Can someone explain "active" suspension to me?

synchronicity

I've been back into MTBing for a year after having been introduced to it in the mid-90s and not liking it as much as I do now (with a full-suspension bike).

Anyway, I thought monopivots were among the most active suspension. Meaning, the shock is active under all conditions... standing/sitting...

Now after reading a bit, I hear all sorts of things, for example, that four-bar link suspension is more active over all terrain. I'm confused because I thought some suspension designs were invented to reduce pedal bob & brake effects and what not, and now they're being called active.

What exactly does active, reactive, passive, and all that actually mean?
Doesn't this also depend on the type of shock used?

SDK2007

Some info here : http://en.wikipedia.org/wiki/Bicycle_su ... suspension

ride_whenever

also welcome to marketing hype 101...

supersonic

Some types are more 'active' than others. I could explain it all, but I'd just read here:

http://www.rdrop.com/~/twest/mtb/index.html

It is technical, but explains how different systems work well. An example is the pivot point on a single pivot bike. A high forward pivot will exhibit a lot of chain growth during the suspension compressing over bumps. This pulls the cranks backwards, more so in certain gears. If you are strong enough to resist this, the suspension will compress less, and will be less active. But as the article shows, there are many ideals and trade offs.