[1strongone1]

I was wondering if anyone knew how much seatpost one should have inserted into the frame? It is a ti seatpost and a ti frame. I currently have 4.5" and was wondering if I could trim it down a little without worrying about frame/post damage.

Thanks for the help.

 

[29erchico]

Most mfr. state 4" min. IMO that 1/2" more you have is perfect.

 

[Quasi]

was wondering if I could trim it down a little without worrying about frame/post damage.

Is it getting in your way? Make sure you use Ti antiseize.

 

[langen]

i have broken an alu frame because the post didn´t overlap enough. the post should at least be level with the lower edge of the top-tube. or else:

 

[DMFT]

I believe the general rule of thumb is : As long as it passes all the way through the TT, you'll be Ok. It doesn't have to pass by a lot, 1/2" - 1" should be fine.

 

[1strongone1]

Thanks for all the replies, I will measure accordingly.

 

[MDEnvEngr]

Stick your finger down into your seat tube. On most Ti frames, the top couple of inches of the seat tube is a machined piece made to fit the seat post. It's a smaller ID to do this correctly. If you have one of these, that is the only contact between the post and your frame. Any seatpost below this insert does not contact the frame and therefore may be cut off.

B

 

[Endomaniac]

Agreed with MDEnvEngr, your Blacksheep has an aluminum seat tube shim in it. Any post that extends beyond that shim is useless as that it isn’t contacting anything. As well a TI post that stops in the middle of the shim can wear a spot in the shim if the post flexes allot (happened to me before). Optimal scenario is the post is about the same length as the shim. But really, a half of inch at the bottom of a TI post weighs what? Maybe as much as 4 sideknobs on a tire? So if you trimmed 1 side knob of each side of each tire you could save the same but in rotating……you see where I’m going. What if you want to use that same post on another frame one day and it a half an inch too short? I don’t know what Erikson charges for one of those posts but I suspect they aint cheep. Of course if you’re an elite racer or narcissistic bike part color changer please disregard my sensible argument.

 

[1strongone1]

Agreed with MDEnvEngr, your Blacksheep has an aluminum seat tube shim in it. Any post that extends beyond that shim is useless as that it isn't contacting anything. As well a TI post that stops in the middle of the shim can wear a spot in the shim if the post flexes allot (happened to me before). Optimal scenario is the post is about the same length as the shim. But really, a half of inch at the bottom of a TI post weighs what? Maybe as much as 4 sideknobs on a tire? So if you trimmed 1 side knob of each side of each tire you could save the same but in rotating……you see where I'm going. What if you want to use that same post on another frame one day and it a half an inch too short? I don't know what Erikson charges for one of those posts but I suspect they aint cheep. Of course if you're an elite racer or narcissistic bike part color changer please disregard my sensible argument.

Thanks for the help, I will check it out.