So with the first law of thermodynamics intact because Energy and Work are the same on both the Input and Output side, we can see how the Force must be increased on the Output side for this to happen. In practical terms, the magnitude of Force is enhanced with distance.

On the other hand it increases the stress on the sidewall of the tyre. Mountain bike tyres are designed to take this extra stress but road tyres are not. The former is ‘fractional’, the latter ‘decimal’, and as a rule decimal and fractional tyre sizes that look the same are not.

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The ideal relationship between tyre and rim section is about 1.8 to 1, but any tyre from 1.4 to 2.2 times should fit – always provided that the bead diameters correspond. Nowadays almost all rims have hooked flanges (required to retain folding tyres) that will hang onto tyres up to three times their width. This increases the cushioning effect: you get more comfort out of the same tyre at the same pressure when you fit it to a narrow rim – yet it still rolls just as easily. Same Current: At the same current as the Q100 spun the 28x12 to WOT, the StinGR with the 28x13 C2E develops a 14.89% higher pitch speed while developing 27.21% more power at the shaft. As with the lever in the image below, if there can be no net gain in Work or Energy from the Input to the Output side, then the Force MUST me greater on the Output side. It is confirmed that the gear reduction unit is operating at about a 90.09% efficiency, which is at least 14% more efficient in terms of RPM/Amp with the same prop load than the non-geared outrunners I've tested so far - 142 combinations of motors and props. This also means 14% more flight time on the same batteries from the 14% fewer Amps at the same power at the shaft.

Electrical power systems have always been efficient, and none-geared 3-phase outrunners can deliver as much as 45% more efficiency than gas engines. Additionally, gear reduction units can deliver as much as 15% more efficiency than a non-geared 3-phase outrunner. Since late 2018, I've been involved with the R&D of an electric power gear reduction unit that can deliver comparable power of a 120cc gas engine, and potentially greater. Of course, managing the fulcrum location can also change the magnitude of the Output Force as well because it changes the distance ratio of both sides. So there is an opportunity to control the amount of Force we need while using the same Input Force.

That’s how the diameter and circumference (circ – equals distance rolled in one turn of the wheel) are calculated in the Tyre size table. These figures are useful for setting your cycle-computer and precisely calculating gears. Table of bicycle tire sizes. The table allows you to convert between ETRTO, English-, French-and German targets, and rim circumference etc. ETRTO Weatherproof glazing beads, bars, cills, and profiles designed to extend the life of your timber doors and windows and reduce your production time. Durodeen can be used for many applications and brings you many benefits including:

If the rim is not marked with its bead diameter you can read this from the tyre – it’s the one dimension they have in common. The main catalyst for the project was the fact that Falcon Hobby in China is now manufacturing 28, 29, and 30 inch light electric carbon props with the C2E designation. C2E props have always provided excellent efficiency relative to propulsive force compared to electric beechwood props and other carbon props designated for electric power. All tyres are marked with a pressure. Sometimes this is an absolute maximum that nobody should need to exceed, or sometimes only a recommended maximum that may be exceeded by heavier riders (such as tandemists). Same Propeller to the same RPM: With the same 28x12 PJN propeller to the same RPM and power at the shaft, the StinGR draws 15.7% less current.

The answer lies in the definition of the terms above, and if we look closely at the image below, we will see the specific things that changes Force without changing Energy or Work. As far as possible, then, use these columns to convert to ISO dimensions and then have nothing more to do with those old markings! One way to define it, popular in times past, was to measure the tyre’s outside diameter and its maximum width when inflated, but this can be misleading. For example, some tyres marked 28" are actually much less than 27 inches in diameter, while 26×1.5 and 26×1½ are two completely different sizes. Pre-machined – saving you labour time and cost, plus it removes the hidden cost of machine downtime. In addition to the various international tire sizes are also available ETRTO list (European Tyre and Rim Organisation). It is precisely this list and these numbers say nothing about the diameter and width of your bicycle wheel, as described previously.