The Ariel Arrow 250cc two stroke twin of the early sixties was new and a very different attempt at motorcycle design, with a mixture of clever ideas (which should have been developed more) and some not so clever ideas as well. It couldn't be classed as just a prototype of course, it did sell very well for a few years.
http://sump-publishing.co.uk/ariel%20arrow.htm
This is how I saw it at the time:-
Its excellent handling with its trailing link forks and very stiff pressed steel frame, unfortunately was compromised by it's (too small) wheels and I was forever dragging everything on the road if I leaned hard into a corner! - poor brakes, smokey two stroke iron barrelled engine (which itself actually had some good innovative features to assist with maintenance).
However, any of these innovations were badly compromised by one or two cheapskate ideas which cancelled out any of the benefits the new design might have brought to us!
The "cheapskate" solutions used in it which bothered me most were:-
At first glance a good idea and the way it was arranged was fine - the two (seperate) cranks were joined in the middle (but with a keyed taper arrangement held together by an Allen head bolt. This bolt was accessed through the right hand (hollow) crankshaft by an Allen key).
However, even though it was keyed, it tended to move a little, compromising the ignnition timing - probably splines or Hirth Couplings could have been used instead.
Each crank could be extracted by removing the crankcase sides containing the main bearings) - the main crankcase and gearbox was all one piece.
The big end bearings were of the crowded roller type (no cages).
Single carb, ( to me, a two carb setup would have been a better idea).
The pathetic two transfer ports were incredibly small by today's standards.
The plain bearing used in the gearbox (made of sintered iron), was prone to break up and of course the traditional type Burman (I think) four speed gear cluster itself was already outdated, especially when used in conjunction with a two stroke twin, - not a great marriage! The equally old fashioned chain primary drive was not really the way to go at that time either! but the fact that a forward thinking design was still being manufactured with these old traditional ideas still incorporated (because of management restrictions no doubt!) was a bad idea, especially in the days of the upcoming Japanese invasion! - sad but true!
Still loved it though!
(the bigger wheels helped considerably!).
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Originally Posted by ken seeber
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