Classic & Vintage - How do you keep from putting those little zig zag marks in your seatpost?

:innocent:

you need one of the following, an adjustable reamer that fits from about 25.6 to 30.0, a flex hone the size of your seat tube, or you can go the cheap way like a true C&Ver and go get a brake flex hone.

polish or hone the inside of the seat tube

i always make sure there are no burs on the edge of the tube and push/pull the post straight.

i also am very careful when setting my seat height. error high and work down.

you need one of the following, an adjustable reamer that fits from about 25.6 to 30.0, a flex hone the size of your seat tube, or you can go the cheap way like a true C&Ver and go get a brake flex hone.

polish or hone the inside of the seat tube

Also, use a small file to first de-burr the pinch slot and the top of the tube.
You can also use sandpaper rolled around a dowl to clean up the ID of the seattube like a hone.

They're caused by burrs, as noted already, and twisting. We twist to make moving the seat up and down easier.

Resist the temptation to make it easier like a Christian monk resisting... temptation. ;-)

Cool. Once I get this seatpost out I'll be sure and clean up the tube. The seatpost isn't stuck or anything but the previous owner of my new '73 Raleigh Competition was quite a bit shorter than me. You really have to pull hard to do it straight.
I'll try to think like a monk.
Thanks guys.

Geeze. Took the post out. Sorry, the monk approach was hopeless. It looks like some guy at the factory took a hammer to this thing just before they painted it. Burrs to me are little bits that stick out. This is more like stalactites or something.
That's what I get for buying a boom bike.

Bicycle cavities need attention prior to using them. This is how I approach each cavity (http://www.mytenspeeds.com/My_TenSpeeds_1/Site%20Contents/How_To_Do_It/How_To_Do_It_FrameCavityPrep.htm)(there are three - bb, seat post, head tube).

After I make sure the seat post opening is sized correctly. I deburr the inside edge of the tubing with a half round file and then use a brake cylinder hone, using light oil for lubrication. Note, tip the seat tube downwards so any debris that's removed won't fall down into the BB. Once you've smoothed out the seat tube, clean it out touch up any bare metal on the rim of the tube and lightly oil the inside of the seat tube. You may find a better solution, but this has worked for me so far.

Mike

Cylinder hone

http://i1128.photobucket.com/albums/m483/MichaelAngelo54/Tandem/Brakehone.jpg

Not sure, but I believe OP was wondering how to avoid the scratches when you are removing the post for the first time.....and I don't think there is an answer except pure luck (which he apparently didn't have this time).....

After you've cleaned things up, if you have deburred then twisting gently shouldn't make any difference; if not regardless of how you pull you'll end up with some scratches.

Mark

http://www.bikeforums.net/showthread.php/528077-Galled-seatpost-Cleaning-up-a-seattube-501?highlight=seatpost

Not sure, but I believe OP was wondering how to avoid the scratches when you are removing the post for the first time.....and I don't think there is an answer except pure luck (which he apparently didn't have this time).....

Mark

Pictures 1 and 2 in the post above this one show how to best avoid scrtaches. Sometimes they're inevitable.

Another thing that helps is to use a flat bladed screwdriver to gently pry apart the tabs on the seat post binder. That is, if it has one. This doesn't work obviously on posts with a separate collar.

Bicycle cavities need attention prior to using them. This is how I approach each cavity (http://www.mytenspeeds.com/My_TenSpeeds_1/Site%20Contents/How_To_Do_It/How_To_Do_It_FrameCavityPrep.htm)(there are three - bb, seat post, head tube).

I always forget what good stuff you have on that site!

I like to use a small metal wedge made for re-handling a hatchet or axe to slightly separate the slot. Only about 1/2 inch wide and seems to have a more gradual taper than a screwdriver blade.

Good stuff. I'm gonna have to file this thing some.
Now I need to get a TA crank puller so I don't trash the BB in the process.
I love fancy bikes.

Mike

Cylinder hone

http://i1128.photobucket.com/albums/m483/MichaelAngelo54/Tandem/Brakehone.jpg
what Mike shows here is called a FlexHone, it's a brand name and a good product...absolutely must be used with oil, and they sell their own brand, but I've subbed motor oil with no tragedy. What I've always been taught is a brake cylinder hone is shown above (#11) in miamijim's excellent tutorial, these have 2 or 3 stones on spring-loaded arms...you can use them dry or with brake fluid as a lube, you'd NEVER use oil honing a brake cylinder. For a seat tube, and a tool that will never see brake use, I'd use oil.

Bicycle cavities need attention prior to using them. This is how I approach each cavity (http://www.mytenspeeds.com/My_TenSpeeds_1/Site%20Contents/How_To_Do_It/How_To_Do_It_FrameCavityPrep.htm)(there are three - bb, seat post, head tube).


What a great and informative site... Bookmarked!! THANKS!!

andy

Well this is my method - Take out the seat binder bolt. Gently spread the frame where the seat binder
bolt was. Spray a liberal amount of WD-40 around the seatpost and frame where the binder bolt went.
Now, take a soft rubber mallet and gently tap on the underside of the seat rails or the seatpost itself in
an upward direction.

The seatpost will come straight out without any twisting motion. Next, take a flat file, and file off
the sharp edges on the frame where the clamp area of the frame is, and where the binder was. This will
eliminate a lot of gouging in the future if you twist the post while removing it.

Once you have it out, if there are any zig-zag marks from the previous owner, you can use 400 emery
to smooth off the marks. You can then go to 600 emery ( wet sand ) to polish up the post. Next, use
a product like Mothers to bring the seatpost up to a brilliant shine.



Johnnybee.

Rubber mallet. Why didn't I think of that. Well, next bike.

Rubber mallet. Why didn't I think of that. Well, next bike.



Glad to help Ben. Don't forget to clean (de-burr) and lube the seatube before putting in the seatpost.

Johnnybee.