Mountain bike geometry has evolved a fair bit in recent years. On the whole, trail bikes of today are considerably longer in the wheelbase and slacker at the head angle than they were just a few years back. Certain companies are pushing the boundaries more than others in this respect but slowly and surely we’re all starting to reap the benefits of this pursuit to create better handling bikes.
To find the limits first you must reach them(!) and that’s why Jon Woodhouse, Editor of What Mountain Bike magazine, took it upon himself to experiment outside of the boundaries depicted by the geometry sheets of current manufacturers. Jon commissioned frame builder BTR fabrications, based in Somerset, UK, to produce a one-off hardtail with geometry you simply cannot get anywhere else.
Jon combined all the current trends of geometry to produce a bike with a 63.5-degree head angle and a 656mm top tube length – that’s the size of a large forward geometry Mondraker frame. To counter those radical dimensions, the BTR’s seat tube angle is set at an equally extreme 75.5 degrees. The chainstays of the frame are long enough to squeeze in the 650b rear wheels with enough clearance for mud but that’s it, in fact the back end was set as short as it’s practical to do so. Similarly, the bottom bracket of the frame is slammed way below the axles.The BTR was then fitted with Mondraker own brand On-Off’s 10mm stem, allowing for steering geometry that can’t be achieved with conventional parts. The wheelbase is, well… just look at it!
Watch the video below as Jon puts his bizarre looking creation to the test and reports his findings.
Video: The extreme geometry hardtail