Mountain Bike Reviews Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
1,085 Posts
Discussion Starter #1
I just bought a bike and it came witha thomson seatpost, unfortunately the seatpost is way too long for me and i can lower it all the way because of the water bottle mounts, i was wondering if it is ok to cut the seatpost or if cutting it would weaken it structurally, i have a professional pipe cutter but am not sure what to do with the varying thickness of the post. On a different note, if anyone else has a thomson 29.4 seatpost in a shorter length than 410 and wants to trade id be willing to discuss.
thanks
 

·
Registered
Joined
·
3,882 Posts
Cut it.

There is no difference in the wall thickness as it gets closer to the clamp. Be sure to note that the post needs 4" of insertion, so when you cut it, you will still need to keep a minimum insertion. Cut it with the pipe cutter, then file the edges clean.
 

·
otb club member
Joined
·
2,938 Posts
More important than "minimum 4" insertion" is:

The 4" minimum insertion mark is not very useful, in my opinion. Almost every frame manufacturer recommends that the post be inserted so that it extends beyond the junction of the top tube and the seat tube. This is important, as the amount of seat tube above the top tube can differ significantly between frames. You could easily be at the "minimum" mark at the top of the seat tube and the post not actually extending below the top tube. This doesn't affect the post as much as the frame. Thomson puts it this way, "On some bicycle frames the seat tube extends long above the top tube. Make sure you insert the Thomson Seatpost so that it sinks below the frame's top tube. The Thomson Seatpost is perfectly safe to run at it's max line in any frame. However, please be warned the if the seatpost is not sunk below the top tube of the frame, there is a risk of damaging the bicycle frame."

-Chris
http://www.enduroforkseals.com/
 
1 - 4 of 4 Posts
Top