John’s 650b road

John’s 650b road

A few years ago, John had me build him a superlight 700C bike for all day adventures. The bike has worked well for him, but for rougher roads he was looking for a bit more comfort, so asked me to create a similar fit and feel, but with 650Bx42C tires. This is the result – the Grand Bois Extra Léger tires are mounted on Enve carbon rims laced to Chris King R45 disc hubs. Parts are a lightweight mix of THM Clavicula cranks, SRAM Red and the new TRP Spyre mechanical disc brakes. Calfee neatly integrated an Enve bar and stem into one piece for the cockpit. For additional comfort there is a Syntace HiFlex seatpost (saddle and pedals shown here are mine). To provide a gear range suitable for steep climbs and long days, the chainrings are 34/48 with an 11-36 cassette.

The goal was to build the frame as light as possible – it ended up at 1416g. The tubing is a mixture of True Temper S3 and OX Platinum for the front triangle, with custom shaped Columbus chainstays and my usual 3/8″ wishbone seatstays – in this instance asymmetric to clear the chainstay mounted rear disc caliper. John also asked for a carbon headtube insert. All cables are routed internally through the downtube, with the front brake cable running inside the fork blade. For long days in the saddle there is an additional bottle cage mount under the downtube, and pump pegs under the toptube.

Super sparkly paint is by Eric at Colorworks, and the final weight complete as shown is 17lbs.


  1. That is AWESOME!

  2. Really, really nice… except for the unicrown fork.

    A bike this nice should really have a flat, cast fork crown. Much prettier.

    • Beauty is in the eye of the beholder! And in this case my design brief was to make the bike as light as possible, and a unicrown fork is much lighter than a lugged construction. Glad you like it otherwise,
      Cheers, Rob.

  3. looks very good this bike! 😉


  1. Bike porn - Page 1594 - London Fixed-gear and Single-speed - [...] Aethetically, I always have a bit of a love hate thing with English, but I thought this was really…

Leave a Comment