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. Even worse, the same or very similar markings can sometimes be found on completely different sizes of tyre: 26×1½ and 26x1.5. It might be supposed that these two tyres are both notionally 26" diameter and one and a half inches in width, but 26×1½ is a whole inch bigger than 26×1.5. With rotating gears and rotating propellers, the Force we are talking about is torque (t). Since Force causes acceleration and torque causes angular acceleration, then torque is the force needed to accelerate or decelerate propellers. In 3D and aerobatic flight, there is infrequent episodes where the propeller is spinning at a constant speed, so infrequent episodes of no accelerate or decelerate, or rotational equilibrium. So we must consider that torque is the most important vector applied to the propeller to gain the desired result. With gear reduction, the difference is that the motion is rotational (angular) which means that the distance (d) can continue indefinitely around in a circle as if there is no floor in the image below, and Input distance continues to drive a shorter Output distance with greater Force. For Work and Energy to be equal on both sides, the upward Force applied on the Output side must be twice the amount on the Input side because of the difference in the distance.

Same RPM and Different Propeller: At the same RPM as the Q100 spun the 28x12, the StinGR with the 28x13 C2E draws 18.80% less current, develops an 8.4% higher pitch speed and 6.56% more power at the shaft.This thread's intent is to illustrate and explain the benefits that a StinGR gear reduction unit provides the electric RC aviation community.

On the Input side, Work is the Force I am applying times the downward distance the edge of the lever arm is moved. The StinGR 150 can develop the same power at the shaft as any 150cc 2-stroke gas engine, spinning a 30x12 C2E propeller to the threshold of tip speed efficiency at only 214A with a simple 12S battery configuration and the non-geared motor power equivalent of 11.2 kW. This is more than 13 HP at the shaft. Some rims are also now marked according to ISO with their bead diameter and internal section (width where the tyre fits); 622-17 for the size usually fitted to touring and hybrid bikes, for instance. But some manufacturers give the overall width instead. Subtract 6mm from overall width to estimate the rim section, or simply measure the distance between the flanges. Weight Comparison 1: The StinGR unit all-up with prop mounting hardware and connectors is 15.8% lighter than the Q100 all-up.Table of bicycle tire sizes. The table allows you to convert between ETRTO, English-, French-and German targets, and rim circumference etc. ETRTO 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. On the right side, and let's call that the Output, the edge of the lever is rising a specific distance that is half that of the Input side, over the same amount of time.

But if we only have a certain amount of strength and energy, and we cannot create new energy to help us, then how do these tools enhance our strength to move the object we never could without them? Another reason not to exceed the 2.2 limit on road is that a more bulbous tyre can deflect side ways with a noticeable effect on control and road holding. Conversely, fitting a tyre of less than 1.4 times the rim section will result in a harsh ride and more rolling drag than a larger tyre at the same pressure. Tubeless tyres Tubeless tyres, as the name suggests, do away with an inner tube and, in its absence, are reliant on the shape and tightness of the tyre bead to ensure the tyre doesn’t blow off the rim at high inflation pressures; in a conventional clincher tyre, the inner tube keeps the bead securely located under the rim hook.

The numbers and sizes of bicycle tires

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. 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. By understanding the concept of mechanical advantage using a simple lever, we can now see how Force extended over distance can increase.