Hi, been lurking for a while and have valued the information I've read, and hope to contribute in the future. But at the moment I have a question:
I recently aquired an older time trial bike from a friend. It is of unknown origin, but is of quality steel (SLX or 531) and is fillet brazed (or extremely well-finished tig). Due to its compact design the seat tube extends about 4 cm beyond the top tube. I want to use an old aero seatpost (shimano 600), but when used it would be buried up to the aero part, with the actual inserted shaft being about 4 cm, so maybe just a tad inside the joint.
The person I bought it from thinks this would be fine because it is of quality steel. Part of me agrees with this, and also thinks if brazed it would be a bit stronger at the junction. However, most of me thinks I'd be flirting with breaking off the extension, not to mention hurting myself pretty good. My weight is usually between 150-160 lbs, and i do push the saddle all the way back on this bike. I should mention that there's a fine seatpost on the bike already (suntour superbe pro) and therefore have no great need to put the shimano post in. I also should mention that I'd like to drill the seatpost a bit, for bikedork's sake.