Originally Posted by
speshelite
I have to warn everyone though: none of these rear sus designs are damped, so they will bounce noticeably on rebound. The bobbing also robs you of power. There's no free lunch here and you'll pay the price one way or the other. Not to mention the seat rocks back and forth and does not remain level.
This is not true of all of them. There have been a number of in depth reviews of some of the newer offerings, and some of them seem to work very well without the issues you are describing.