Originally Posted by madmaxmutt
And, I think your statement flies in the face of physics (as poorly as I remember that class). You are changing the height of the fulcrum and the angle of the lever by tipping the weight, slightly (less significantly but)similar to a wheelbarrow. Not to mention that the fulcrum in this case is squishy. . .
Actually, this is a question of the engineering "statics" involved with each WDH design. I provided a very lengthy mathematical comparison on another thread, of the Andersen vs any other WDH. I won't go into that level of detail.
But the essential reason why the Andersen seems to hit a limit is because of the direction the load is being applied, it order to lift the coupler.
With any other WDH, the load is applied upward
. The ends of the bars are lifted straight up, and supported by chains, L-brackets, or some other support. The load involved in supporting the bar is vertical. Therefore, there is no practical limit to the amount of weight transfer. Indeed, we have all heard of people transferring too much weight, and losing rear wheel traction when the rear wheels drop into a low-spot.
Conversely, the Andersen works by applying the load rearward
. The chains start on a downward angle, from the A-frame, down somewhere below the ball. Pull straight back, and the large forces involved are enough to create an upward component
, which lifts the coupler (also lifting the front end of the chains!). But if you remember your basic trigonometry, as the angle between the A-frame and the chain gets smaller, the upward component of lift force becomes less. Eventually, the chain is nearly parallel with the A-frame (zero angle). At that point, pull all you want, but the coupler will not rise anymore, and you will not transfer any more weight.
You can then put in some suspension mods, but you will not transfer any more weight. All you will have done is jacked up the body from under the rear axle "fulcrum". Applying an upward load at the fulcrum does NOT transfer anymore weight. The load must be applied behind the fulcrum to transfer weight forward of the fulcrum.