Geometry & Position
One degree of head angle sounds like nothing. On the bike it shifts trail, wheelbase and bottom bracket, and with them the whole ride.
Photo: Frederik Rosar, UnsplashOne degree slacker.
An angle headset tilts the steering axis inside the head tube. The front wheel moves forward, the whole bike tilts with it, and only then do you measure.
Model frame size L, static without sag, numbers like current 29 inch downhill frames: 63° head angle, 475 mm reach, 632 mm stack, 447 mm chainstay, 1292 mm wheelbase, 349 mm bottom bracket, 200 mm fork with 583 mm axle to crown. The steering axis pivots around the centre of the head tube.
Offset against head angle.
Trail calms the steering, too much makes it lazy. Fork offset takes back what a slack head angle adds.
Trail = (wheel radius × cos head angle − offset) ÷ sin head angle, wheel radius 372 mm.
Parts for this topic
We are adding the parts for this right now. Until then, the basics are in the shop.
To cockpit