Why is travelling through the Stargate from Earth such a bumpy ride?

Question

During the movie and the early seasons of Stargate SG1, travel through the Stargate from Earth is an extremely bumpy ride, often resulting in the feeling of being chilled, being thrown out of the Stargate upon arrival, etc.

It is covered in Stargate SG1 that an object in motion maintains its velocity when travelling through the gate - if this is the case then surely in order to be thrown out of the gate at your destination you'd have to take a running jump on entry at your source.

Since this doesn't seem to be the way the team enters the Stargate on earth, why is travelling through the Stargate from Earth such a bumpy ride?

Answer 1

On the Stargate Wiki article for wormhole physics, it states:

The speed at which one enters a wormhole is the same at which one exits a wormhole. However unstable energy sources can cause travelers to exit at far greater velocities then they enter (Emphaisis mine).

During season 1 episode 17: Solitudes, it is mentioned that they've installed frequency dampers to reduce the vibrations:

JACKSON: General, when we first opened our Stargate, it used to shake ... A LOT. I mean, the ground, the whole facility, everything.

HAMMOND: We've installed frequency dampers that limit that to only a slight vibration.

At various points through the series, Captain/Major/Colonel/Doctor/Samantha Carter makes changes to the way the dialing program works to stabilize how the Earth Stargate interacts with other Stargates, which greatly improves how they arrive at their destination. Thus, no more of the freezing or getting thrown out at the distant end.

The Dial Home Device (DHD) would normally do this, however since Earth doesn't have a DHD, other means had to be derived which is why it was happening in the first place.