Oneder

At least 350, maybe a bit more.

Vintage Schwinn

CM has a very good idea with the solid roundbar stock as "fill material" to make a super-strong, reinforced, non-hollow, seatpost. Maybe use regular JB WELD and get something like a unbent coat hanger to spread enough JB WELD (or EPOXY) within the inner area of the hollow Schwinn seat post, before ramming the sized to fit Solid Roundbar Stock into the hollow area as "fill material"......................As CM suggests, there ain't no way such a seatpost would ever break. Yeah, you would be making the bike heavier, because this would at least double the weight of the seatpost................who cares as this is not a lightweight race bike that would be used in the Tour de France or to complete the 56 miles bicycle portion of the IRONMAN 70.3 competition.

https://thecabe.com/forum/threads/ne...cturer.166556/

https://bikehistory.org/bikes/american/

https://thecabe.com/forum/threads/19...-value.137733/

https://restoringvintagebicycles.com...winn-american/

https://waterfordbikes.com/SchwinnCa...inn_1961_1970/

https://waterfordbikes.com/SchwinnCa...960/index.html

https://thecabe.com/forum/

https://waterfordbikes.com/SchwinnCa...inn_1971_1980/