UK Biker Restrictions

 Over previous decades there have been many restrictions imposed upon motorcyclists in various forms. Some these being :- the compulsory wearing of safety helmets, exhaust noise emissions, the wearing of dark visors, the restriction in engine capacity for learners, the 125bhp limit, the age restriction for unlimited bhp machines (direct access test), the gas emissions from exhausts, the single dipped beam headlight when two lights are fitted (what’s that all about ?) & more recently top speed limiters.
 Some of these restrictions have been Government imposed & others as a gentleman’s agreement between manufacturers (usually to prevent Governments introducing stricter limits).
 Initially I’ll talk about engine output restrictions & ways of overcoming these (although these mods may make your machine illegal for use on British roads.
 In the late eighties & early nineties the major motorcycle manufacturers self imposed a 125bhp limit on their machines for the UK (other European countries got more severe limits). These limits were achieved in a number of different ways by the manufacturers. Suzuki, for example, welded restriction discs (like washers) into the exhaust down pipes of early GSXR1100’s, Yamaha had moulded in webs in their 1000cc FZR’s inlet rubbers & Kawasaki had carburettor caps on their ZZR1100’s that prevented the slides opening fully. All of these methods being relatively easy to rectify.

Then Triumph came along with their 147bhp Datona 1200 & the rest followed suit.
 During this time bikes were being restricted in their mid range (usually between 4000 & 5000 rpm) to meet emission levels. This was usually achieved by clever profiling of the carburettor  needles & as such aftermarket manufacturers produced kits with re-profiled needles to give us back our mid-range power. In early 893cc Fireblades in particular the improvement in the mid-range was extremely noticeable.
  As bikes became more powerful manufacturers began to restrict the power a little in the lower gears
to make them easier to ride & later on with fuel-injected bikes appearing, all sorts of restrictions to midrange power & power in certain gears was achievable. Also, for the very fast machines top speed limiters were introduced. Most of these restrictions can be removed by means of clever little electrical gadgets, these being readily available from after market suppliers & tuning shops.  
 At least one manufacturer now, as I understand it, has a two position switch to give different power options on one of their bikes. One of these positions being full power & the other for less power but giving the benefit of a softer power delivery combined with improved fuel consumption (for when you just want to ride normally). At last the rider has a choice – now that’s more like it !


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