On Thursday, 27 March 2025 at 3:47:00 am UTC+11 Mackenzy Albright wrote: Seat tubes themselves are usually one of the thickest tubes, no?
Not at the seat lug end. Seat tubes are frequently only single-butted, with the thicker butt only at the bottom of the tube where it meets the bottom bracket shell. The inserted seatpost provides extra reinforcement at the top. With a normal 28.6mm OD seat tube, you can easily figure out the approximate seat tube thickness at the seat lug by subtracting the seatpost diameter from 28.6 and halving the the result. So a frame that takes a 27.2 post has a wall thickness there of ~0.7mm, with a 26.8 post it's ~0.9mm, etc. Here's a selection of seat tubes from the Columbus catalogue. All the 28.6 OD tubes they show there have a 0.6mm wall thickness at the upper end. [image: columbus.jpg] Nick Payne -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/rbw-owners-bunch/0e827113-3775-4a11-bc57-0d6b115f2eefn%40googlegroups.com.
