Front/rear wheel attack position weight distribution – auto racing wants 50/50. What’s the theory on two-wheeled sports where body weight has such a huge impact? Is it 60/40 on flat ground? How does your RAAD affect that, if at all? We want to be able to set up suspension along with rider position. Does the front/rear weight balance shift with RAAD from xc race to dh? How? Is one more important than the other?
I hope this doesn’t drive you nuts. I’m hoping you tell me they are just two different things.
Thanks again. You’ve made me very busy thinking, talking to customers and measuring shit… Nice work.
Thanks for buying the Dialed book, and for using the methods at your shop. More and more bike professionals are starting to use the Dialed approach. It’s simple and makes sense.
As a refresher: RAD is the distance between your bottom bracket and grips. This is determined by your body size and proportions. RAAD is the angle of your RAD compared with level. In general, XC bikes have low RAADs, and DH bikes have higher RAADs.
My theory on bike weight distribution is this:
We should put all of our weight into our feet, which puts your weight in the bottom bracket and distributes it to the tires based on the ratio between your bike’s front center and chain stays. That used to be about 45/55 front/rear. These days it’s more like 40/60 with some enduro bikes putting even more weight on the back of the bike.
That said, we should occasionally put power into the handlebars and front of the bike. This makes angle changes in bumps, and it helps drive the front tire into the ground for cornering. There’s an important distinction between weight and power. Handlebars should get no weight, but lots of power.
By the way: Bikes with a major rearward weight bias can inspire confidence while plowing through gnar, but they require more effort in flat corners. While the new geometry is fashionable, for many riders it’s not helpful. Smart people tell me the geometry pendulum will swing back to more moderate numbers.
To answer your question: Cockpit setup should have nothing to do with weight distribution. The rider should balance on her feet. The bike’s weight distribution is based on the position of the bottom bracket within the wheelbase.
I hope this helps!