Kingcycle TT project

Kingcycle TT project

There is a bit of history to this one…. I first worked with Miles Kingsbury of Kingcycle back in 1998 when he helped me with my masters thesis looking at elliptical pedal motion. Having had a long held interest in human powered vehicles, I asked if he might have a bike I could try out to race on, and was duly lent a Kingcycle Wasp. I had a lot of fun racing that bike, including winning the road race at the HPV world championships in Belgium in 2000. Miles and John (his father) have a long, successful history of HPV design, building and racing – you can see a brief history here – including holding the world hour record for many years. In 2002 I worked with Miles on a new record-attempt bike, the Mango – details here – which I rode to a British 200m record of 67mph, and then to an infamous crash at 70mph the next day…..

Which brings us to the connection with this project – for the Mango drivetrain, Miles came up with a clever shifting mechanism where the chain remains still and the cassette slides underneath it. We talked at the time about how this would be neat for a time trial bike, as once in top gear the rest of the cogs would be hidden inside the disc wheel. So when Miles’ son David asked me to build him a TT frame, the idea got resurrected and we started on an English Cycles/Kingcycle collaboration.

This is the result – at least my part of it, Miles will be adding the custom narrow crank/BB assembly and the custom rear disc wheel with shifting and drum brake. David decided to use the fork and stem from a Giant Trinity, so there is an oversize headtube to mate up to this assembly. The frame looks very simple with essentially just two tubes, but was actually quite a challenging build. The Q-factor on the cranks is only 70mm, so there isn’t room for conventional chainstays. But with the elevated stays it allows for the chain to run directly next to the disc wheel, keeping everything very narrow. USE R1 bars at the front, painted to match.

Just frame photos for now – the white/blue one is David’s, the identical red one is for Miles. I will post updates once the bikes are assembled.



  1. looking forwards to see the complete built. very interesting & cool!!

  2. Interesting concept – would this be competition legal for TT or Tri and is the team planning to make it available to the public?

    • This is legal for UK time trials and triathlons. But not for UCI events. We’ll see how it all works out….

  3. Super cool frame, I love to see designs that break the mold! As an aspiring frame builder I’m wondering, why does the bottom bracket have a clamping mechanism?

    • Hi Henry, the bottom bracket/crank assembly is a custom part – rather then threads or press fit, it slides into the shell and then is clamped in place by the two pinch bolts.

  4. Always did like the sliding cassette shifting. Have some detail pictures of it from George Leone and have been thinking on how to incorporate this into a future project ever since. Very much looking forward to seeing the finished product!

  5. You do make it look simple, Rob. The intersection of the tubes is very elegant.

  6. Can you tell me the weight of that frameset?

    • 2100g for the frame. Thanks, Rob.

  7. beautiful frames
    do you have any picture of the bikes assembled ?

    • not yet…. will post them when I do!
      thanks, Rob.

  8. I realize this hasn’t been updated in a while. Was this project ever completed?

    • I’m not sure…. I know David raced the bike successfully with a single fixed gear, but I haven’t heard if the sliding cassette made it off the drawing board…..

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