Corbin seat backrest post diameter

[Deaner]

I am looking to make a backrest for my Corbin seat. I believe the inner tube on the seat is 3/4" OD. A 1/2" OD square tubing is too small and the 3/4" OD is too large. For those with a backrest is the tube a 5/8" OD? I am trying to save the trouble of heading with seat in hand to Den-Col Steel to try out square stock.

Thanks in advance,

Dean

 

PS any ideas for the backrest proper?

[Jim VonBaden]

I just measured my shaft and it is pretty small.

 

The Corbin seat post is 5/8", but really looks metric at 15mm.

 

Jim