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2

Just in case you prefer general knowledge over physics: the density of air at a reasonable temperature is around 1.2 kgm-3. The volume of your tire (accepting Tom77's answer) is 0.000959m3. So the mass of air in it at 15°C and atmospheric pressure is around 1.1g. Then we do need one bit of physics, the relationship between mass and pressure for a ...


4

To calculate the weight of a gas you need the volume, pressure and temperature. A bike tyre is a torus (doughnut) with volume given by the formula: V=(πr^2)(2πR) where R is the radius of the wheel and r is the radius of the tyre. For a 700c25 tyre, R will be 311mm and r will be 12.5mm that gives a volume of 9.59×10^5 cubic millimetres or 0.000959 cubic ...


8

The ideal gas law (which is a good approximation in this case) says PV=nRT where P is pressure, V is volume, n is mols of gas, R is the ideal gas law constant, and T is temperature in Kelvin. Thus, solving for n, we see n = (PV)/(RT). Then, assuming air is made up of {gas1, gas2,...} with fractions {p1,p2,...} (so p1+p2+...=1) and corresponding molar ...


2

There's a very simple way to accurately estimate this: use Boyle's gas law which states that the product of pressure and volume is constant. Thus if the air volume in your tire decreases by 10% (which I think is a huge overestimate), then the new volume V2 is 0.9 times the old volume V1. Hence the new pressure P2 must be 1/0.9 = 1.11 times the old pressure, ...


4

As a first approximation you could use zero. But more accurately, with a 23mm tyre you probably have about 20mm diameter of air inside. A 700c wheel is ISO 622, so has an inner radius of 311mm. So your tube forms a torus with major radius 321 and minor radius 10mm. A litre is a cubic decimetre (a cube 1/10th of a metre or 10 cm on a side) so it's easier to ...


4

I'm sure it's possible to calculate this but my bike was only a few steps away so it seemed easier to just measure the pressure change. I connected a floor pump with a pressure gauge and pumped the back tire to 100 psi on a 700x23 tire. I then sat on the saddle and watched the pressure gauge. It didn't move. I stood up and tried a second time with the same ...


4

From Tom J. Stokes excellent article on choosing tires: Wider tires tend to grip better during cornering and over rough terrain, at the expense of increased rolling resistance and weight. Wider tires will also float better in sandy conditions and are much more resistant to pinch flats when riding over sharp rocks or off of drops. For moderately rocky ...


0

Beware of tyres claimed on-line as having a Kevlar Belt in them. They may have just Kevlar particles blended into the tread compound to reduce wear. Maxxis Refuse is a tyre that has K2 on the tyre sidewall and a statement on the packaging/material/label that comes with the tyre as stating a Kevlar Puncture resistant Belt. I have been using Vittoria tyres for ...


0

On a cyclocross/hybrid commuter I'm running Continental Contacts, and they have been decent to good. (running 700x28's) https://www.conti-online.com/www/bicycle_de_en/themes/city/Allround/CONTACT_en.html Because of the wear I'm thinking of switching to Top Contact II's. Pretty spendy tho. Disclaimer I have a 'trekking' bike tire bias, In general I'm not ...


3

Based on your edit, do this. Remove the wheel, deflate to about 10 PSI, then roll it along the ground, pressing down hard, for several revolutions. After you've done this examine the strip. Anywhere where the strip is not showing the "average" amount, tug on the tire to pull it out. Anywhere where the strip is showing too much, first examine the opposite ...


1

Potholes cause impact punctures (also called pinch punctures or snakebites) when the force of an impact is sufficient to compress the tyre all the way to the rim. Options to reduce the risk: Increase tyre pressure Reduce impact energy by reducing weight or reducing speed Use larger tyres, which would increase the distance between the rims and potential ...


0

As far as I know, the line that you are seeing is indeed an indicator if the tire is properly installed. It doesn't matter how much it is showing. What is important is that it is visible. If the indicator is showing too much somewhere, it will be hidden under the rim on the opposite side of the rim (opposite passing through the diameter). This would be an ...


3

The visible strip sticking out from the top of the rim and inside the line is in fact the Chafer strip. This is on the tire to prevent the bead hook on the rim from cutting into the tire. The bead is the wire or in the case of folding tire such as the x'plor ush Kevlar ring on the edge of each tire. When seating the tire the bead is place inside the bead ...


0

From my own personal experience on a paved road, I found that I am generally a lot faster on my road bike when the tires are inflated to maximum pressure. I found that a lower inflated rear tire slows be down by as much as 11 minutes on a 15 mile ride. But I must add, that I was riding with a tailwind on my way back with the inflated tire. Nonetheless this ...


1

Offhand, that bike looks pretty good for your needs, aside from the front suspension and the 32H wheels. The tires are good and wide, and if you keep them well inflated (above 4 bar) they should handle your weight OK. The front shock has lockout, so if it sags too much you can just keep it locked most of the time. Of course, you will be stressing the ...


3

According to the people at Scott, the general weight limit for a rider is 110 kg. You are significantly above this, so the manufacturer doesn't necessarily support you on that. The wheels durability depends a lot on who built them and how well they were built and if they have taken any damage. You are in a YMMV (and at your own risk) range by sticking with ...



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