Craftworks 650B mountain bike with concentric shock mount conversion

Craftworks Cycles is based in South Australia, but founder Kain Galliver was in Taiwan during our tour and showed me his latest creation: A 650b conversion for his 150mm travel mountain bike.

Where many tinkerers are content to squeeze in some wheels and adjust tire size to accommodate the frame, Galliver took it to the next level to correct suspension and frame geometries as well as shock tune and travel. And he went about it in a rather interesting way.

Rather than create entirely new dropouts and frame mounts, he designed concentric mounting axles for the shock. This allows the BB height to drop 3mm, ending up where it should, and adjust the head angle. Detail pics and more below…

Craftworks 650B mountain bike with concentric shock mount conversion
The shock's lower mount is visibly offset from the outer bolts.

He also worked with Rockshox to develop internal spacers to modify the air volume. This had the combined effect of reducing travel to 130mm and tweaks the shock tune for the shorter travel. This was necessary to prevent the tire from hitting the seat tube since the stays are just 420mm long. Galliver says it’s quite supple off the top then ramps up nice and progressively.

Craftworks 650B mountain bike with concentric shock mount conversion

It’s using a proper 650B fork from Rockshox. Tires are Maxxis Ardent 27.5×2.25 up front and Crossmark 27.5×2.1 out back.

Craftworks 650B mountain bike with concentric shock mount conversion


  1. Cool concept. Black Market’s new full suspension bike the Roam has the ability to be a 26″, 27.5″, or 29″ bike all on the same frame using different dropouts and a different shock between 27.5″ and 29″ modes.

  2. Neither Cannondale nor Santa Cruz did single-pivot monoshocks like that first, so please stop trying to be clever in comparing this brand to them. If anyone they took their styling cues from Haro, who was doing curving/bent tubeset frames long before anyone else in mountain bikes.

  3. I’d like to take one for a spin, only bummed that with all that DT manipulation, cables seem to take the place of a bottle cage mount.

  4. The cable holders are integrated for the water bottle mount . The curvy down tube is purely about packaging – water bottle, fork crown and swingarm clearance.
    There were similar comments on the S1 downhill frame curved tube set when it was released 4 years ago – I can see how people jump to conclusions. However, the down tube was curved so the shock could sit flatter in the frame, increasing how progressive the wheel rate at the end of stroke.. Orange have just used the same idea in their 322 except they use a canoe to mount the shock lower..
    Just a note – this bike is not a finished product – it is a cobbled together frame from old prototypes just to test the concept.
    Interesting comment on brake jack – if that is the case all Kona’s, Cannodale’s, Transition’s, Scott’s, and frames that are not a true 4 bar linkage must have the same problem..

  5. <>

    Hey come on KLG, we’ve all read that all single pivots suffer from dramatic ‘brake jack’ in the FSR/Specialized literature – it must be true 🙂

  6. single pivot great, 650b trail bike with 140mm travel the way to go and only 2 bearing to replace instead of 8 or more, I like the curvy down tube make the frame almost custom design send me one please

What do you think?