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.

[/quote] 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.