Quill Wedge seatpost making

General Discussion
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Hi all !
I’d like to make a quill or wedge seatpost for a rando bike I made.
Why ? Just because it’s nice and could be a fun project.

I used a 29.8 external butted seat tube. If it works I could cut the top of the seat tube to look like seat clusters with seatpost clamp integrated in seatstays (please tell me how to call it).

Does someone have something to share about this ? Any concerns ?
Would it work with normal post extension ? Do I have to place the wedge in the butted area (obvious ?) ? What modern post would be good candidate for doing this ?

Kiss !

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I don’t see why it wouldn’t work. Don’t carbon fibre bikes often have this kind of thing these days? Yes make sure the wedge is in the butted area.

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I think it sounds like a fun challenge, and I think it is possible to make it very nice, but many of us have grown up with the horror of wedged stems(I exaggerate), so from that experience, here are a few things you might try:

  • go for a post with thick aluminum wall, so the wedge has a good surface to act upon. This Cult railed post could be a decent candidate.

  • face the wedge such that sitting down will not highlight the slop in the system

  • probably use friction paste to help avoid movement.

  • consider an overly long wedge for good thread engagement and decreased slop (see Wedgie Jackson below).

  • make the post as close a fit as possible to decrease slop.

Finally, here are some references from the BMX world of the past:

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Thank’s for advising me !
Cult one seem’s good candidate but is 25.4.
Was thinking about a thomson as it seem’s quite sturdy aswell.

Sorry I did not get this one.

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Usually the wedge pushes the post or stem to a certain side of the hole that it’s in. Orientation of the post will either be supported with rider weight on it, or clunk to the other side of the hole when you sit down. I guess that doesn’t really affect the build cus the post can be flipped.

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I made one a couple years ago for a bike with a broken seat clamp. It’s a cromor frame so thick ish but not beefy either, and it hasn’t cracked or bulged. I kept it full of anti seize and it’s still easy to move around. I used an ultegra 6600 seatpost (i know sue me) and the offset makes it easier to drill the top to add a bolt, which i took from a cheap extra long stem (with a hollow channel saddle you get easier access). Honestly its a quick project and i think it looks good, go for it^^