The Sports Sunbeam was a further development , mainly in that it was fitted with the “Machined from Solid” Cross Flow Cylinder Head . This was designed round two sets of valve gear from a Kawasaki KL250 Trail Bike ( see “Cross Flow Head” ) .This gives considerably more power which makes better use of the Dneiper rear drive and 2LS front brake . There is also the full flow oil filter /cooler system and 12 volt alternator .
In order to give a more Sporting appearance the narrower BSA front forks were used with a 7 inch headlight and separate mounting for the speedometer , narrow S/S mudguards and alloy wheel rims completed the picture .
The forks incorporated two way damping and the gearchange was moved to the lefthand side . Here again the large coil can be seen under the seat and also the filler cap breather .
It incorporated all the bright ideas that I have found to work in improving a Sunbeam . It was an excellent motorcycle to ride as it went well , stopped well , handled well , and fortuitously the gearchange worked much better than any other Beam that I have ever ridden .
The engine gearbox and running gear are now being built into the S/12 project
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