Hi Guys,

I'm getting a 350mm seatpost for about 25 dollars less than a 300mm, so question is, if I dont need that long a post, can I just cut it?

Its a CF post, so is it safe to cut it? How do I cut it?

Yes. The manufacturers have a minimum length that they require to be in the seat tube. As long as you're within that range, you'll be fine.

Use a hacksaw.

To cut it you will need a fine tooth hacksaw blade and a cutting guide to keep the cut straight. You can certainly cut it but make sure that you leave plenty of post in the frame. It needs to go an inch or two below the bottom of the top tube to make sure that you don't break your frame.

Easton used to have a guide for cutting carbon posts on its website.

One thing you also should do is to wrap the post in masking tape to keep the carbon from splintering. Just cut through the masking tape.

And to reiterate what others have said, be sure to maintain the minimum insertion depth. If the post requires 5 cm be inserted, then you need to insert 5 cm even after you cut it.

My Thomson post has been jagged for years after a very crappy cut. It hasn't hurt anyone.

Just cut it and leave enough.

Or use this. Park has a cheaper version.

Realize that carbon steerers on forks are routinely cut to fit. Cutting a seatpost is really nothing different.

As others have said, make sure you leave the minimum insertion distance ( and little extra for error or future adjustment)

And use a sharp, fine tooth hacksaw blade for a nice clean cut.

Thanks guys.

I think I read somewhere to put blue painters tape where you are going to cut it to avoid scratching the post and it would give you a cleaner cut.

i had my aluminium seatpost cut. I think you can do it to carbon just like with a fork. the fork needs to be cuts squarely because it needs a flat end for headset loading but for a seatpost it doesn't matter so i think you can just do it yourself without a saw guide. do wrap the place you cut with tape first and cut throught the tape. it stops the carbon from splintering. similarly, cut a a nick on one side first and then cut from the opposite side. this will prevent the final cut tearing the fibre at the end.

also be sure to wear a mask or something - the fibers are not so great on the lungs. but now that i think about, you could probably use water to make it a wet cut - this would cut out the dust (same idea as wetsanding).