Litech / Lodestar magnesium frame geometry question

[EuroMack]

I am about to buy a Litech magnesium frame from ebay, but I am not sure which size to buy becasue it is not clear to me how the sellers measured the top tube.

Can someone with a 17in or 19in frame measure actual top tube length, from center of head tube to center of seat tube?

Also, would you measure 'virtual' top tube length by holding the measuring tape horizontally from center of head tube to center of seatpost?

If you do not have a frame to measure, but have experience with Litech and would like to help me with sizing, here are the relevant details:
I currently ride a 19in Specialized Stumpjumper M2 with 320mm seatpost and 105mm stem. I have a 34in inseam.

[Rufudufus]

According to the add when I bought my 19-inch on ebay, the top tube is 591mm or 23.23", center to center. I'm 5'11" with a 31-inch inseam, and run a 105mm stem. I think the 17 would be small for you.

I'll try to get you the horizontal measurement tonight.

[Ronbo1]

I'm 5'10 with a 31" inseam and my 17" frame seems like it will be fine. I like mine a "little" small.

[BadHabit]

I am about to buy a Litech magnesium frame from ebay, but I am not sure which size to buy becasue it is not clear to me how the sellers measured the top tube.

Can someone with a 17in or 19in frame measure actual top tube length, from center of head tube to center of seat tube?

Also, would you measure 'virtual' top tube length by holding the measuring tape horizontally from center of head tube to center of seatpost?

If you do not have a frame to measure, but have experience with Litech and would like to help me with sizing, here are the relevant details:
I currently ride a 19in Specialized Stumpjumper M2 with 320mm seatpost and 105mm stem. I have a 34in inseam.

17" is too small. I have a 31" inseam and a 17" Lodestar with quite a lot of post showing. I have frames in both sizes, actually. Let us know if you still want a precise measure.