Grant Erwin wrote: (clip)Anyone "been there, done that" or have any good
ideas or input?
^^^^^^^^^^^^^^^
For minimum weight and maximum strength, he should check out titanium
seatposts. Very costly, but I believe there is no better. Does his bicycle
fit him? For a road bike, the top tube should be an inch or so below his
crotch as he stands flat-footed over the bike. If the frame is too small
for him, and he is compensating by raising the seat, that's asking for
trouble.

Two other "kluge" (sp?) fixes may be possible. One would be a sleeve that
slides over his existing post, to increase stiffness. Unfortunately, if the
post is bending just above the frame clamp (very likely,) a sleeve may not
do much good. The other possibility would be an insert to go into the post,
increasing the stiffness. Possibly a close-fitting insert at the bottom,
supplemented by a sleeve over the outside, would solve the problem.

If his bicycle frame is too small, and he doesn't want to buy another bike,
possibly a tube could be welded above the clamp, part-way up the seat post,
to add stiffness. Welding bicycle frames can be very touchy, however, and
should be done by someone who understands it.

This might look a little wierd, but would he consider a diagonal brace from
the top tube to a point somewhere below the seat (clamped at both ends--not
welded)?