Do this now: Grease your seatpost
Hey Lee,
I think that I may have a serious problem with my bike. The thing is my seat post seams to be stuck inside the seat tube. I maniaged to pull it free but it took two of my buddies to free it. One holding down the bike and two twisting and pulling up on the saddle.
When it came out there was a lot of white powdery substance on and inside the seat post and down inside the seat tube. I suspect that it is a form of corrsion forming from the 2 dissimilar metals. My seat post is 7075 and my from is made form Kinesium Alum. What can I do about this?
Thanks alot, Chris
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Hey Chris,
Yep, two dissimilar metals + water + grime + air = corrosion.
My buddy Clay had this happen recently, and he had to cut his seatpost out of his frame with a couple hacksaw blades attached to a rod. It was painstaking work, but he removed the post without damaging his frame.
The cure
Right now — everyone — remove your metal seatpost. Wipe it clean. Smear a thin layer of grease on the inserted part. Re-install. Check this once in a while.
Do not grease carbon seatposts. They don’t rust, and a little extra friction allows lower clamping torque.
Grease. Your. Seatpost!
Lee,
Thanks alot for the advidse. Who would of thought to put greese on the stinkin seat post. 2 more questions for ya about that. 1, how can I clean the crap out of the seat tube? 2, what kind of greese should I use? I have some aircraft bearing greese that i use for packing my bearings, can I use that?
I try to remove the seatpost after every wet ride and every now and again in the summer, so there’s less chance of the post and frame bonding.. it seems to work.
I’ve found that CNC’d posts tend to get stuck more than an extruded post.
Chris, any grease will do.
Cleaning … maybe some WD-40 or other mellow solvent? Oh, and a long brush to get in there. Idea: Modify a toilet brush?
About the grease – don’t use moly grease. Moly is for high load and small movement bearings. Gradually it bonds with the metal surface. This permanently reduces friction. In your seatpost you *need* friction else it will slide up and down when you least want it to. The grease if there to prevent corrosion. So – just use ordinary grease – don’t use Moly.
hey thanks lee ill have to try that toilet brush thing
Hi lee. Thanks for the reminder. some people may experience phantom creaking from their frame. this is one of the culprits. I had a creaking rocky mountain switch that used to drive me crazy tracing the source. took apart the pivots and everything. turned out to be the seatpost. After some grease the creak was gone.
Note: Take the time to get a new, clean toliet brush. 🙂
Another Note: Use the large bore cleaning tool in a gun cleaning kit. Attached a large piece of cotton cloth drenched in WD-40 to clean the seat tube. After the WD-40 wipe, attached a dry piece of cotton to the bore cleaner and run that through the seat tube a few times.
Oh, and if your bike has been out in the rain (be it on top of the car or ridden in the rain), take your seatpost off and flip the bike over to allow water to drain out of the seat tube (if it’s a continuous seat tube). I had a bottom bracket work itself free, due to water that got trapped down the seat tube. After some weird knocking noises in the crank, I pulled the BB and water came pouring out, water+BB=the bad.
as for water in your bb, drill a small hole in the shell and so the water can drain out that way!
and u can grease carbon post with a specialcarbon grease (tacx make some http://www.tacx.com/producten.php?fl=true&language=EN&lvlMain=18&lvlSub=66&lvlSubSub=222&ttop=Carbon%20assembly%20compound) and does work, put it on many a carbon seatpost!
Hey guys, thanks for all the great info.
Removing the seatpost is a good idea. Riding in the winter, in the rain, washing your bike. Getting air in there to help it dry out occasionally, is a good idea. Additionally, locking your seatpost and expensive seat in your car during transport makes sense as well.