling from the valve hole as this is the path of least resistance. Also consider that by default sealant is going to gravitate towards the outer circumference of the tyre, so if you have a (recoverable) leak at the tape / valve you'll need to make more of an effort to get sealant to that area; either by over-filling so it's submerged at the bottom of the wheel or

Once you have all the leak points marked on the tyre it'll be easier to apply a drop of water in isolation to them to check for ongoing leaks. Fill the tyre to a known value and check it a day later, hunting for leaks. Repeat; perhaps graphing the results in a spreadsheet so that a loved one can print out a copy and put it on the fridge. Don't forget to label your axes.

HTH!

 

[Venod]

Can't help with the leaking air, but don't have them rock hard, I run my 28 tubeless at 60 psi rear 55 psi front, I weigh about 11 stone.

 

[geocycle]

I have my 28 mm at 65/60 psi. They go down to 55/50 psi after a week which is a bit irritating but I’ve got used to it. These are Schwalbe pro ones.

 

[Dogtrousers]

What pressures do people run on 28c tubeless tyres? I'm pumping them to rock hard like inner tubes. Is this correct? Or should I run them slightly softer for a few weeks.

I use tubeless Pirelli Cinturato Velo 28mm tyres on DT Swiss alu rims. I use about 70-90 psi (5-6 bar - my track pump happens to be graduated in bars, so that's how I roll). I think 5bar is the minimum printed on the sidewall. Something like that. Doesn't lose noticeable amounts of pressure but I only ride the bike once a week and always top up the pressure before use (always have done, whether tubed or tubeless) so I don't notice it.

Sorry, can't really help with your specific problem.

The only time I pump tubeless up rock hard is when mounting new tyres. I do this because I think it will help ensure the beads are pushed properly in place. But that's my theory and it might be cobblers.

 

[simon the viking]

Update as OP...
Going back to tubes on the 28c....Doing my tree in!

Leaving gravel bike on tubeless as they stay up

 

[T4tomo]

Don't forget to label your axes.

No need, easy to get apart: Your front one will be 100mm OLN and the rear 130 or 135mm OLN depending on the type of bike. *other OLN's exist.

You're

 

[wafter]

No need, easy to get apart: Your front one will be 100mm OLN and the rear 130 or 135mm OLN depending on the type of bike. *other OLN's exist.

You're

Axes

 

[T4tomo]

Axes

bloody L

 

[C R]

bloody L

Axels?

 

[T4tomo]

Axels?

View attachment 733103

Fail.
Axl