Tubeless question
- Thread starter Baldy
- Start date
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Sea of vapours
Guru
- Location
- Clapham, Yorkshire Dales
That's probably fine.
The sealant manufacturers each have their own recommendations on the volume of sealant to use, and that varies according to the size of the tyre. If it's a typical, 700c road tyre of around 28mm width then the volume recommendation will typically be 40-60ml, and 8-9mm measured when dipped is probably that sort of amount. Plenty of sealant manufacturers say that their sealant will last six months.
The sealant manufacturers each have their own recommendations on the volume of sealant to use, and that varies according to the size of the tyre. If it's a typical, 700c road tyre of around 28mm width then the volume recommendation will typically be 40-60ml, and 8-9mm measured when dipped is probably that sort of amount. Plenty of sealant manufacturers say that their sealant will last six months.
ktmbiker58
Senior Member
Should be fine at that level, if you don't use the bike for a few months you may find the sealant pools and congeals into a sticky puddle, in that case I just pop one bead off the rim and wipe/pull the offending slime out and reload with fresh sealant.
figbat
Former slippery scientist
- Location
- South Oxfordshire, UK
I just shake the wheel and judge how sloshy it sounds. If it’s not sloshy enough I add some sealant. If it’s been a long time since the tyre was mounted I might pull it off, clean it all up and put a fresh charge of sealant in. I rarely do that though.
88robb
Regular
- Location
- Netherland
That's plenty of sealant, you're good to go. No need to top it up yet. Check it again in another 3 months.
Dogtrousers
Lefty tighty. Get it righty.
I've never successfully managed to "dip" a wheel to test sealant depth. What did you use as a "dipstick"?
I generally unmount the tyres and have a peek inside. Either every 6 months or so, or whenever the fancy takes me. Also, I generally use about double the recommended amount of sealant. (No valid reason, just vague thinking that more is better)
I generally unmount the tyres and have a peek inside. Either every 6 months or so, or whenever the fancy takes me. Also, I generally use about double the recommended amount of sealant. (No valid reason, just vague thinking that more is better)
Some time ago I found an ultralight titanium tent peg. A bit like a granny's hat pin. Just the right diameter about 2mm.
Ming the Merciless
There is no mercy
- Location
- Inside my skull
How often it needs topping up depends on how hot it’s been in my view. This summer hasn’t been too bad for longevity of sealant
Sea of vapours
Guru
- Location
- Clapham, Yorkshire Dales
Pipe cleaners work well as they absorb sealant and it's thus obvious where the level is. (And no, it doesn't soak upwards, at least not in the 'couple of seconds' timescale I leave it in the tyre.)
They also work well to smear a tiny amount of oil on the inside of the valve, when the valve core is out, to discourage sealant clogging it, and equally well for unclogging it when the oil thing hasn't been 100% effective.
Ajax Bay
Guru
- Location
- East Devon
Maths suggests that if the dip was 8mm, the internal 'height' of the wheel was (311+40)mm and the effective internal tyre width was 38mm then you have ~30ml of sealant left in the tyre. Please consider this entirely irrelevant info compared to the comprehensive practical advice above from riders who know what they're talking about. (See also "how sloshy", "take a peek inside")
Not detracting from your great tips above, but unless I have screwed up the maths, a dipped 8mm depth in 622-28s suggests ~17ml liquid 'left'. Whether that's 'enough' is way above my dry tubed orbit.
Dogtrousers
Lefty tighty. Get it righty.
@Ajax Bay I applaud your maths (assuming you have it right, which I don't doubt). One complicating factor is that sealant is quite viscous. So only some of it will pool at the bottom of the tyre. The rest will hang around sticking to the sides of the tyres & the rim. So you'd need to account for that. And how much has drained into the pool would depend on how long the bike has been standing. I foresee the need for quite a complex model.
I think that, basically, as long as there is some liquid in there, then things are not bad. If it has all dried up, things are bad
I think that, basically, as long as there is some liquid in there, then things are not bad. If it has all dried up, things are bad
Sea of vapours
Guru
- Location
- Clapham, Yorkshire Dales
As @Dogtrousers says, there will be sealant in the tyre which is not in the pool at the bottom, of essentially unmeasurable quantity. My method for deducing how deep the pool should be in a 28mm tyre (about 10-12mm when freshly replenished being the answer) was to measure it after installation of a new tyre and the 'correct' quantity of sealant, and after a fair bit of shaking of the wheel followed by a few minutes settling time.
I initially did that to measure how much sealant was 'lost' when a tyre was new. i.e. stuck to the inside of the tyre, filling pores. The answer to that was 'not really much at all and not worth worrying about'. i.e. the difference in dipped depth between a) the new sealant, poured in carefully and into a pool and b) the same but with shaking and leaving to settle, was negligible and not reliably measurable by me with a dip stick.
Interesting, but I was only after a rough way of guesstimating whether I need to top up or not. Far to many variables, like what's the internal cross-sectional profile of the tyre, for my simple brain to work out. I'll stick with leaving as it is for now, I can dip it again a couple of times over winter and see how/if it changes with time.
Thanks to everyone for your input/help.
