3 different bikes at 3 different head angles for road and uphill , cross country and downhill
please download this set of images here: variable head angle flyer
heres the arrangement: a headtube which can slide in a circular motion and supported and positioned by a lead screw running in thrust bearings.
quicker uphill – faster downhill
it allows the rider to alter the geometry on the move.
by having a rotational headstock with its centre of rotation in front of the bike and directly over the front axle, the effect is 3 fold
as you decrease (slacken) the head angle these are the effects:
1 – you extend the wheelbase – this gives increased stability downhill
2 – you extend the fork in relation to the frame – maintaining the same frame height and the same attitude to the ground.
3 – you shift centre of gravity rearwards
DOWNHILL RIDING 55-60 degrees
a slack angle 55-60 is best for downhill: a longer wheelbase gives more stability as it keeps your centre of gravity more rearward
with the weight shift rearwards and the bikes height remaining roughly the same it prevents you feeling you are about to go over the bars.
FLAT TRAILS 60-65 degrees
general riding relatively flat tracks, enduro and jumping, is best done with around 60-65 degree head angle:
CLIMBING – 65-70 degrees
the natural inclination when climbing is to get out of the saddle but this loses efficiency if you do : for climbing use a steeper angle 65-70 degrees and you wont need to.
it gives you a shorter wheelbase and makes you go uphill faster – and around 2 gears easier. A shorter wheelbase transfers centre of gravity forward saving having to get out of the saddle.
framebuilders who wish to use this design simply contact pjcharnaud@gmail.com or submit the form below
adjustable geometry mountain bike 