Originally Posted by
bizzz111
... How much flex are we talking about? Is the bottom bracket going to be dragging on the ground and spraying sparks if I throw and adult on the back?
I have an old steel giant iguana that I could strip down and build up for about the same price as a safari, but it would just be a huge PITA to make it compatible for disc brakes etc.
My Xtracycle is now on a no-name aluminum MTB frame that I salvaged out of a dumpster a few years ago. I'll try to take a better photo this weekend. I've ridden it maybe 30 miles now, under loads varying from ca. 40 lbs up to maybe 120 lbs. I have ridden my wife around on it a bit, less than a mile.
Anyway, flex IS noticeable if you look for it; if you do a quick slalom with the handlebar, you can feel the thing getting wobbly. But if you hold steady, the bike feels fine. But I'm talking about side-to-side flex here. I have not detected any vertical flex, and I wouldn't expect to. Virtually all of the extra weight is on the back wheel; there is hardly any additional weight in the center of the bike. So I'm not worried about the frame. I'm much more concerned with the back wheel, which is why I built up a new one with 48 spokes.
Mine has early 1990's era Shimano cantilever brakes on it. They work okay, but I'll probably upgrade to V-brakes when Nashbar has good deal on them. Since the Freeradical is set up for them, that seems the way to go.