2 thoughts on “The Genesis of SGB4 – the four speed revolution!”

  1. I’ve read your article on your Scott’s gearbox . My father Terry Lloyd has owned many Scott’s over the years and always found them under powered . So be designed a gearbox conversion to turn a standard 3 speed into a 4 and I’m sure he even did a 5 speed (I’ll check with him later) . These conversions were featured in the club magazine once which lead to requests from as far as Australia for gearbox conversions . But he would only ever sell people a copy of the drawings and never build the gearboxes for them . My Dad is 80 in a few weeks and still riding , at the minute he owns a Douglas Dragonfly , a 1956 Moto Guzzi 250Airone sport , a Panthar , 2 Ariels and is in the process of restoring a Piatti scooter .

    1. Hi Peter,
      It’s my father, Roger, who built the Scott 4 speed box. I think he would say that it the single most ambitious development of his racer as not only did he have to isolate the design flaws in the original but then have drawings made, patterns, castings and gears and shafts cut hardened and ground, as well as the cams, detents etc. It was all to be within the rules of the racing club where you couldn’t use components actually made by a factory later.
      I seem to remember that fellow Scott racer Derek Whittle converted his box to a four speed using Velocette components, fitting a spacer behind the cover plate to allow for the extra length. I think the gear centres are different too.
      It takes a lot of ingenuity (and perseverance!)to approach such a conversion like this I think.
      It’s great that your Dad is still riding and working on his bikes. The great thing about a passion like this is that there’s always something else you need to do… they’re never finished.
      By the way, my father’s had his Douglas 90+ for fifty years and I think it must be his favourite road bike. He use to have a Dragonfly when he was young and it was fitted with an Avon streamliner and wal philips ‘fuel injectors’. At some points he sold this and obviously having a thing for flat twins, later bought a BMW R69s when they first came out. For some reason he decided to go to a local meeting of the BMW owners club. It was the first and last time, as he was ostracised when he told them that his old Dragonfly had handled a damn site better!

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