When we tested bikes for heavy front loads, we found that the flex of a quill stem did cause some trouble. There was a slight lag of the fork after the steering input. This was with 30 lbs. on a porteur rack... In normal riding, even with fully loaded front low-rider panniers (which are much closer to the steering axis than a porteur rack), I haven't felt this, and I doubt it would be an issue even for a strong rider. The front fork and wheel of most bikes has too little inertia to make itself felt that way.
The flex of the stem does not appear to be the problem - my Grand Bois Urban Bike is equipped with a very flexible Alex Singer stem. The stem flexes so much that my hands touch the load as I torque (slightly) on the handlebars. However, because the stem clamps directly to the steerer tube, the handling is lag-free even with a heavy front load. It's the quill in the steerer that appears to be the cause of the flex that causes the lag in the steering. (We had four testers ride the bikes without sharing their experiences until after the testing was over, and all commented on this, so it's not a placebo effect.) However, I'd like to stress that this is an issue only with heavy front loads. For a porteur bike, I feel that a clamp-on stem is preferable to a traditional quill stem. Otherwise, I don't see much advantages one way or the other. Jan Heine Editor Bicycle Quarterly http://www.bikequarterly.com Follow our blog at http://janheine.wordpress.com/ -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
