[raspberry]

What's the minimun seatpost needed in the frame to keep it from creaking?
It's a 400x30.9 Thompson and needs to be trimmed.

 

[DaFireMedic]

What's the minimun seatpost needed in the frame to keep it from creaking?
It's a 400x30.9 Thompson and needs to be trimmed.

I'm not sure that creaking is the problem so much as damaging the frame. One rule of thumb is to make sure that the post extends at least 1 inch below the first frame tube that connects with the seat tube.

 

[raspberry]

Thanks. That's about 4" into the seat tube for me.

It's cut and lost 66g. Glad I don't have to lug that hunk up the hill anymore!
The seat tube is oval in the inside. Cool.