loose seatpost help
 

so i have a pake frame that i recently built. i tighten the seat post as tight as i can and it is still loose. i can ride it, but if i bump the seat it will get knocked crooked. it doesn't take much. i am positive the seat post is the correct size. any suggestions?

1. it's actually not the correct size (you may have bent the top of your seat tube and it's looks right but it ain't)
2. seat clamp/bolt are bad
3. you've over tightened it and dented your post, thus reducing the diameter and allowing for some play
4. Post is too short and not enough is engaged (you should have 2" below the bottom of the intersection of your TT and ST to ensure your frame will support it and not crack)

You should ALWAYS be leary of "tightening as hard as I can" for just about every part it is too much. I live by only as tight as necessary. I actually dented a thomson seat post once by not paying attention and over tightening, sad day for sure! If you have lubed your post that could accentuate any of these possibilities but don't take it off, lube is your friend especially on places like seat posts that can seize up fairly easily.

i started with a 10 buck generic seatpost and i just got a new one today and i still have the problem. i put some grease on the new one but it made it worse so i wiped it off. i have maybe 4" left in the frame so thats not the problem either, and i know the seatpost isn't dented. i would normally never over tighten anything but if i dont it is way too loose.

i am guessing pake just uses incredibly cheap bolts. i will start there i guess and if that doesn't work i don't know what else to do.

what size is the seatpost?

One more option, there could be some paint inside that is flaking off and keeping you from getting correct contact, if so carefully sand it all out and try again. I'd be willing to but a lot of money on you having the wrong size though.

it's a 27.2, i am almost positive it's correct. i checked inside the frame and it was all clear, but i can try and give it a light sand.

Responsive semi-track geometry.
Full 4130 CrMo tubeset. Horizonal dropouts. 120mm rear hub spacing.
1" headset size.
68mm BB shell.
One set of cage bosses on downtube.
Drilled for rear brake, but no cable guides. Clearance for 28c tires.
Decals: Removable w/o stripping clearcoat. Optional unicrown steel fork: 38mm rake, set up to take brakes, threadless 1" steerer.
Color: Basic Black
Fits 27.2mm post
Sizes: 49 to 61cm (new)

The only way to be sure is to measure the seat tube. Get some calipers from the hardware store and measure all the way around(on the inside of the seat tube). Also measure the seat post.

LBS should have calipers; maybe they'd measure it for you for free. I know they would if you bought the seat tube from them.

Is the seatpost rotating? Or is the seatpost clamp (if you have pillar type) rotating on the seatpost itself? Do you even have a seatpost like this? Or is it laprade?

Check the clamp make sure it's the right size. Inspect it for damage, it might be cracked.

Have you tried a shim?

the seatpost is rotating, sorry i'm new to bikes. i dont know what a pillar type or laprade is. its a soma seatpost like this.http://store.somafab.com/somaseatpost.html

it says right on the seat post it's a 27.2, would it still be worth it to measure it?

I had this problem on my Rush Hour. LBS added a little grit to the stem and then tightened it down. hasn't budged a millimeter since. Go try it!

cool, i am just gonna take it to them if a new bolt doesn't fix it. i bet they see it all the time.

my pake is 27.0 since this frame was introduced the seatpost size has changed from 26.8 > 27.0 > 27.2 current..

Make your own shim out of a tin soda can, it worked for three years on my bike ;)

then what happened?

i tried the soda can shim. there wasn't really enough space to get it in so i could only use a little piece but it didn't work.

can you use carbon paste on steel frame/al post to get a good seal?

"I started with a 10 buck generic seatpost"

Was it 27.2? If not, and you tried to tighten the seattube clamp, you probably pinched the adjustment slit in the tube too much and now it can't tighten up anymore.

Replace the binder bolt. My friend who sells Pakes at his shop just tosses the binder bolts when he gets the frames because they are such crap that they break almost immediately. The fact that the problem is still occuring after replacing the seatpost should be a sign that the bolt is not clamping down enough. While a mis-shaped/mis-sized seat post isn't entirely out of the question (a friend's Jamis Sputnik stock seatpost wouldn't stay up despite changing binder bolts - the problem was only solved when she got a new seatpost), it doesn't sound like that is the problem.

i replaced the binder bolt about a month ago and it's been fine since.