It's all about finding the perfect fit and balance, and the best sizing of the "magic triangle". The magic triangle as I call it, is the 3 contact points on your bike - the saddle, the handlebars, and the pedals. Once you get the dimmensions of that triangle dialed in, you will own the most efficient and comfortable bike in the world.
I'm 6' 2", and I needed to put a setback post on one of my 'Hoppers. I could have put a longer stem on, but that had me too far over the front wheel, and too much weight on my hands. I also could not move my saddle back far enough with a straight post. So my option was to go with a setback post, which did the trick nicely.
Here's a pic of my 21" frame that I use for aggressive XC. The setback post gives me a bit more cockpit room as well. I also ride 23" frames for XC racing, and do not require a setback post on that frame, as the larger frame allows just that much more cockpit space.
Oh, and it's never a waste to buy Thomson.
Last edited by shane45; 11-12-05 at 05:53 AM.