[Closed] tubeless explained

Personally don't believe in really low pressure. Proper ust tyres are a lot stiffer than a normal tyre.
Main advantage is more puncture resistance, but you can still puncture them..

this exact same tyre was completely softer with a tube. Hans dampf tubeless ready

I can't say I have ever experienced the phenomenon you describe, and to be honest it doesn't make any sense.

What on earth are you on about pitchpro?

The accuracy of the human body as a calibrated measuring device never ceases to amaze me.

ok I haven't converted my front tyre to tubeless yet so I'll let it down to 25psi and take a picture of the difference.

Many thanks for the 'clear' explanation!

OP you do know the only thing "special" about "tubeless ready" is a slightly thicker rubber around the bead to aid sealing.

Well, that's tubeless cleared up.

NEXT!

The accuracy of the human body as a calibrated measuring device never ceases to amaze me.

😀

[i]Almost[/i] made me chuckle, but not quite... Elicited a genuine wry smile though! 😉

35 PSI in a larger volume will feel a lot harder - see your cars tyres.

I fancy a share of all this derision, so I'll admit to having noticed this phenomenon too. Nothing to do with the type of tyre, purely a difference between the 'thumb feel' of a tyre when run at a similar pressure with and without a tube.

Not sure it 'explains' tubeless though.

Less boingy more squidgable and at least 13.4% squirmirisation.It's pretty obvious to anyone.

35 PSI in a larger volume will feel a lot harder - see your cars tyres.

Think you might find thats more to do with the car tyre being a 4 ply and a bike tyre not. 😉

Think you might find thats more to do with the car tyre being a 4 ply and a bike tyre not.

Mebbe but IMO the OP is right in that the exact same tyre feels significantly harder tubeless at the same PSI. What's your explanation for that? I asked about this ages ago:

http://singletrackworld.com/forum/topic/you-know-when-people-talk-about-psi-numpty-physics-question

What's your explanation for that?

I don't have an explanation for something that i've never experienced myself.

I have noticed how much better a tyre feels when ridden tubeless though.
How it feels to the touch of my hand is irrelavent. 🙂

the guys i ride with who run low pressures before didnt notice. i ride high pressures normally and certainly notice. i wouldnt even dream of riding 25psi before. always some smart ass ready to scoff at a comment. i eat a steak not poke it but i sure as hell poke it to check its done.

Tubeless explained.......

Tubeless, no inner tube .

None tubeless, has an inner tube.

Hi
Pitchpro2011, friends you ride with???? Either your being completly honest or your friends have the patience of saints because you must bore them sensless with all your mindless dribble?!?!?!

Have you ever heard such cr$p come from one person and what's all this about poking a steak!!!!!!

It's been entertaining that I agree.

Sorry *Either your "NOT" being completly honest

used to run 40-45 on rear.

is this your road bike?

I run the same pressures as when I ran tubes (35 rear, 28 front), but there's definitely more grip. Never been interested in that low pressure thing, don't like the "squirming on the rim" feel.

pitchpro2011 - Member

in short low pressure in a tubesless tyre is at least as firm as 10psi more with tubes.most here will already know this

Nope.

I've noticed the same phenomenon using the same tyres - just converted to tubeless - to get the same amount of squish (eg similar contact patch size) when riding, I dropped from 40psi to about 20-25.

My idea (and I haven't really spent the time thinking it through in great enough detail to say that it's the right answer):

An innertube is elastic and when pumped up inside a tyre, is stretched. As such you have a certain amount of pressure in the tube just to get it to fill the tyre.

You don't have that with tubeless - the air always acts directly on the tyre and isn't being compressed by anything (until you sit on the bike)

So, however much pressure it takes inside the tube to get it to expand to fill the tyre is the difference.

Maybe 🙂

Your squeezing a different tyre.

Its different because its made differently, you know, to hold the air in without a tube.

So of course it "feels" different. Its probably got a thicker sidewall, probably because it has to be air proof.

I've noticed the same phenomenon [b]using the same tyres[/b] - just converted to tubeless

You spent money on it, of course it feel better 🙂

Or can someone provide some science ?

I tried to above. I'm waiting for someone more bothered than me to say whether it's actually right 😀

(FWIW, I don't think tubeless feels better. I just don't get pinch flats and punctures seal themselves)

clubbers explination sounds plausible - but...

it definately doesnt take 15-20 PSI to expand a tube to the shape of a tyre which is the difference we're talking about (unless your using a racing bike tube!)

and

even if it did take say 15psi to just touch the outer wall of the tyre - if you push your thumb into the tyre you would still feel 15 psi worth of resistance from the tube(Not 0 PSI as would be required for this to explanation to be correct).

next....

Yeah, I did realise that was a flaw but it's the only explanation I could be bothered to come up with 😉

Without the tube you are pressurising a slightly greater volume. The tubeless setup should therefore feel slightly [u]softer[/u] at a given pressure, but you must have had your thumb recently calibrated to pick up on this.

what about all the sealant - that takes up volume.

That makes no sense, you let the tyre down until it "felt" right?

[img] [/img]

A tyre (well more specifically the air in it) is basically a spring.

By taking out the tube and running tubeless you are removing resistance (rubber) from the spring so it will feel plusher for a given spring rate (pressure)

in case you haven't noticed the clowns giving me shit are the guys I ride with. clearly alot of people notice this ,however, they always dismiss my opinion as nonsense despite having a combined iq of 50. 😉

I just bought a ceramic and titanium headset.... which they scoff at even though the expensive shit bearings they just bought broke within 2 weeks.
much love you tossers xxx

This thread desperately needs someone with a full grasp of physics.

I am not that man. However, I am a man who says tubeless is rubbish and a faff.

simple really when you think about It.....take 2 things exactly the same but in extreme to highlight...... a brick and a flat piece of wood weighing exactly the same. The wood even though being the same weight and force will offer more resistance from sinking in a swimming pool because the surface area is greater....the volume is greater. in the tubeless tyre there is a larger surface of air pressing against a flat surface.

However, I am a man who [s]says tubeless is rubbish and a faff.[/s] doesn't have a big enough track pump or a bottle of Fairy.

😛

So, can anyone explain| did this retard fill his tyre with bricks or wood?

Hans Dampfs are nice?

Sighs at lack of elementry physics, wood is generally less dense than bricks that's why it floats, some woods do not float.

When something like a log of wood is put into water, it pushes down on the water and the water moves aside to make room for the object. When there is enough water to push back up against the object with the same force as the object is pushing down, then the object will float!

That’s why a piece of wood that is lightweight for its size will float in a big body of water, like the ocean or a river. However, that same piece of wood might not float in a different smaller body of water.

How much pressure does it take to inflate an inertube to the size of a tyre? 10 psi or so.......

......but that's elastic deformation.

Strangely I was just thinking about going tubeless today..... like STW is reading my mind......
I was going to cut off some old presta valves from some tubes and use an o-ring and the nuts you use to keep the valves in place to seal it. Any reason it shouldn't work?

fourbanger - Member

How much pressure does it take to inflate an inertube to the size of a tyre?

An amount too small to register on any gauge I have.

Any reason it shouldn't work?

You wanted to build a spaceship, so you ran out of Fairy, or don't have a big enough pump.

Or you chose Maxxis eXception tyres.

An amount too small to register on any gauge I have.

ohhh.... magic then.

there's a big thread on mtbr about tyres and rolling resistance, a german mag ran tests and tubeless setups had significantly less rolling resistance than tubed, they found the biggest factor in rolling resistance was the carcass construction not the tread or volume.
maybe having a tube in there affects the carcass in some way.

fourbanger - Member

ohhh.... magic then.

Rather, gauges not designed for reading small amounts. But I guess sufficiently unadvanced technology can be indistinguishable from magic 😉

However, I am a man who says tubeless is rubbish and a faff.

Hmmm, strokes chin with wary expression, not quite sure if Waderider is being serious or is coming the **** on this one.

I've rode wi tubeless since 2007, i say "rode" but as i sacked off the bikes completely for a few years i really have only rode for a couple of those years but they have been rode tubeless, mavic slr's and stans with absolutely nae faff, nae trouble, and most importantly i have never had a puncture so never carry a tube nor a pump, nor a puncture repair kit.

Tubeless rocks a fat one, i'll never run a mtb wi tubes ever again.

Run tubeless more because for convenience than ride quality. Fingers crossed for never having to fix a puncture again!

this is nothing to do with floating you absolute fool. wood floats because of the air pockets inside. I'm talking of equal force against a small area and then over a larger area. read a science book..... you too shep

Wood floats as its trying to get back to land. Trees grow on land.
Bricks sink as they are made of stuff and being in water makes them turn back to stuff.

>nae faff, nae trouble, and most importantly i have never had a puncture so never carry a tube nor a pump, nor a puncture repair kit.<

Out of interest - do you ever ride solo, literally hours from any kind of assistance?

I think the OP does have a point.

I'm yet to go tubeless but I can see there will be a change. The tyre may deform less as how often do you think an inner tube will match the exact shape of your tyre and chosen rim? There will be some voids where only atmospheric air pressure will exsist and thus when you sit on your bike you're effectively pushing the inner tube info the rim. Where as in a tubeless setup the pressure should be the same everywhere inside the tyre.

So partly to do with volume of air and also partly to do with the fact the entire tyre/rim is filled with no low pressure zones.

That's my take on it.

^. This ^

An inner tube wil not exert equal pressure on all parts of the tyre, due to a mismatch in the exact shapes of each, and there will be a small void near the beads also.

With no tube, the entire tyre volume is at equal pressure.

Whether this produces the phenomenon described by the OP I dont know, but it does make sense.

I ride tubeless for the puncture resistance, not weight/rolling resistance/lower pressure. So far, no punctures in 2 years. I had one burp, mainly due to being lazy, and not pumping up a tyre I knew to be WAY down on pressure, and riding it on a steep rooty descent.

now someone makes sense. this sounds fully reasonable.

The different rolling resistance is due to the difference in the tyre construction.

The tubeless one is different to the tube one, it has to be to be able to work. Its airtight for a start !

Many people use the same tyres with or without tubes so there's no difference in construction.

Out of interest - do you ever ride solo, literally hours from any kind of assistance?

As I stay in the arse end if nowhere, deepest darkest Galloway which is one of the most sparsely populated area in Scotland I always ride solo coz I'm a 100% antisocial cyclist (not ashamed of it). I head out into the hills for hours at a time by myself and if something happens its up to me to get out of it but now't serious has happened yet, apart from a compound fracture of my arm/elbow yrs ago but that was manageable. I guess I could wear a camalbak wi a multitude of spares inside but I prefer to ride light wi a water bottle or two and a teeny pedros seat pack, if I run out of water there's any amount of burns to fill up from. As kids in Argyllshire in the 80's we'd ride for miles n miles with only a pair of shorts, trainers and a t shirt riding quite dangerous terrain as I look back now and nothing terrible happened to us then so all this kit I see folk carrying at trailcentres is rather amusing, massive packs stuffed to the gunnels wi all sorts but if you need that comfort zone to ride with then it obviously works for you, I just prefer to carry nothing as I'm perfectly comfortable doing so. I was always brought up in the middle of nowhere as a kid so I'm very comfortable wi it, it may be different if I was brought up in city or urban environment .

 

Many people use the same tyres with or without tubes so there's no difference in construction

Yes, but the tyre must act differently, in terms of deflection etc. when tubed as there is the interface of the tube pressing on the tyre carcass to consider....

 

OK............................... ?

Over to Somafunk then for a completely different topic 🙂

(TBF this one was not actually getting anywhere)

clubber - XC Jeyboy

Many people use the same tyres with or without tubes so there's no difference in construction.

Mmm. Just because you can use a non-tubeless tyre as tubeless, doesn't mean there's no difference in construction!

Pretty sure they meant that a lot of people going tubeless will do so with regular tyres and thus their experience won't be based on differently constructed tyres but purely on how the same or similar tyre works with/without tubes.

zippy, I'm confused; what about a wooden boat carrying bricks?

And what happens to the water level if you take a brick out of the boat and drop it into the water?

And even more complex, what if there's an aeroplane on the boat trying to take off from a conveyor belt?

FWIW, I've got wood.