Difference between revisions of "Moped"

'''Mopeds''' are a type of low-powered [[motorcycle]] designed to provide economical and relatively safe transport with minimal licensing requirements. Mopeds were once all equipped with bicycle-like pedals (the source of the term, motor-pedal), but ''moped'' has been increasingly applied by governments to vehicles without pedals, based on their restricted [[engine displacement]], speed, and/or power output.  Mopeds occasionally resemble powered bicycles, but most are now [[step-through]] designs (of both kinds, having either large or small wheels) and step-over designs similar to a regular motorcycle.  Although mopeds usually have two wheels, in some jurisdictions low-powered three or four wheeled vehicles are also classified as mopeds.

By the 1980s, it was obvious that the pedals on mopeds were no longer performing any useful function, in fact the performance of the 49cc engines available was delivering speeds in excess of 80km/h, a common model in the UK being the [[Yamaha FS1E]].  Due to emerging safety concerns that resulted from the considerably greater speeds that newer mopeds were capable of reaching, western jurisdictions introduced new regulations (eg UK in 1977)[http://www.classicbikepictures.co.uk/c319/p2117/yamaha%C2%A0fs1e.html Yamaha FS1E Classic Bike Pictures], limiting the speed of these "mopeds" to 30mph (and abolishing the requirement for pedals).  In some cases, the power restrictions (such as perforated plates in the inlet tract) were primitive and easy to bypass, but the larger manufacturers such as those from Japan restricted engine breathing with smaller carburetors (eg 16mm replaced with 13mm) and modifications to cylinder ports and exhausts.  Then they fitted [[CDI]] ignition systems tuned to limit maximum engine revolutions; the [[Honda MT50|Honda MT/MB50]] was built to run to 10,000 rpm, but the combined restrictions cause it to run out at around 6,500 rpm. Illegal de-restriction of such models is extremely difficult, requiring replacement of piston, barrel, carburetor and CDI electrics, and possibly the crankshaft and the exhaust as well.

The wide availability of previously-used but still functional small motorcycles in western societies enables and encourages cheap forms of racing, wrongly called moped racing. Dirt-racing forms of this sport is sometimes staged in the stadiums of agricultural shows, where, unlike football and athletic grounds, the surface is not too important. One popular series uses chicanes consisting of stacked large-diameter tractor tires and requires a team of riders, each doing ten laps and then pulling into the middle of the ring for change-over. Two heats and a final, each lasting 25 minutes, can be held in one day interspersed with speedway racing and other displays. Another series once held on full-size race-tracks, including [[Le Mans]], ran for 25 hours (typically 3.00pm one day until 4.00pm the next) and was billed as "the longest race in the world".