Hey,
I’m hoping someone can provide some insight for me. I’ve googled the heck outta it, and tried many options.
My cross/gravel bike (carbon) has a Thompson Elite post (aluminum) and it’s stuck. Real stuck.
We’ve tried the vice, using the frame, etc and it did t move.
I’m wondering if there’s any other options people recommend. I’m at the point I’m considering cutting the seat off the trying to cut the post from within down the seat tube (if that makes sense)
I like this frame. It’s been good to me for years and seen some things lol
Aluminum has pretty good thermal expansion so maybe a few rounds of heating/cooling might break up the corrosion in your seat tube. Cooling the post as much as possible (with ice or maybe even dry ice) after might shrink it that little bit so you can twist it free.
One thing that worked for me before was spraying with some penetrating oil ( there are a few brands) and letting it sit overnight. You can get it from Home Depot etc.
Might loosen it up but given it is a carbon frame I’m not sure the impact to the resin so googling might be required.
Even with the spray i needed to hang the seat post via a chain from the rafters in my garage and used my entire body weight plus some jiggling and after some scary noises it came out. This was with a tank of a titanium frame so I wasn’t scared of cracking it but you would likely need to be careful where you can apply weight on your carbon one.
There’s a product that I’ve had some luck with, called CRC Freeze-off, you’d likely have to go to Ackalnds-Grainger, Fastenal, or another industrial supply place to get it. Basically it’s a penetrating lube and a liquid that freezes the part so it contracts. I’d do a few sprays over a week or and then I’d give it a whack with a hammer to see if it’ll move. I’d be be leery of clamping and twisting with a carbon frame, even though they’re really strong. Make sure you completely undo the saddle clamp before you start, tape it out of the way so the oil can penetrate easier.
Another option to talk to some small machine shops and see if they’re willing to take on small jobs, they can bore or ream out the seatpost pretty quickly.
I’ve saved a few frames, but almost all steel ones… but with really stuck seatposts often times twisting on them will loosen the top part with the saddle clamp, and clamping the post itself often just crushes the post. It’s pretty easy to get to the point where you’ll have to cut the post and then look at getting it reamed out anyway if you really want to save the frame.
