ugh why am I even asking

[Antaresia]

I can't decide if I should bail on my friends and go for a 50km ride this weekend or not.

Then I realized that if I was planning on asking that question HERE, that kind of indicates what answer is in my little bikey heart.

I made plans to go to this comic book convention in Seattle, it's pretty big. And a 3 day pass is SIXTY bucks. Jeez, I don't like comic books so much that I want to pay that much to look a them for 3 days.

On the other hand, there is also this going on:
http://www.randonneurs.bc.ca/pacpop/rout_50k.html
it's $18 and you get a pin if you do it.

I am so conflicted. So close to saying "sorry guys, there was a screw up with the vacation scheduled at work and I can't make it"

And I love my new-used single speed, but there are issues with the seat post. I replaced it, but it still slides down every now and then. IDK what else to do to fix that, I'm tightening the bolt as hard as I can.

[Antaresia]

okay, regarding the seat post, I had a bike-friend suggest I make my own shim from a cut-up pop can. Good idea or bad idea?
It sounds legit.

[Catrin]

Can't give any advice as I am SO far from being mechanically inclined, but enjoy your ride this weekend

[tzvia]

If the bike is steel, it may be that collar where the 'pinch bolt' tightens around the seatpost got stretched from being over tightened in the past. Coke can shim sounds just fine (if the thickness is ok). You could also pick up some metal tape from the hardware store and use that as a shim if the amount of thickness needed is not too great. It may sound counter-intuitive, but remember to use a thin amount of grease when reinstalling the post to keep the parts from seizing on each other.

[goride]

Regarding the seat post - I had a similar problem with a carbon seat post on an aluminum bike (so not quite the same). The seat post would creep down in the tube and I was having to adjust it back up about every 10 miles. My LBS used a gritty gel of some type on the post and then reinserted it in the seat tube. End of problem. Depending on how loose your seat post is, that might work for you.

[OakLeaf]

What is the frame made of? What about the seatpost? Any chance the new seatpost you got is the wrong size? Four-tenths of a millimeter (just for instance) is the difference between 31.2 and 31.6 and it could be the width of a piece of grit on your calipers or the old seatpost you were measuring...