[fastxl]

Purchased a Top Fuel 9.9 and rode it 3x and cracked the seat tube. Trek replaced under warranty. I am using a 400mm seat post and the seat post extends to the top of the White Tape shown in the pic and it is inserted to between the 60-70 mark on the post. Is this post long enough? Not sure why the first one cracked and I'd rather not crack another if possible. Doesn't seem like a lot of options out there for a longer post.

Frame is an 18.5 and I am only 5'8".

Crack

 

[pinkpowa]

https://forums.mtbr.com/trek/top-fuel-sizing-thoughts-tl;dr-size-up-1061392.html

I've seen this happen several times, even when the seatpost is inserted past the top tube junction. I think it's a layup issue, hopefully corrected with the new Top Fuel/Supercaliber.

 

[driver bob]

You've got to love Trek warranty and them standing behind it. Only post I've seen longer is the 410mm Thomson but it's aluminum.