Originally Posted by bellweatherman

This really depends. I too have heard the 1.5" general rule of thumb. Don't know where that came from, but it's got to be made up. If you are running a superlight fork, then I'd be wary to have a lot of steerer exposed. However, for the really tall guys on smallish frames, you don't really have much of a choice. I know a guy, pro basketball player, who had to have a ton of spacers. He couldn't get a frame his size without going custom, so he just went with the largest size the bike shop had and stacked a ton of spacers on there.