11/11/2023 0 Comments Revo x spinning comboTo put that into context, that’s roughly the difference between riding with a dirty and clean chain, according to Jason Smith of Friction Facts. In contrast, the most efficient dynamo hub (the SONDelux in this test) will only add around 6.5 watts at 30km/h with the light switched on. This drag will increase as more power is drawn – running a 1.5-watt instead of a 3-watt headlight would yield less drag (but all else being equal, you would have less light). When this current passes through the stator, it works against the magnets in the rotor, increasing drag. In simple terms, drag increases when the light is turned on because the electricity produced by the generator, which in turn powers your lights, creates its own magnetic field. If you kick things up to 30km/h that figure rises to around 8 watts for the least efficient dynamos. With the light switched on, you can expect losses of around 6 watts at the same speed. Lab testing by Fahrrad Zukunft in 2014 showed even the least efficient dynamos only added roughly 3 watts of drag at normal riding speeds (20km/h) with the light switched off. How much drag does a dynamo light system add?Īny dynamo system will introduce drag, but the difference is likely to be imperceptible for most people riding at normal speeds. Most rear lights now use a coaxial or twin-core cable to connect to the headlight, but older lights sometimes used the frame of the bike as the ground for the circuit. The band-on Exposure Red Eye connects to the front light via coaxial cable. While a dynamo typically refers to the component generating power, it’s also often (albeit incorrectly) used to describe a light powered by a dynamo hub. Sturmey Archer’s widely-sold Dynohub, which was originally released in the 1930s, became synonymous with generator hubs and ‘dynamo’ has become everyday parlance in the cycling world (even if the name is technically incorrect). So where did the name ‘dynamo hub’ come from, and why has it stuck?Īs with a Xerox, Velcro or an Escalator, Sturmey Archer is the victim of a form of genericization. As such, it’s technically more accurate to refer to a dynamo hub as a generator hub. The key difference is that a dynamo in the strictest sense of the word produces direct current (DC). Gettyįor the pedants out there, most dynamos are technically single-phase alternators (a magneto if you want to be really specific) that produce alternating current (AC). A dynamo, be it a bottle or hub dynamo, is technically a ‘magneto’.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |