[quote=rauce][quote=buffoon]I want to get a 28.6 seat tube instead of using the 31.7 with a shim. How short can I cut this?
LIFE OVER SIZED ROAD SEAT TUBE
Dia x Wall W1/W2/W3xL = 28.6mm x 0.75/0.4/0.6mm x 560mm
Butts: B1/B2 = 130/160
What’s the minimum you would leave for the top and BB butt?
Google tells me ~80 or so for the bottom. The top will be reinforced with a sleeve but what is needed to provide proper seatpost support?[/quote]
I would use a single butt seat tube 8/6 or 9/6. more noob friendly with with 0.8 or 0.9 at the bb and you can cut as much off the 0.6 end as you want (make sure you put it on right way around).
I’ve never messed with weenie triple butted seat tubes.[/quote]
This, plus the reason it’s thin wall is that Life tubing is their high strength alloy (same idea as OX Plat and 853). It will be harder to miter, harder to ream, and being thinner harder to control your heat. For a first bike it’s not worth the frustration.
An externally butted seat tube would saves you from doing the seat tube sleeve, if you really want to simplify things.