Weight transfer, braking and suspension.

[obsolete]

We all know that about setting the brakes before we brake hard to transfer weight forward increasing the contact patch of the tire. This came up in a conversation last night while JWM2k3 and myself were looking over Drop’s Beemer. From what I understand the BMW funky weird shit front end keeps the bike from diving under braking. I asked how that affects weight transfer and the increase of the contact patch under hard braking.

I looked at this from a drag racing aspect in that there needs to be adequate suspension movement to allow greater weight transfer under acceleration to increase rear wheel traction / contact patch. This brought up what if the question if a bike had solid forks (no movement) would you still get the same weight transfer and contact patch. I think that it would not because, equating it back to the drag racing example, a road race type suspension in a car leads to terrible launches due to the slow unloading of the front and subsequent lack of weight transfer.

What are people’s thoughts on this? Will the lack of suspension dive on the BMW affect the size of the contact patch achievable? This is not to say the bike has bad braking, Jaime said it's fucking fantastic. This is more of a discussion on the physics behind it.

[Pigman]

In Drag racing it actually is Better and a necessary mod to do to go fast…they have straps that compress and lock out the front forks so to speak. Allows more power and weight transfer directly to the rear than if left alone…Just as Factory connection has one for motor cross and dirt bikes also. They lock out the front for the hole shot and then it releases after compression is applied. Better traction all around just not safe for turns and twistie's.

[Paul_E_D]

The BMWs still dive, just not as much. More like a GP bike. Less transfer fore and aft makes a bike more predictable going into and out of the corners. You still need SOME transfer, just not as much as your typical street bike, which is a bit like a hobby horse.

[ed]

Interesting concept... I wonder if the contact patch increases more on the beemer because more of the weight transfer movement is absorbed by the front tire?

The autocrosser types talk about the rate of weight transfer, this may be involved somehow too...

Coming from the car world, it seems that there is a lot more talk of traction in general from the motorcycle peeps: paint, tar snakes, sand, weight transfer, etc etc.. Makes sense, and good stuff to know.